/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: condition.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Evaluate [condition] blocks: exists_file, exists_file_any, command. Returns pass/fail + reason.

******************************************************************************/

module condition

import core.str as str
import io.file
import config

export
    type ConditionResult
    fn  evaluate_conditions(def: config.ServiceDef): ConditionResult
    fn  cond_passed(r: ConditionResult): bool
    fn  cond_reason(r: ConditionResult): string
end export

type ConditionResult = struct
    passed: bool
    reason: string
end ConditionResult

extern "C" fn run_command_with_timeout(cmd: string, timeout_sec: int): int

// Sentinel return values from run_command_with_timeout.
fn TIMEOUT_RC(): int     return 0 - 2 end TIMEOUT_RC
fn NOT_FOUND_RC(): int   return 0 - 3 end NOT_FOUND_RC
fn EXEC_FAILED_RC(): int return 0 - 4 end EXEC_FAILED_RC

fn cond_passed(r: ConditionResult): bool
    return r.passed
end cond_passed

fn cond_reason(r: ConditionResult): string
    return r.reason
end cond_reason

fn evaluate_conditions(def: config.ServiceDef): ConditionResult
    // exists_file: single path must exist
    let f = config.svc_cond_exists_file(def)
    if str.length(f) > 0
        if not file.fileExists(f)
            return ConditionResult{
                passed: false,
                reason: str.concat("missing ", f)
            }
        end if
    end if

    // exists_file_any: at least one must exist
    let n = config.svc_cond_exists_file_any_count(def)
    if n > 0
        let paths = config.svc_cond_exists_file_any(def)
        mut found = false
        mut i = 0
        while i < n
            if file.fileExists(paths[i])
                found = true
            end if
            i = i + 1
        end while
        if not found
            return ConditionResult{
                passed: false,
                reason: "none of exists_file_any paths exist"
            }
        end if
    end if

    // command: exit 0 = pass; non-zero = fail; bounded by 5-second timeout
    let cmd = config.svc_cond_command(def)
    if str.length(cmd) > 0
        let rc = run_command_with_timeout(cmd, 5)
        if rc != 0
            if rc == TIMEOUT_RC()
                return ConditionResult{ passed: false, reason: "command timeout" }
            elif rc == NOT_FOUND_RC()
                return ConditionResult{ passed: false, reason: str.concat("command not found: ", cmd) }
            elif rc == EXEC_FAILED_RC()
                return ConditionResult{ passed: false, reason: "command exec failed" }
            else
                return ConditionResult{
                    passed: false,
                    reason: str.concat("command exit=", int_to_str(rc))
                }
            end if
        end if
    end if

    return ConditionResult{ passed: true, reason: "" }
end evaluate_conditions

// Local int_to_str — Reef has no stdlib version (RFE-004).
// Copied verbatim from contract.reef / socket.reef.
fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: config.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: TOML service definition parser and ServiceDef types

******************************************************************************/

module config

import encoding.toml
import io.file
import io.dir
import core.str
import core.result as res

export
    type ServiceDef

    // Constants for service type
    fn SERVICE_TYPE_DAEMON(): int
    fn SERVICE_TYPE_ONESHOT(): int
    fn SERVICE_TYPE_TASK(): int

    // Constants for restart policy
    fn RESTART_ALWAYS(): int
    fn RESTART_FAILURE(): int
    fn RESTART_NEVER(): int

    // Constants for stop method
    fn STOP_METHOD_CONTRACT(): int
    fn STOP_METHOD_EXEC(): int

    // Constants for runlevel mode (which runlevel(s) include this service)
    fn RUNLEVEL_MULTI(): int
    fn RUNLEVEL_SINGLE(): int
    fn RUNLEVEL_ALWAYS(): int

    // Service definition constructor
    fn new_service_def(): ServiceDef

    // Accessors
    fn svc_name(svc: ServiceDef): string
    fn svc_description(svc: ServiceDef): string
    fn svc_type(svc: ServiceDef): int
    fn svc_start_cmd(svc: ServiceDef): string
    fn svc_stop_cmd(svc: ServiceDef): string
    fn svc_working_dir(svc: ServiceDef): string
    fn svc_environment(svc: ServiceDef): [string]
    fn svc_environment_count(svc: ServiceDef): int
    fn svc_user(svc: ServiceDef): string
    fn svc_group(svc: ServiceDef): string
    fn svc_stop_method(svc: ServiceDef): int
    fn svc_stop_signal(svc: ServiceDef): string
    fn svc_stop_timeout(svc: ServiceDef): int
    fn svc_requires(svc: ServiceDef): [string]
    fn svc_requires_count(svc: ServiceDef): int
    fn svc_after(svc: ServiceDef): [string]
    fn svc_after_count(svc: ServiceDef): int
    fn svc_conflicts(svc: ServiceDef): [string]
    fn svc_conflicts_count(svc: ServiceDef): int
    fn svc_contract_param(svc: ServiceDef): [string]
    fn svc_contract_param_count(svc: ServiceDef): int
    fn svc_contract_fatal(svc: ServiceDef): [string]
    fn svc_contract_fatal_count(svc: ServiceDef): int
    fn svc_restart_policy(svc: ServiceDef): int
    fn svc_restart_delay(svc: ServiceDef): int
    fn svc_max_retries(svc: ServiceDef): int
    fn svc_runlevel_mode(svc: ServiceDef): int
    fn svc_cond_exists_file(svc: ServiceDef): string
    fn svc_cond_exists_file_any(svc: ServiceDef): [string]
    fn svc_cond_exists_file_any_count(svc: ServiceDef): int
    fn svc_cond_command(svc: ServiceDef): string

    // Human-readable names for type/policy constants
    fn service_type_name(t: int): string
    fn restart_policy_name(p: int): string
    fn stop_method_name(m: int): string
    fn runlevel_mode_name(m: int): string

    // Parsing
    // parse_service: parse a service.toml file. `name` is taken from the
    // enclosing directory name (not from the TOML). `svc_dir` is the
    // directory containing the TOML, used to resolve "./" relative paths.
    fn parse_service(filepath: string, name: string, svc_dir: string, svc: ServiceDef): bool
    fn scan_enabled(config_dir: string, names: [string], max_names: int): int
    fn load_enabled_services(config_dir: string, services: [ServiceDef], max_services: int): int
end export

// FFI: helpers.c — resolve a symlink or path to its canonical absolute form.
// Returns the resolved path, or "" on any error (dangling link, permission
// denied, path does not exist, etc.).
extern "C" fn zyginit_readlink_resolved(path: string): string

// ============================================================================
// Constants
// ============================================================================

fn SERVICE_TYPE_DAEMON(): int
    return 1
end SERVICE_TYPE_DAEMON

fn SERVICE_TYPE_ONESHOT(): int
    return 2
end SERVICE_TYPE_ONESHOT

fn SERVICE_TYPE_TASK(): int
    return 3
end SERVICE_TYPE_TASK

fn RESTART_ALWAYS(): int
    return 1
end RESTART_ALWAYS

fn RESTART_FAILURE(): int
    return 2
end RESTART_FAILURE

fn RESTART_NEVER(): int
    return 3
end RESTART_NEVER

fn STOP_METHOD_CONTRACT(): int
    return 1
end STOP_METHOD_CONTRACT

fn STOP_METHOD_EXEC(): int
    return 2
end STOP_METHOD_EXEC

// Runlevel modes — which runlevel(s) include this service in the active
// set. Default is MULTI, matching legacy zyginit behavior (services run
// in multi-user mode, are stopped on transitions to single-user).
fn RUNLEVEL_MULTI(): int
    return 0
end RUNLEVEL_MULTI

fn RUNLEVEL_SINGLE(): int
    return 1
end RUNLEVEL_SINGLE

fn RUNLEVEL_ALWAYS(): int
    return 2
end RUNLEVEL_ALWAYS

// ============================================================================
// ServiceDef type
// ============================================================================

type ServiceDef = struct
    name: string
    description: string
    service_type: int

    start_cmd: string
    stop_cmd: string
    working_dir: string
    environment: [string]
    environment_count: int
    user: string
    group: string

    stop_method: int
    stop_signal: string
    stop_timeout: int

    requires: [string]
    requires_count: int
    after: [string]
    after_count: int
    conflicts: [string]
    conflicts_count: int

    contract_param: [string]
    contract_param_count: int
    contract_fatal: [string]
    contract_fatal_count: int

    restart_policy: int
    restart_delay: int
    max_retries: int

    // Runlevel mode: RUNLEVEL_MULTI (default), RUNLEVEL_SINGLE, or
    // RUNLEVEL_ALWAYS. Determines whether the service is in the active
    // set for single-user mode, multi-user mode, or both.
    runlevel_mode: int

    // [condition] block fields — all optional, default to empty/zero.
    cond_exists_file: string
    cond_exists_file_any: [string]
    cond_exists_file_any_count: int
    cond_command: string
end ServiceDef

fn new_service_def(): ServiceDef
    return ServiceDef{
        name: "",
        description: "",
        service_type: SERVICE_TYPE_DAEMON(),
        start_cmd: "",
        stop_cmd: "",
        working_dir: "",
        environment: new [string](16),
        environment_count: 0,
        user: "",
        group: "",
        stop_method: STOP_METHOD_CONTRACT(),
        stop_signal: "TERM",
        stop_timeout: 60,
        requires: new [string](16),
        requires_count: 0,
        after: new [string](16),
        after_count: 0,
        conflicts: new [string](16),
        conflicts_count: 0,
        contract_param: new [string](8),
        contract_param_count: 0,
        contract_fatal: new [string](8),
        contract_fatal_count: 0,
        restart_policy: RESTART_FAILURE(),
        restart_delay: 5,
        max_retries: 3,
        runlevel_mode: RUNLEVEL_MULTI(),
        cond_exists_file: "",
        cond_exists_file_any: new [string](16),
        cond_exists_file_any_count: 0,
        cond_command: ""
    }
end new_service_def

// ============================================================================
// Accessors
// ============================================================================

fn svc_name(svc: ServiceDef): string
    return svc.name
end svc_name

fn svc_description(svc: ServiceDef): string
    return svc.description
end svc_description

fn svc_type(svc: ServiceDef): int
    return svc.service_type
end svc_type

fn svc_start_cmd(svc: ServiceDef): string
    return svc.start_cmd
end svc_start_cmd

fn svc_stop_cmd(svc: ServiceDef): string
    return svc.stop_cmd
end svc_stop_cmd

fn svc_working_dir(svc: ServiceDef): string
    return svc.working_dir
end svc_working_dir

fn svc_environment(svc: ServiceDef): [string]
    return svc.environment
end svc_environment

fn svc_environment_count(svc: ServiceDef): int
    return svc.environment_count
end svc_environment_count

fn svc_user(svc: ServiceDef): string
    return svc.user
end svc_user

fn svc_group(svc: ServiceDef): string
    return svc.group
end svc_group

fn svc_stop_method(svc: ServiceDef): int
    return svc.stop_method
end svc_stop_method

fn svc_stop_signal(svc: ServiceDef): string
    return svc.stop_signal
end svc_stop_signal

fn svc_stop_timeout(svc: ServiceDef): int
    return svc.stop_timeout
end svc_stop_timeout

fn svc_requires(svc: ServiceDef): [string]
    return svc.requires
end svc_requires

fn svc_requires_count(svc: ServiceDef): int
    return svc.requires_count
end svc_requires_count

fn svc_after(svc: ServiceDef): [string]
    return svc.after
end svc_after

fn svc_after_count(svc: ServiceDef): int
    return svc.after_count
end svc_after_count

fn svc_conflicts(svc: ServiceDef): [string]
    return svc.conflicts
end svc_conflicts

fn svc_conflicts_count(svc: ServiceDef): int
    return svc.conflicts_count
end svc_conflicts_count

fn svc_contract_param(svc: ServiceDef): [string]
    return svc.contract_param
end svc_contract_param

fn svc_contract_param_count(svc: ServiceDef): int
    return svc.contract_param_count
end svc_contract_param_count

fn svc_contract_fatal(svc: ServiceDef): [string]
    return svc.contract_fatal
end svc_contract_fatal

fn svc_contract_fatal_count(svc: ServiceDef): int
    return svc.contract_fatal_count
end svc_contract_fatal_count

fn svc_restart_policy(svc: ServiceDef): int
    return svc.restart_policy
end svc_restart_policy

fn svc_restart_delay(svc: ServiceDef): int
    return svc.restart_delay
end svc_restart_delay

fn svc_max_retries(svc: ServiceDef): int
    return svc.max_retries
end svc_max_retries

fn svc_runlevel_mode(svc: ServiceDef): int
    return svc.runlevel_mode
end svc_runlevel_mode

fn svc_cond_exists_file(svc: ServiceDef): string
    return svc.cond_exists_file
end svc_cond_exists_file

fn svc_cond_exists_file_any(svc: ServiceDef): [string]
    return svc.cond_exists_file_any
end svc_cond_exists_file_any

fn svc_cond_exists_file_any_count(svc: ServiceDef): int
    return svc.cond_exists_file_any_count
end svc_cond_exists_file_any_count

fn svc_cond_command(svc: ServiceDef): string
    return svc.cond_command
end svc_cond_command

// ============================================================================
// Human-readable names
// ============================================================================

fn service_type_name(t: int): string
    if t == SERVICE_TYPE_DAEMON()
        return "daemon"
    elif t == SERVICE_TYPE_ONESHOT()
        return "oneshot"
    elif t == SERVICE_TYPE_TASK()
        return "task"
    end if
    return "unknown"
end service_type_name

fn restart_policy_name(p: int): string
    if p == RESTART_ALWAYS()
        return "always"
    elif p == RESTART_FAILURE()
        return "failure"
    elif p == RESTART_NEVER()
        return "never"
    end if
    return "unknown"
end restart_policy_name

fn stop_method_name(m: int): string
    if m == STOP_METHOD_CONTRACT()
        return "contract"
    elif m == STOP_METHOD_EXEC()
        return "exec"
    end if
    return "unknown"
end stop_method_name

fn runlevel_mode_name(m: int): string
    if m == RUNLEVEL_MULTI()
        return "multi"
    elif m == RUNLEVEL_SINGLE()
        return "single"
    elif m == RUNLEVEL_ALWAYS()
        return "always"
    end if
    return "unknown"
end runlevel_mode_name

// Parse runlevel mode string to constant
fn parse_runlevel_mode(mode_str: string): int
    if mode_str == "multi"
        return RUNLEVEL_MULTI()
    elif mode_str == "single"
        return RUNLEVEL_SINGLE()
    elif mode_str == "always"
        return RUNLEVEL_ALWAYS()
    end if
    // Unknown/empty — default to multi (legacy behavior)
    return RUNLEVEL_MULTI()
end parse_runlevel_mode

// ============================================================================
// Parsing helpers
// ============================================================================

// Parse service type string to constant
fn parse_service_type(type_str: string): int
    if type_str == "daemon"
        return SERVICE_TYPE_DAEMON()
    elif type_str == "oneshot"
        return SERVICE_TYPE_ONESHOT()
    elif type_str == "task"
        return SERVICE_TYPE_TASK()
    end if
    if type_str == "transient"
        println("zyginit: warning: type='transient' is deprecated in 0.2.0 — treating as 'task' (rename in your TOML)")
        return SERVICE_TYPE_TASK()
    end if
    return SERVICE_TYPE_DAEMON()
end parse_service_type

// Parse restart policy string to constant
fn parse_restart_policy(policy_str: string): int
    if policy_str == "always"
        return RESTART_ALWAYS()
    elif policy_str == "failure"
        return RESTART_FAILURE()
    elif policy_str == "never"
        return RESTART_NEVER()
    end if
    return RESTART_FAILURE()
end parse_restart_policy

// Parse stop method string to constant
fn parse_stop_method(method_str: string): int
    if method_str == "contract"
        return STOP_METHOD_CONTRACT()
    elif method_str == "exec"
        return STOP_METHOD_EXEC()
    end if
    return STOP_METHOD_CONTRACT()
end parse_stop_method

// Read an inline-array TOML field from the flattened key/value model.
//
// Reef 0.7.5+ flattens `key = ["a", "b"]` into indexed keys `key.0`, `key.1`,
// ... plus a synthetic `key.#len` count marker — there is no longer a single
// `key` entry holding the raw "[...]" text. This reads up to `max_items`
// elements of `prefix` into `result` and returns the number stored. A missing
// field or empty array yields 0.
fn read_toml_array(keys: [string], vals: [string], count: int, prefix: string, result: [string], max_items: int): int
    let len_key = str.concat(prefix, ".#len")
    if not toml.toml_has_key(keys, vals, count, len_key)
        return 0
    end if
    let n = toml.toml_get_int(keys, vals, count, len_key)
    mut stored = 0
    mut i = 0
    while i < n and stored < max_items
        let item_key = str.concat(str.concat(prefix, "."), str.from_int(i))
        if toml.toml_has_key(keys, vals, count, item_key)
            result[stored] = toml.toml_get(keys, vals, count, item_key)
            stored = stored + 1
        end if
        i = i + 1
    end while
    return stored
end read_toml_array

// ============================================================================
// Service parsing
// ============================================================================

// Resolve a path that may start with "./" to an absolute path using
// the service's directory as the base. Absolute paths (starting with "/")
// and empty strings are returned unchanged. "./foo" becomes
// "<svc_dir>/foo". This allows service.toml to reference companion
// scripts as "./start.sh" without hard-coding the install path.
fn resolve_exec_path(raw: string, svc_dir: string): string
    let raw_len = str.length(raw)
    if raw_len == 0
        return raw
    end if
    // Absolute paths pass through unchanged
    if raw[0] == '/'
        return raw
    end if
    // "./" prefix: strip the prefix and join with svc_dir
    if raw_len >= 2
        if raw[0] == '.' and raw[1] == '/'
            let rel = str.substring(raw, 2, raw_len - 2)
            return str.concat(str.concat(svc_dir, "/"), rel)
        end if
    end if
    // No prefix — return as-is (let exec find it via PATH)
    return raw
end resolve_exec_path

// Parse a single service.toml file into a ServiceDef.
// `name`    — service name derived from the enclosing directory name.
//             The TOML need not (and should not) contain service.name.
// `svc_dir` — absolute path to the directory containing this service.toml;
//             used to resolve "./"-prefixed exec paths.
// Returns true on success.
fn parse_service(filepath: string, name: string, svc_dir: string, svc: ServiceDef): bool
    if not file.fileExists(filepath)
        return false
    end if

    let content_r = file.readFile(filepath)
    if res.is_err(content_r)
        return false
    end if
    let content = res.unwrap_ok(content_r)
    if str.length(content) == 0
        return false
    end if

    let keys = toml.toml_alloc_keys()
    let vals = toml.toml_alloc_values()
    let count_r = toml.toml_parse(content, keys, vals)
    if res.is_err(count_r)
        return false
    end if
    let count = res.unwrap_ok(count_r)

    if count == 0
        return false
    end if

    // Service name comes from the directory name, not from a TOML field.
    svc.name = name

    // [service] section — all optional (type defaults to daemon)
    if toml.toml_has_key(keys, vals, count, "service.description")
        svc.description = toml.toml_get(keys, vals, count, "service.description")
    end if

    if toml.toml_has_key(keys, vals, count, "service.type")
        svc.service_type = parse_service_type(toml.toml_get(keys, vals, count, "service.type"))
    end if

    // [exec] section — start is required
    if not toml.toml_has_key(keys, vals, count, "exec.start")
        return false
    end if
    svc.start_cmd = resolve_exec_path(
        toml.toml_get(keys, vals, count, "exec.start"), svc_dir)

    if toml.toml_has_key(keys, vals, count, "exec.stop")
        svc.stop_cmd = resolve_exec_path(
            toml.toml_get(keys, vals, count, "exec.stop"), svc_dir)
    end if

    if toml.toml_has_key(keys, vals, count, "exec.working_directory")
        svc.working_dir = toml.toml_get(keys, vals, count, "exec.working_directory")
    end if

    svc.environment_count = read_toml_array(keys, vals, count, "exec.environment", svc.environment, 16)

    if toml.toml_has_key(keys, vals, count, "exec.user")
        svc.user = toml.toml_get(keys, vals, count, "exec.user")
    end if

    if toml.toml_has_key(keys, vals, count, "exec.group")
        svc.group = toml.toml_get(keys, vals, count, "exec.group")
    end if

    // [stop] section — all optional with defaults
    if toml.toml_has_key(keys, vals, count, "stop.method")
        svc.stop_method = parse_stop_method(toml.toml_get(keys, vals, count, "stop.method"))
    end if

    if toml.toml_has_key(keys, vals, count, "stop.signal")
        svc.stop_signal = toml.toml_get(keys, vals, count, "stop.signal")
    end if

    if toml.toml_has_key(keys, vals, count, "stop.timeout")
        svc.stop_timeout = toml.toml_get_int(keys, vals, count, "stop.timeout")
    end if

    // [dependencies] section — inline arrays
    svc.requires_count = read_toml_array(keys, vals, count, "dependencies.requires", svc.requires, 16)
    svc.after_count = read_toml_array(keys, vals, count, "dependencies.after", svc.after, 16)
    svc.conflicts_count = read_toml_array(keys, vals, count, "dependencies.conflicts", svc.conflicts, 16)

    // [contract] section — inline arrays
    svc.contract_param_count = read_toml_array(keys, vals, count, "contract.param", svc.contract_param, 8)
    svc.contract_fatal_count = read_toml_array(keys, vals, count, "contract.fatal", svc.contract_fatal, 8)

    // [restart] section — all optional with defaults
    if toml.toml_has_key(keys, vals, count, "restart.on")
        svc.restart_policy = parse_restart_policy(toml.toml_get(keys, vals, count, "restart.on"))
    end if

    if toml.toml_has_key(keys, vals, count, "restart.delay")
        svc.restart_delay = toml.toml_get_int(keys, vals, count, "restart.delay")
    end if

    if toml.toml_has_key(keys, vals, count, "restart.max_retries")
        svc.max_retries = toml.toml_get_int(keys, vals, count, "restart.max_retries")
    end if

    // [runlevel] section — optional, default mode="multi"
    if toml.toml_has_key(keys, vals, count, "runlevel.mode")
        svc.runlevel_mode = parse_runlevel_mode(
            toml.toml_get(keys, vals, count, "runlevel.mode"))
    end if

    // [condition] section — all optional
    if toml.toml_has_key(keys, vals, count, "condition.exists_file")
        svc.cond_exists_file = toml.toml_get(keys, vals, count, "condition.exists_file")
    end if

    svc.cond_exists_file_any_count = read_toml_array(keys, vals, count, "condition.exists_file_any", svc.cond_exists_file_any, 16)

    if toml.toml_has_key(keys, vals, count, "condition.command")
        svc.cond_command = toml.toml_get(keys, vals, count, "condition.command")
    end if

    return true
end parse_service

// ============================================================================
// Service scanning
// ============================================================================

// Scan the enabled.d/ directory and return the names of enabled services.
//
// In the 0.2.x layout each entry in enabled.d/ is a symlink whose name is
// the service name and whose target is the service's directory inside
// services/. For example:
//
//   enabled.d/sshd  ->  ../services/sshd/
//
// We resolve every symlink via zyginit_readlink_resolved (realpath) and
// reject entries that do not resolve to a path under
// <config_dir>/services/. This prevents a symlink escaping the config
// tree from loading an arbitrary TOML file.
//
// Returns the number of names written into `names`.
fn scan_enabled(config_dir: string, names: [string], max_names: int): int
    let enabled_dir = str.concat(config_dir, "/enabled.d")
    let services_prefix = str.concat(config_dir, "/services/")
    let prefix_len = str.length(services_prefix)

    if not dir.dir_exists(enabled_dir)
        return 0
    end if

    let entries_r = dir.list_dir(enabled_dir)
    if res.is_err(entries_r)
        return 0
    end if
    let entries = res.unwrap_ok(entries_r)
    let entry_count = entries.length()

    mut name_count = 0
    mut i = 0
    while i < entry_count and name_count < max_names
        let entry = entries[i]
        let link_path = str.concat(str.concat(enabled_dir, "/"), entry)
        let target = zyginit_readlink_resolved(link_path)

        // Reject dangling symlinks (target == "")
        if str.length(target) == 0
            println("zyginit: enabled.d/" + entry + ": dangling symlink — ignoring")
        else
            // Reject symlinks that escape the services/ subtree.
            // Inline starts-with check: compare the first prefix_len chars.
            let target_len = str.length(target)
            mut has_prefix = false
            if target_len >= prefix_len
                if str.substring(target, 0, prefix_len) == services_prefix
                    has_prefix = true
                end if
            end if

            if not has_prefix
                println("zyginit: enabled.d/" + entry + ": target " + target +
                        " is outside services/ — ignoring")
            else
                names[name_count] = entry
                name_count = name_count + 1
            end if
        end if

        i = i + 1
    end while

    return name_count
end scan_enabled

// Load all enabled services from config_dir.
//
// Walks <config_dir>/services/ to find enabled services (via scan_enabled),
// then for each name locates <config_dir>/services/<name>/service.toml,
// parses it, and loads it into the services array.
//
// If <config_dir>/services/ does not exist, logs a fatal-tier message and
// returns 0. The caller (main.reef) treats a 0 count as "nothing to do"
// and should handle this as an error condition.
//
// Returns the number of services loaded, or -1 if the services/ directory
// does not exist (FATAL configuration error — operator must migrate first).
fn load_enabled_services(config_dir: string, services: [ServiceDef], max_services: int): int
    let services_root = str.concat(config_dir, "/services")
    if not dir.dir_exists(services_root)
        println("zyginit: FATAL: services/ directory not found at " + services_root)
        println("zyginit: run scripts/migrate-layout.sh to convert a 0.1.x tree")
        return 0 - 1
    end if

    let names = new [string](128)
    let name_count = scan_enabled(config_dir, names, 128)

    mut loaded = 0
    mut i = 0
    while i < name_count and loaded < max_services
        let name = names[i]
        let svc_dir = str.concat(str.concat(services_root, "/"), name)
        let toml_path = str.concat(svc_dir, "/service.toml")

        if not file.fileExists(toml_path)
            println("zyginit: services/" + name + "/ missing service.toml — skipping")
        else
            mut svc = new_service_def()
            if parse_service(toml_path, name, svc_dir, svc)
                services[loaded] = svc
                loaded = loaded + 1
            else
                println("zyginit: services/" + name + "/service.toml parse error — skipping")
            end if
        end if

        i = i + 1
    end while

    return loaded
end load_enabled_services

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: contract.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Hammerhead process contract FFI bindings (libcontract)

******************************************************************************/

// Hammerhead process contracts are the kernel mechanism for tracking service
// processes. This module provides Reef wrappers around libcontract.
//
// This module ONLY works on Hammerhead. On Linux, the extern "C"
// functions will fail at link time unless stub implementations are provided.
//
// Reference: Hammerhead libcontract(3LIB), contract(5), process(5)
// Source: hammerhead/usr/src/lib/libcontract/common/

module contract

import sys.fd as fd
import core.str

export
    type Contract

    // Contract event flags (from sys/contract/process.h)
    fn CT_PR_EV_EMPTY(): int
    fn CT_PR_EV_FORK(): int
    fn CT_PR_EV_EXIT(): int
    fn CT_PR_EV_CORE(): int
    fn CT_PR_EV_SIGNAL(): int
    fn CT_PR_EV_HWERR(): int
    fn CT_PR_ALLEVENT(): int
    fn CT_PR_ALLFATAL(): int

    // Contract parameter flags
    fn CT_PR_INHERIT(): int
    fn CT_PR_NOORPHAN(): int
    fn CT_PR_PGRPONLY(): int
    fn CT_PR_REGENT(): int

    // Status detail levels (from sys/contract.h)
    fn CTD_COMMON(): int
    fn CTD_FIXED(): int
    fn CTD_ALL(): int

    // sigsend id type
    fn P_CTID(): int

    // CTFS paths
    fn CTFS_ROOT(): string
    fn CTFS_PROCESS_TEMPLATE(): string
    fn CTFS_PROCESS_LATEST(): string
    fn CTFS_PROCESS_BUNDLE(): string

    // Contract handle constructor
    fn new_contract(id: int, service_name: string): Contract

    // Contract accessors
    fn contract_id(ct: Contract): int
    fn contract_service(ct: Contract): string
    fn contract_bundle_fd(ct: Contract): int

    // Contract lifecycle
    fn setup_template(): int
    fn get_latest_contract(): int
    fn clear_template(tmpl_fd: int): int
    fn open_bundle(): int
    fn kill_contract(contract_id: int, sig: int): int
    fn abandon_contract(contract_id: int): int
    fn adopt_contract(contract_id: int): int
    fn is_contract_empty(contract_id: int): bool

    // Event reading
    fn read_event(bundle_fd: int, out_ctid: [int], out_type: [int]): bool
    fn ack_event(contract_id: int, event_id: int): int
end export

// ============================================================================
// FFI declarations — libcontract
// ============================================================================

// Template management
extern "C" fn ct_tmpl_activate(fd: int): int
extern "C" fn ct_tmpl_clear(fd: int): int
extern "C" fn ct_tmpl_set_informative(fd: int, events: int): int
extern "C" fn ct_tmpl_set_critical(fd: int, events: int): int

// Process contract template
extern "C" fn ct_pr_tmpl_set_fatal(fd: int, events: int): int
extern "C" fn ct_pr_tmpl_set_param(fd: int, params: int): int

// Contract status — ct_stathdl_t is an opaque void*
extern "C" fn ct_status_read(fd: int, detail: int, statp: pointer): int
extern "C" proc ct_status_free(stathdl: pointer)
extern "C" fn ct_status_get_id(stathdl: pointer): int

// Process-contract member list — fills *members and *n. Memory is
// owned by the stathdl, freed by ct_status_free. Requires the status
// to have been read at CTD_FIXED detail or higher (CTD_COMMON does
// not include the member list).
extern "C" fn ct_pr_status_get_members(stathdl: pointer, members: [pointer], n: [int]): int

// Contract control
extern "C" fn ct_ctl_abandon(fd: int): int
extern "C" fn ct_ctl_adopt(fd: int): int

// Contract events — ct_evthdl_t is an opaque void*
extern "C" fn ct_event_read(fd: int, evtp: pointer): int
extern "C" proc ct_event_free(evthdl: pointer)
extern "C" fn ct_event_get_ctid(evthdl: pointer): int
extern "C" fn ct_event_get_type(evthdl: pointer): int
extern "C" fn ct_event_get_flags(evthdl: pointer): int

// Process contract event details
extern "C" fn ct_pr_event_get_exitstatus(evthdl: pointer, status: pointer): int
extern "C" fn ct_pr_event_get_pid(evthdl: pointer, pid: pointer): int

// POSIX — sigsend for contract-wide signaling
extern "C" fn sigsend(idtype: int, id: int, sig: int): int

// POSIX — open/close for ctfs paths
extern "C" fn open(path: string, flags: int): int
extern "C" fn close(fd: int): int

// ============================================================================
// Constants — values from Hammerhead kernel headers
// ============================================================================

// Contract event flags (sys/contract/process.h)
fn CT_PR_EV_EMPTY(): int
    return 1
end CT_PR_EV_EMPTY

fn CT_PR_EV_FORK(): int
    return 2
end CT_PR_EV_FORK

fn CT_PR_EV_EXIT(): int
    return 4
end CT_PR_EV_EXIT

fn CT_PR_EV_CORE(): int
    return 8
end CT_PR_EV_CORE

fn CT_PR_EV_SIGNAL(): int
    return 16
end CT_PR_EV_SIGNAL

fn CT_PR_EV_HWERR(): int
    return 32
end CT_PR_EV_HWERR

fn CT_PR_ALLEVENT(): int
    return 63
end CT_PR_ALLEVENT

fn CT_PR_ALLFATAL(): int
    return 56
end CT_PR_ALLFATAL

// Contract parameter flags (sys/contract/process.h)
fn CT_PR_INHERIT(): int
    return 1
end CT_PR_INHERIT

fn CT_PR_NOORPHAN(): int
    return 2
end CT_PR_NOORPHAN

fn CT_PR_PGRPONLY(): int
    return 4
end CT_PR_PGRPONLY

fn CT_PR_REGENT(): int
    return 8
end CT_PR_REGENT

// Status detail levels (sys/contract.h)
fn CTD_COMMON(): int
    return 0
end CTD_COMMON

fn CTD_FIXED(): int
    return 1
end CTD_FIXED

fn CTD_ALL(): int
    return 2
end CTD_ALL

// sigsend id type for contract (sys/procset.h enum position 13,
// between P_ZONEID=12 and P_CPUID=14). Verified on Hammerhead via
// utils/contract_probe.
fn P_CTID(): int
    return 13
end P_CTID

// CTFS paths
fn CTFS_ROOT(): string
    return "/system/contract"
end CTFS_ROOT

fn CTFS_PROCESS_TEMPLATE(): string
    return "/system/contract/process/template"
end CTFS_PROCESS_TEMPLATE

fn CTFS_PROCESS_LATEST(): string
    return "/system/contract/process/latest"
end CTFS_PROCESS_LATEST

fn CTFS_PROCESS_BUNDLE(): string
    return "/system/contract/process/bundle"
end CTFS_PROCESS_BUNDLE

// Open flags
fn O_RDONLY(): int
    return 0
end O_RDONLY

fn O_WRONLY(): int
    return 1
end O_WRONLY

fn O_RDWR(): int
    return 2
end O_RDWR

// ============================================================================
// Contract type
// ============================================================================

type Contract = struct
    id: int
    service_name: string
    bundle_fd: int
end Contract

fn new_contract(id: int, service_name: string): Contract
    return Contract{
        id: id,
        service_name: service_name,
        bundle_fd: 0 - 1
    }
end new_contract

fn contract_id(ct: Contract): int
    return ct.id
end contract_id

fn contract_service(ct: Contract): string
    return ct.service_name
end contract_service

fn contract_bundle_fd(ct: Contract): int
    return ct.bundle_fd
end contract_bundle_fd

// ============================================================================
// Contract lifecycle functions
// ============================================================================

// Set up a contract template for forking a service.
// Configures: informative=EMPTY, critical=EMPTY|HWERR, fatal=HWERR,
// params=INHERIT|NOORPHAN. Returns template fd on success, -1 on error.
fn setup_template(): int
    let tmpl_fd = open(CTFS_PROCESS_TEMPLATE(), O_RDWR())
    if tmpl_fd < 0
        return 0 - 1
    end if

    // Want informative notification when contract becomes empty
    let rc1 = ct_tmpl_set_informative(tmpl_fd, CT_PR_EV_EMPTY())
    // Critical events: empty (all exited) and hardware error
    let rc2 = ct_tmpl_set_critical(tmpl_fd, CT_PR_EV_EMPTY() + CT_PR_EV_HWERR())
    // Fatal events: hardware error causes contract death
    let rc3 = ct_pr_tmpl_set_fatal(tmpl_fd, CT_PR_EV_HWERR())
    // Parameters: inherit contracts on fork, kill orphans on abandon
    let rc4 = ct_pr_tmpl_set_param(tmpl_fd, CT_PR_INHERIT() + CT_PR_NOORPHAN())

    if rc1 != 0 or rc2 != 0 or rc3 != 0 or rc4 != 0
        close(tmpl_fd)
        return 0 - 1
    end if

    let rc5 = ct_tmpl_activate(tmpl_fd)
    if rc5 != 0
        close(tmpl_fd)
        return 0 - 1
    end if

    return tmpl_fd
end setup_template

// After fork(), retrieve the contract ID for the new child process.
// The kernel writes the latest contract to /system/contract/process/latest.
// Returns contract ID on success, -1 on error.
fn get_latest_contract(): int
    let latest_fd = open(CTFS_PROCESS_LATEST(), O_RDONLY())
    if latest_fd < 0
        return 0 - 1
    end if

    // ct_status_read writes a handle (void*) to an output parameter.
    // We pass a [pointer] array — in C, this is void**, exactly what ct_status_read expects.
    unsafe
        let stathdl_buf = new [pointer](1)
        let rc = ct_status_read(latest_fd, CTD_COMMON(), stathdl_buf)
        close(latest_fd)

        if rc != 0
            return 0 - 1
        end if

        let stathdl = stathdl_buf[0]
        let ctid = ct_status_get_id(stathdl)
        ct_status_free(stathdl)
        return ctid
    end unsafe
end get_latest_contract

// Clear (deactivate) a contract template after fork.
// Returns 0 on success.
fn clear_template(tmpl_fd: int): int
    let rc = ct_tmpl_clear(tmpl_fd)
    close(tmpl_fd)
    return rc
end clear_template

// Open the contract bundle fd for poll()-based event monitoring.
// Returns bundle fd on success, -1 on error.
fn open_bundle(): int
    // O_NONBLOCK (0x80 on Hammerhead): ct_event_read on a blocking fd
    // BLOCKS waiting for events. Our main loop only enters
    // handle_contract_events when poll says the fd is readable, but
    // after we drain the events present at that moment, the next
    // ct_event_read call sees no event and would block indefinitely
    // — wedging the entire main loop, including reap_children for
    // SIGCHLD. With O_NONBLOCK, ct_event_read returns EAGAIN once
    // we've drained, read_event returns false, the while loop in
    // handle_contract_events exits cleanly.
    let bundle_fd = open(CTFS_PROCESS_BUNDLE(), O_RDONLY() + 0x80)
    return bundle_fd
end open_bundle

// Kill all processes in a contract with the given signal.
// Uses sigsend(P_CTID, contract_id, signal).
// Returns 0 on success, -1 on error.
fn kill_contract(contract_id: int, sig: int): int
    return sigsend(P_CTID(), contract_id, sig)
end kill_contract

// Abandon a contract (release ownership, orphan handling applies).
// Opens the contract's ctl fd and issues abandon.
// Returns 0 on success, -1 on error.
fn abandon_contract(contract_id: int): int
    // Build path: /system/contract/process/<id>/ctl
    // ctl file mode is --w--w--w-, so open with O_WRONLY (O_RDWR fails).
    let ctl_path = str.concat(str.concat("/system/contract/process/", int_to_str(contract_id)), "/ctl")
    let ctl_fd = open(ctl_path, O_WRONLY())
    if ctl_fd < 0
        return 0 - 1
    end if
    let rc = ct_ctl_abandon(ctl_fd)
    close(ctl_fd)
    return rc
end abandon_contract

// Adopt an existing contract (for zyginit restart recovery).
// Opens the contract's ctl fd and issues adopt.
// Returns 0 on success, -1 on error.
fn adopt_contract(contract_id: int): int
    let ctl_path = str.concat(str.concat("/system/contract/process/", int_to_str(contract_id)), "/ctl")
    let ctl_fd = open(ctl_path, O_WRONLY())
    if ctl_fd < 0
        return 0 - 1
    end if
    let rc = ct_ctl_adopt(ctl_fd)
    close(ctl_fd)
    return rc
end adopt_contract

// Check whether a contract has zero member processes. Used by the
// post-recovery idempotency step in main.apply_recovered_state — if a
// contract was reported in state.toml but the kernel says it's empty,
// the service exited during the exec gap and we should apply restart
// policy as if a contract-empty event arrived.
//
// Returns true if the contract has zero members OR if the status
// read fails (treat unknown as empty so the recovery path applies
// restart policy rather than leaving a phantom service in RUNNING).
fn is_contract_empty(contract_id: int): bool
    let status_path = str.concat(str.concat("/system/contract/process/", int_to_str(contract_id)), "/status")
    let st_fd = open(status_path, O_RDONLY())
    if st_fd < 0
        return true
    end if

    unsafe
        let stathdl_buf = new [pointer](1)
        // CTD_FIXED includes process-contract-specific fields like the
        // member-PID list, which CTD_COMMON omits.
        let rc = ct_status_read(st_fd, CTD_FIXED(), stathdl_buf)
        close(st_fd)

        if rc != 0
            return true
        end if

        let stathdl = stathdl_buf[0]
        let members_buf = new [pointer](1)
        let n_buf = new [int](1)
        let mrc = ct_pr_status_get_members(stathdl, members_buf, n_buf)
        let n = n_buf[0]
        ct_status_free(stathdl)

        if mrc != 0
            return true
        end if
        return n == 0
    end unsafe
end is_contract_empty

// ============================================================================
// Event reading
// ============================================================================

// Read an event from the contract bundle fd.
// Writes the contract ID to out_ctid[0] and event type to out_type[0].
// Returns true on success, false on error or no event.
fn read_event(bundle_fd: int, out_ctid: [int], out_type: [int]): bool
    unsafe
        let evthdl_buf = new [pointer](1)
        let rc = ct_event_read(bundle_fd, evthdl_buf)

        if rc != 0
            return false
        end if

        let evthdl = evthdl_buf[0]
        out_ctid[0] = ct_event_get_ctid(evthdl)
        out_type[0] = ct_event_get_type(evthdl)

        ct_event_free(evthdl)
        return true
    end unsafe
end read_event

// Acknowledge a contract event.
// Opens the contract's event fd and issues ack.
fn ack_event(contract_id: int, event_id: int): int
    let ev_path = str.concat(str.concat("/system/contract/process/", int_to_str(contract_id)), "/events")
    let ev_fd = open(ev_path, O_RDONLY())
    if ev_fd < 0
        return 0 - 1
    end if
    // For now, we just close — full ack requires ct_ctl_ack on the ctl fd
    close(ev_fd)
    return 0
end ack_event

// ============================================================================
// Helpers
// ============================================================================

// Convert int to string (for building ctfs paths)
fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

end module
/*
 * contract_linux_stubs.c — Linux stub implementations for Hammerhead libcontract FFI
 *
 * These stubs allow zyginit to compile and link on Linux for development.
 * All functions return error codes indicating contracts are not available.
 * On Hammerhead, DO NOT compile this file — link with -lcontract instead.
 */

#include <stddef.h>

/* Template management */
int ct_tmpl_activate(int fd) { return -1; }
int ct_tmpl_clear(int fd) { return -1; }
int ct_tmpl_set_informative(int fd, int events) { return -1; }
int ct_tmpl_set_critical(int fd, int events) { return -1; }

/* Process contract template */
int ct_pr_tmpl_set_fatal(int fd, int events) { return -1; }
int ct_pr_tmpl_set_param(int fd, int params) { return -1; }

/* Contract status */
int ct_status_read(int fd, int detail, void **statp) { return -1; }
void ct_status_free(void *stathdl) { }
int ct_status_get_id(void *stathdl) { return -1; }
int ct_status_get_holder(void *stathdl) { return -1; }
int ct_status_get_state(void *stathdl) { return -1; }
int ct_pr_status_get_members(void *stathdl, void **members, unsigned int *n) {
    (void)stathdl;
    if (members != NULL) *members = NULL;
    if (n != NULL) *n = 0;
    return 0;
}

/* Contract control */
int ct_ctl_abandon(int fd) { return -1; }
int ct_ctl_adopt(int fd) { return -1; }

/* Contract events */
int ct_event_read(int fd, void **evtp) { return -1; }
void ct_event_free(void *evthdl) { }
int ct_event_get_ctid(void *evthdl) { return -1; }
int ct_event_get_type(void *evthdl) { return -1; }
int ct_event_get_flags(void *evthdl) { return -1; }

/* Process contract event details */
int ct_pr_event_get_exitstatus(void *evthdl, int *status) { return -1; }
int ct_pr_event_get_pid(void *evthdl, int *pid) { return -1; }

/* POSIX — sigsend (Hammerhead-specific) */
int sigsend(int idtype, int id, int sig) { return -1; }
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: ctlsocket.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Unix domain socket server for zygctl communication

******************************************************************************/

// Protocol: newline-terminated text commands and responses.
//   Request:  "COMMAND [ARG]\n"
//   Response: plain text lines, connection closed after response.

module ctlsocket

import net.unix as unix
import io.file
import io.dir
import sys.env as env
import supervisor
import config
import shutdown
import core.str
import core.result as res
import version
import ui
import ui_render

export
    fn create_socket(path: string): int
    proc destroy_socket(path: string, server_fd: int)
    proc handle_client(server_fd: int, table: supervisor.ServiceTable)
    fn reload_requested(): bool
    proc clear_reload_flag()
    fn replace_requested(): bool
    proc clear_replace_flag()
    fn replace_wait_seconds(): int
    fn shutdown_requested(): int
    proc clear_shutdown_request()
    fn runlevel_requested(): int
    proc clear_runlevel_request()
end export

extern "C" fn zyginit_symlink(target: string, linkpath: string): int
extern "C" fn zyginit_fsync_path(path: string): int

// Reload flag — set by "reload" command, checked by main event loop
mut g_reload_requested: bool = false

fn reload_requested(): bool
    return g_reload_requested
end reload_requested

proc clear_reload_flag()
    g_reload_requested = false
end clear_reload_flag

// Replace flag — set by "replace" command, checked by main event loop.
// Wait seconds is the optional --wait=N value; 0 means "refuse immediately
// on transient state".
mut g_replace_requested: bool = false
mut g_replace_wait: int = 0

fn replace_requested(): bool
    return g_replace_requested
end replace_requested

proc clear_replace_flag()
    g_replace_requested = false
    g_replace_wait = 0
end clear_replace_flag

fn replace_wait_seconds(): int
    return g_replace_wait
end replace_wait_seconds

// Shutdown request flag — set by halt/reboot/poweroff commands,
// checked by main event loop each iteration.
// 0 = no shutdown requested; non-zero = SHUT_HALT/REBOOT/POWEROFF value.
mut g_shutdown_request: int = 0

fn shutdown_requested(): int
    return g_shutdown_request
end shutdown_requested

proc clear_shutdown_request()
    g_shutdown_request = 0
end clear_shutdown_request

// Runlevel transition request — set by `single` or `multi` socket
// commands, picked up by main loop and applied via runlevel_transition.
// Sentinel values: -1 = no request; 0 = MULTI; 1 = SINGLE (matching
// main.reef's RUNLEVEL_* constants).
mut g_runlevel_request: int = 0 - 1

fn runlevel_requested(): int
    return g_runlevel_request
end runlevel_requested

proc clear_runlevel_request()
    g_runlevel_request = 0 - 1
end clear_runlevel_request

// ============================================================================
// Socket lifecycle
// ============================================================================

// Create and bind a Unix domain socket for listening.
// Returns the server fd on success, -1 on error.
fn create_socket(path: string): int
    // Guard (bug 004): never unlink a socket that a live server is actively
    // listening on. If connect() succeeds, a real zyginit already owns this
    // path — refuse rather than unlink+rebind and hijack control away from the
    // live instance. A stale socket file (no listener) fails to connect, so we
    // fall through and clean it up as before.
    let probe = unix.unix_connect(path)
    if res.is_ok(probe)
        let pfd = res.unwrap_ok(probe)
        let _ = unix.unix_close(pfd)
        println("socket: REFUSING to bind " + path + " — a live server is already listening there")
        return 0 - 1
    end if

    // Remove stale socket file if it exists. unlink failure is non-fatal —
    // the subsequent listen will fail loudly if the path is unusable.
    let unlink_rc = unix.unix_unlink(path)
    if unlink_rc < 0
        println("socket: unlink failed (non-fatal): " + path)
    end if

    let listen_r = unix.unix_listen(path, 5)
    if res.is_err(listen_r)
        println("socket: failed to listen on " + path)
        return 0 - 1
    end if
    let fd = res.unwrap_ok(listen_r)

    println("socket: listening on " + path)
    return fd
end create_socket

// Close the socket and remove the socket file. Called during shutdown.
// We fsync the parent directory after unlink to force the ZFS txg
// commit before uadmin reboots — otherwise the next boot sees a stale
// socket file in /var/run and create_socket fails (unlink runs again
// but bind hits residual state). Without this, zygctl can't connect
// after a zygctl-triggered reboot.
proc destroy_socket(path: string, server_fd: int)
    println("socket: closing server fd")
    unix.unix_close(server_fd)
    let rc = unix.unix_unlink(path)
    if rc < 0
        println("socket: unlink failed: " + path)
    else
        println("socket: unlinked " + path)
    end if
    let _ = zyginit_fsync_path(path)
end destroy_socket

// ============================================================================
// Client handling
// ============================================================================

// Accept a client connection, read command, dispatch, respond, close.
proc handle_client(server_fd: int, table: supervisor.ServiceTable)
    let accept_r = unix.unix_accept(server_fd)
    if res.is_err(accept_r)
        return
    end if
    let client_fd = res.unwrap_ok(accept_r)

    // Read the command (max 1024 bytes)
    let recv_r = unix.unix_recv(client_fd, 1024)
    if res.is_err(recv_r)
        unix.unix_close(client_fd)
        return
    end if
    let input = res.unwrap_ok(recv_r)
    if str.length(input) == 0
        unix.unix_close(client_fd)
        return
    end if

    // Strip trailing newline/whitespace
    let cmd_raw = str.trim_ws(input)

    // Parse command and argument
    let space_pos = str.index_of(cmd_raw, " ")
    mut command = cmd_raw
    mut arg = ""

    if space_pos >= 0
        command = str.substring(cmd_raw, 0, space_pos)
        arg = str.substring(cmd_raw, space_pos + 1, str.length(cmd_raw) - space_pos - 1)
    end if

    // Dispatch
    let response = dispatch_command(command, arg, table)

    // Send response and close
    unix.unix_send(client_fd, response)
    unix.unix_close(client_fd)
end handle_client

// ============================================================================
// Command dispatch
// ============================================================================

fn dispatch_command(command: string, arg: string, table: supervisor.ServiceTable): string
    if command == "status"
        // Parse optional PLAIN modifier: "PLAIN" or "PLAIN <name>"
        mut plain = 0
        mut svc_arg = arg
        if str.length(arg) >= 5 and str.substring(arg, 0, 5) == "plain"
            if str.length(arg) == 5
                plain = 1
                svc_arg = ""
            elif str.substring(arg, 5, 1) == " "
                plain = 1
                svc_arg = str.substring(arg, 6, str.length(arg) - 6)
            end if
        end if
        return cmd_status(table, svc_arg, plain)
    elif command == "start"
        return cmd_start(table, arg)
    elif command == "stop"
        return cmd_stop(table, arg)
    elif command == "restart"
        return cmd_restart(table, arg)
    elif command == "log"
        return cmd_log(table, arg)
    elif command == "reload"
        g_reload_requested = true
        return "reload initiated\n"
    elif command == "replace"
        // Optional --wait=N argument
        mut wait_seconds = 0
        if str.length(arg) > 0
            // Parse --wait=N
            if str.substring(arg, 0, 7) == "--wait="
                let val = str.substring(arg, 7, str.length(arg) - 7)
                wait_seconds = parse_replace_int_or(val, 0)
            else
                return "error: replace: unknown argument: " + arg + "\n"
            end if
        end if
        g_replace_requested = true
        g_replace_wait = wait_seconds
        return str.concat("replace queued (wait=", str.concat(int_to_str(wait_seconds), ")\n"))
    elif command == "halt"
        g_shutdown_request = shutdown.SHUT_HALT()
        return "halting\n"
    elif command == "reboot"
        g_shutdown_request = shutdown.SHUT_REBOOT()
        return "rebooting\n"
    elif command == "poweroff"
        g_shutdown_request = shutdown.SHUT_POWEROFF()
        return "powering off\n"
    elif command == "single"
        g_runlevel_request = 1   // RUNLEVEL_SINGLE
        return "transitioning to single-user\n"
    elif command == "multi"
        g_runlevel_request = 0   // RUNLEVEL_MULTI
        return "transitioning to multi-user\n"
    elif command == "multiuser"
        // Legacy alias for backward compatibility
        g_runlevel_request = 0
        return "transitioning to multi-user\n"
    elif command == "enable"
        return cmd_enable(arg)
    elif command == "disable"
        return cmd_disable(arg)
    elif command == "list"
        // Parse optional PLAIN modifier
        mut list_plain = 0
        if arg == "plain"
            list_plain = 1
        end if
        return cmd_list(table, list_plain)
    elif command == "version"
        return "zyginit " + version.VERSION() + "\n"
    elif command == "help"
        return cmd_help()
    end if

    return "error: unknown command: " + command + "\n"
end dispatch_command

// ============================================================================
// Command implementations
// ============================================================================

fn cmd_status(table: supervisor.ServiceTable, arg: string, plain: int): string
    let count = supervisor.service_count(table)

    if str.length(arg) > 0
        // Status of a single service — honor the plain flag from the caller
        let idx = supervisor.find_service(table, arg)
        if idx < 0
            return "error: unknown service: " + arg + "\n"
        end if
        return ui_render.ui_render_status_one(table, idx, plain)
    end if

    // Status of all services
    if count == 0
        return "no services loaded\n"
    end if

    // plain=1: no banner, no escapes; plain=0: banner + colors via daemon's g_mode
    return ui_render.ui_render_status(table, 1, plain)
end cmd_status

fn cmd_start(table: supervisor.ServiceTable, name: string): string
    if str.length(name) == 0
        return "error: usage: start <service>\n"
    end if

    let idx = supervisor.find_service(table, name)
    if idx < 0
        return "error: unknown service: " + name + "\n"
    end if

    let rt = supervisor.get_runtime(table, idx)
    let state = supervisor.rt_state(rt)

    if state == supervisor.STATE_RUNNING()
        return name + " is already running\n"
    end if

    let conflict_peer = supervisor.conflicting_running_peer(table, idx)
    if conflict_peer >= 0
        let other = supervisor.service_name_at(table, conflict_peer)
        return "error: cannot start " + name + ": conflicts with running service " + other + "\n"
    end if

    if supervisor.start_service(table, idx)
        return name + " started\n"
    end if

    return "error: failed to start " + name + "\n"
end cmd_start

fn cmd_stop(table: supervisor.ServiceTable, name: string): string
    if str.length(name) == 0
        return "error: usage: stop <service>\n"
    end if

    let idx = supervisor.find_service(table, name)
    if idx < 0
        return "error: unknown service: " + name + "\n"
    end if

    if supervisor.stop_service(table, idx)
        return name + " stopping\n"
    end if

    return name + " is not running\n"
end cmd_stop

fn cmd_restart(table: supervisor.ServiceTable, name: string): string
    if str.length(name) == 0
        return "error: usage: restart <service>\n"
    end if

    let idx = supervisor.find_service(table, name)
    if idx < 0
        return "error: unknown service: " + name + "\n"
    end if

    let rt = supervisor.get_runtime(table, idx)
    let state = supervisor.rt_state(rt)

    if state == supervisor.STATE_RUNNING()
        supervisor.stop_service(table, idx)
    end if

    // Note: actual restart happens via the event loop when the stop completes
    // and restart policy triggers. For immediate restart of a stopped service:
    if state != supervisor.STATE_RUNNING()
        if supervisor.start_service(table, idx)
            return name + " restarted\n"
        end if
        return "error: failed to restart " + name + "\n"
    end if

    return name + " stop initiated (will restart via policy)\n"
end cmd_restart

fn cmd_list(table: supervisor.ServiceTable, plain: int): string
    return ui_render.ui_render_list(table, plain)
end cmd_list

fn cmd_log(table: supervisor.ServiceTable, name: string): string
    if str.length(name) == 0
        return "error: usage: log <service>\n"
    end if

    let idx = supervisor.find_service(table, name)
    if idx < 0
        return "error: unknown service: " + name + "\n"
    end if

    return supervisor.get_service_log(name)
end cmd_log

fn cmd_enable(name: string): string
    if str.length(name) == 0
        return "error: usage: enable <service>\n"
    end if

    let config_dir = env.get_env_or("ZYGINIT_CONFIG_DIR", "/etc/zyginit")
    let toml_path = str.concat(str.concat(config_dir, "/"), str.concat(name, ".toml"))

    if not file.fileExists(toml_path)
        return "error: no service definition found: " + toml_path + "\n"
    end if

    let enabled_dir = str.concat(config_dir, "/enabled.d")

    if not dir.dir_exists(enabled_dir)
        if res.is_err(dir.create_dir(enabled_dir))
            return "error: cannot create " + enabled_dir + "\n"
        end if
    end if

    let link_path = str.concat(str.concat(enabled_dir, "/"), name)

    if file.fileExists(link_path)
        return name + " is already enabled\n"
    end if

    let target = str.concat("../", str.concat(name, ".toml"))
    let rc = zyginit_symlink(target, link_path)
    if rc < 0
        return "error: failed to create symlink for " + name + "\n"
    end if

    return name + " enabled\n"
end cmd_enable

fn cmd_disable(name: string): string
    if str.length(name) == 0
        return "error: usage: disable <service>\n"
    end if

    let config_dir = env.get_env_or("ZYGINIT_CONFIG_DIR", "/etc/zyginit")
    let enabled_dir = str.concat(config_dir, "/enabled.d")
    let link_path = str.concat(str.concat(enabled_dir, "/"), name)

    if not file.fileExists(link_path)
        return name + " is not enabled\n"
    end if

    if res.is_ok(file.deleteFile(link_path))
        return name + " disabled\n"
    end if

    return "error: failed to remove " + link_path + "\n"
end cmd_disable

fn cmd_help(): string
    return "commands: status [name], start <name>, stop <name>, restart <name>, enable <name>, disable <name>, reload, replace [--wait=N], halt, reboot, poweroff, single, multiuser, log <name>, list, version, help\n"
end cmd_help

// ============================================================================
// Local helper functions
// ============================================================================

// Convert an integer to a string
fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

// Local int parser for replace --wait=N. Negative numbers and non-numeric
// input both yield default_val. Empty string also yields default.
fn parse_replace_int_or(s: string, default_val: int): int
    let n = str.length(s)
    if n == 0
        return default_val
    end if
    mut result = 0
    mut i = 0
    while i < n
        let c = str.char_at(s, i)
        if c < '0' or c > '9'
            return default_val
        end if
        result = result * 10 + (c - '0')
        i = i + 1
    end while
    return result
end parse_replace_int_or

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: depgraph.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Dependency graph and topological sort for service boot order

******************************************************************************/

module depgraph

import config
import collections.hashmap as hashmap
import core.str
import core.option as opt

export
    type DepGraph

    fn MAX_SERVICES(): int
    fn MAX_DEPS(): int

    fn new_depgraph(): DepGraph
    fn add_service(graph: DepGraph, name: string): int
    fn add_dependency(graph: DepGraph, name: string, dep_name: string): bool
    fn build_graph(graph: DepGraph, services: [config.ServiceDef], count: int): bool
    fn topo_sort(graph: DepGraph, tiers: [string], tier_counts: [int], max_tiers: int): int
    fn has_cycle(graph: DepGraph): bool
    fn service_count(graph: DepGraph): int
    fn service_name_at(graph: DepGraph, idx: int): string
end export

// ============================================================================
// Constants
// ============================================================================

fn MAX_SERVICES(): int
    return 128
end MAX_SERVICES

fn MAX_DEPS(): int
    return 16
end MAX_DEPS

// ============================================================================
// DepGraph type
// ============================================================================

type DepGraph = struct
    // Service names indexed 0..count-1
    names: [string]
    count: int

    // Name to index lookup
    name_map: hashmap.HashMap[int]

    // Adjacency: flattened array, deps[i * MAX_DEPS + j] = index of dep j for service i
    deps: [int]
    dep_count: [int]

    // In-degree for topological sort
    in_degree: [int]
end DepGraph

fn new_depgraph(): DepGraph
    let max = MAX_SERVICES()
    let max_d = MAX_DEPS()

    let g = DepGraph{
        names: new [string](max),
        count: 0,
        name_map: hashmap.create[:int](0 - 1),
        deps: new [int](max * max_d),
        dep_count: new [int](max),
        in_degree: new [int](max)
    }

    // Initialize dep_count and in_degree to 0
    mut i = 0
    while i < max
        g.dep_count[i] = 0
        g.in_degree[i] = 0
        i = i + 1
    end while

    return g
end new_depgraph

// ============================================================================
// Graph construction
// ============================================================================

// Add a service node to the graph. Returns its index, or -1 if full.
fn add_service(graph: DepGraph, name: string): int
    // Check if already exists
    let existing: opt.Option[int] = graph.name_map.get(name)
    if opt.is_some(existing)
        return opt.unwrap(existing)
    end if

    if graph.count >= MAX_SERVICES()
        return 0 - 1
    end if

    let idx = graph.count
    graph.names[idx] = name
    graph.name_map.set(name, idx)
    graph.dep_count[idx] = 0
    graph.in_degree[idx] = 0
    graph.count = graph.count + 1

    return idx
end add_service

// Add a dependency edge: "name" depends on "dep_name".
// Both must already be in the graph. Returns true on success.
fn add_dependency(graph: DepGraph, name: string, dep_name: string): bool
    if not graph.name_map.has(name)
        return false
    end if
    if not graph.name_map.has(dep_name)
        return false
    end if

    let from_opt: opt.Option[int] = graph.name_map.get(name)
    let to_opt: opt.Option[int] = graph.name_map.get(dep_name)
    let from_idx = opt.unwrap(from_opt)
    let to_idx = opt.unwrap(to_opt)
    let dc = graph.dep_count[from_idx]

    if dc >= MAX_DEPS()
        return false
    end if

    // Check for duplicate edge
    let base = from_idx * MAX_DEPS()
    mut i = 0
    while i < dc
        if graph.deps[base + i] == to_idx
            return true
        end if
        i = i + 1
    end while

    // Add edge: from_idx depends on to_idx
    graph.deps[base + dc] = to_idx
    graph.dep_count[from_idx] = dc + 1

    // Increment in-degree of from_idx (it has one more dependency)
    graph.in_degree[from_idx] = graph.in_degree[from_idx] + 1

    return true
end add_dependency

// Build the dependency graph from an array of ServiceDefs.
// Returns true on success, false if a cycle is detected.
fn build_graph(graph: DepGraph, services: [config.ServiceDef], count: int): bool
    // First pass: add all service nodes
    mut i = 0
    while i < count
        let name = config.svc_name(services[i])
        if str.length(name) > 0
            add_service(graph, name)
        end if
        i = i + 1
    end while

    // Second pass: add dependency edges
    i = 0
    while i < count
        let name = config.svc_name(services[i])

        // Add "requires" edges
        let req = config.svc_requires(services[i])
        let req_count = config.svc_requires_count(services[i])
        mut j = 0
        while j < req_count
            let dep_name = req[j]
            if graph.name_map.has(dep_name)
                add_dependency(graph, name, dep_name)
            else
                println("depgraph: warning: " + name + " requires unknown service: " + dep_name)
            end if
            j = j + 1
        end while

        // Add "after" edges (ordering only, same graph treatment)
        let aft = config.svc_after(services[i])
        let aft_count = config.svc_after_count(services[i])
        j = 0
        while j < aft_count
            let dep_name = aft[j]
            if graph.name_map.has(dep_name)
                add_dependency(graph, name, dep_name)
            end if
            // Silently skip unknown "after" deps — they are soft ordering hints
            j = j + 1
        end while

        i = i + 1
    end while

    // Check for cycles
    if has_cycle(graph)
        println("depgraph: error: dependency cycle detected")
        return false
    end if

    return true
end build_graph

// ============================================================================
// Topological sort (Kahn's algorithm)
// ============================================================================

// Perform topological sort and group services into parallel tiers.
// Returns the number of tiers. Tiers are written into tiers[] as a flat
// array, with tier_counts[t] indicating how many services are in tier t.
// Services within a tier can start in parallel.
fn topo_sort(graph: DepGraph, tiers: [string], tier_counts: [int], max_tiers: int): int
    let n = graph.count

    if n == 0
        return 0
    end if

    // Copy in_degree to working array (preserve original)
    let work_degree = new [int](MAX_SERVICES())
    mut i = 0
    while i < n
        work_degree[i] = graph.in_degree[i]
        i = i + 1
    end while

    // Track which nodes have been placed
    let placed = new [bool](MAX_SERVICES())
    i = 0
    while i < n
        placed[i] = false
        i = i + 1
    end while

    mut total_placed = 0
    mut tier_idx = 0
    mut tier_offset = 0

    while total_placed < n and tier_idx < max_tiers
        // Find all nodes with in_degree == 0 that haven't been placed
        mut tier_size = 0

        i = 0
        while i < n
            if not placed[i] and work_degree[i] == 0
                tiers[tier_offset + tier_size] = graph.names[i]
                tier_size = tier_size + 1
                placed[i] = true
            end if
            i = i + 1
        end while

        if tier_size == 0
            // No progress — remaining nodes form a cycle
            break
        end if

        tier_counts[tier_idx] = tier_size

        // Decrement in_degree for all nodes that depend on placed nodes
        // For each placed node in this tier, find who depends on it
        mut t = 0
        while t < tier_size
            let placed_name = tiers[tier_offset + t]
            let placed_opt: opt.Option[int] = graph.name_map.get(placed_name)
            let placed_idx = opt.unwrap(placed_opt)

            // Scan all nodes to find those that depend on placed_idx
            i = 0
            while i < n
                if not placed[i]
                    let base = i * MAX_DEPS()
                    let dc = graph.dep_count[i]
                    mut d = 0
                    while d < dc
                        if graph.deps[base + d] == placed_idx
                            work_degree[i] = work_degree[i] - 1
                        end if
                        d = d + 1
                    end while
                end if
                i = i + 1
            end while

            t = t + 1
        end while

        total_placed = total_placed + tier_size
        tier_offset = tier_offset + tier_size
        tier_idx = tier_idx + 1
    end while

    if total_placed < n
        println("depgraph: error: cycle detected, could not place all services")
    end if

    return tier_idx
end topo_sort

// ============================================================================
// Cycle detection
// ============================================================================

// Check for cycles using iterative Kahn's — if we can't place all nodes,
// there's a cycle.
fn has_cycle(graph: DepGraph): bool
    let n = graph.count
    if n == 0
        return false
    end if

    let work_degree = new [int](MAX_SERVICES())
    mut i = 0
    while i < n
        work_degree[i] = graph.in_degree[i]
        i = i + 1
    end while

    // Queue-based Kahn's — just count how many we can place
    let queue = new [int](MAX_SERVICES())
    mut head = 0
    mut tail = 0

    // Enqueue all nodes with in_degree 0
    i = 0
    while i < n
        if work_degree[i] == 0
            queue[tail] = i
            tail = tail + 1
        end if
        i = i + 1
    end while

    mut placed = 0

    while head < tail
        let node = queue[head]
        head = head + 1
        placed = placed + 1

        // For each other node, if it depends on this node, decrement
        i = 0
        while i < n
            let base = i * MAX_DEPS()
            let dc = graph.dep_count[i]
            mut d = 0
            while d < dc
                if graph.deps[base + d] == node
                    work_degree[i] = work_degree[i] - 1
                    if work_degree[i] == 0
                        queue[tail] = i
                        tail = tail + 1
                    end if
                end if
                d = d + 1
            end while
            i = i + 1
        end while
    end while

    return placed < n
end has_cycle

// ============================================================================
// Accessors
// ============================================================================

fn service_count(graph: DepGraph): int
    return graph.count
end service_count

fn service_name_at(graph: DepGraph, idx: int): string
    if idx >= 0 and idx < graph.count
        return graph.names[idx]
    end if
    return ""
end service_name_at

end module
/*
 * helpers.c — Portable C helpers for zyginit
 *
 * Thin wrappers around POSIX functions that need:
 *   - const char* bridging for Reef FFI (which emits char*)
 *   - multi-step sequences grouped for atomicity (e.g. drop_privileges)
 *   - passwd/group lookups returning simple int values
 *
 * Compiled on both Linux and Hammerhead. On Hammerhead it is passed alongside
 * -lcontract; on Linux it is passed alongside contract_linux_stubs.o.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <string.h>
#include <time.h>
#include <utmpx.h>
#include <errno.h>
#include <sys/types.h>

#ifdef __sun
#include <sys/uadmin.h>
#include <stropts.h>
#endif

/* Wrapper for symlink() — avoids const char* vs char* conflict with Reef FFI */
int zyginit_symlink(char *target, char *linkpath) {
    return symlink(target, linkpath);
}

/* Wrapper for rename() — avoids const char* vs char* conflict with Reef FFI */
int zyginit_rename(char *oldpath, char *newpath) {
    return rename(oldpath, newpath);
}

/* Wrapper for unlink() — avoids const char* vs char* conflict with Reef FFI */
int zyginit_unlink(char *path) {
    return unlink(path);
}

/* Wrapper for fsync() — sys.fd does not expose fsync; the wrapper keeps
 * the FFI surface consistent with zyginit_rename / zyginit_unlink. */
int zyginit_fsync(int fd) {
    return fsync(fd);
}

/* Look up a user by name. Returns uid, or -1 if not found. */
int zyginit_getuid_by_name(char *name) {
    struct passwd *pw = getpwnam(name);
    if (pw == NULL) return -1;
    return (int)pw->pw_uid;
}

/* Look up a user's primary gid by name. Returns gid, or -1 if not found. */
int zyginit_getgid_by_username(char *name) {
    struct passwd *pw = getpwnam(name);
    if (pw == NULL) return -1;
    return (int)pw->pw_gid;
}

/* Look up a group by name. Returns gid, or -1 if not found. */
int zyginit_getgid_by_name(char *name) {
    struct group *gr = getgrnam(name);
    if (gr == NULL) return -1;
    return (int)gr->gr_gid;
}

/* Drop privileges: setgid, initgroups, setuid. Returns 0 on success, -1 on error. */
int zyginit_drop_privileges(char *username, int uid, int gid) {
    if (setgid(gid) != 0) return -1;
    if (initgroups(username, gid) != 0) return -1;
    if (setuid(uid) != 0) return -1;
    return 0;
}

/* Flush all dirty page-cache buffers to disk before shutdown. sync(2) is
 * POSIX and exists on both Linux and Hammerhead — no #ifdef needed.
 *
 * NOTE: sync(2) on illumos *schedules* writes; it does not wait for
 * completion. For ZFS with pending metadata changes (e.g. our
 * destroy_socket's unlink), use zyginit_fsync_path() to force a
 * synchronous commit. */
void zyginit_sync(void) {
    sync();
}

/* Run a shell command via system(3), waiting for completion. Used in
 * the shutdown path to force `zpool sync` and `umountall -l` before
 * uadmin so all pending ZFS metadata (especially destroy_socket's
 * unlink) is durably on disk. fsync alone isn't enough — illumos's
 * sync(2) is async and the kernel reboot races with the txg commit.
 *
 * Returns the command's exit status, or -1 if system() itself failed. */
int zyginit_run_cmd(char *cmd) {
    int rc = system(cmd);
    if (rc < 0) return -1;
    return rc;
}

/* fsync the file at the given path (or its parent dir if the path
 * itself doesn't exist). Forces ZFS txg commit for any pending changes
 * touching that path. Returns 0 on success, -1 on error.
 *
 * Used after destroy_socket's unlink(/var/run/zyginit.sock) to make
 * sure the unlink is on disk before the child process triggers
 * uadmin. Without it, the kernel reboot can race with the ZFS txg
 * commit — boot 2 then sees a stale socket file in /var/run, boot 2's
 * create_socket can't recover cleanly, and zygctl loses its socket. */
#include <fcntl.h>
#include <libgen.h>
int zyginit_fsync_path(char *path) {
    int fd;
    fd = open(path, O_RDONLY);
    if (fd < 0) {
        /* Path doesn't exist (probably just unlinked). fsync the parent
         * dir so the directory entry's removal is committed. */
        char buf[4096];
        char *parent;
        strncpy(buf, path, sizeof(buf) - 1);
        buf[sizeof(buf) - 1] = '\0';
        parent = dirname(buf);
        fd = open(parent, O_RDONLY);
        if (fd < 0) return -1;
    }
    int rc = fsync(fd);
    int saved = errno;
    close(fd);
    errno = saved;
    return rc;
}

/* Shutdown wrapper — uadmin(A_SHUTDOWN, fcn, 0). On Hammerhead this is the
 * primitive init uses to halt, reboot, or poweroff the system. fcn is one of:
 *   AD_HALT     (0) — stop scheduler, wait for operator
 *   AD_BOOT     (1) — reboot
 *   AD_POWEROFF (6) — ACPI/BMC chassis off
 * Returns 0 on success, -1 on error (errno set). On success, does not return
 * for AD_BOOT / AD_POWEROFF; for AD_HALT the kernel enters a halted state.
 * On Linux (dev build only) returns -1 unconditionally.
 */
#ifdef __sun
int zyginit_shutdown(int fcn) {
    return uadmin(A_SHUTDOWN, fcn, 0);
}
#else
int zyginit_shutdown(int fcn) { (void)fcn; return -1; }
#endif

/* Push the ldterm + ttcompat STREAMS modules onto an open fd so that
 * \n is translated to \r\n on output. Without this, zyginit's println
 * output to /dev/console (which has no autopush'd line discipline at
 * the time PID 1 first opens it) appears column-shifted relative to
 * kernel cmn_err writes. Returns 0 on success, -1 on any push error.
 * Linux build is a no-op (STREAMS doesn't exist there). */
#ifdef __sun
int zyginit_push_ldterm(int fd) {
    if (ioctl(fd, I_PUSH, "ldterm") < 0) return -1;
    if (ioctl(fd, I_PUSH, "ttcompat") < 0) return -1;
    return 0;
}
#else
int zyginit_push_ldterm(int fd) { (void)fd; return 0; }
#endif

/* Write a BOOT_TIME utmpx record. Standard illumos init does this so
 * who(1) -b and uptime(1) report the actual boot time. Returns 0 on
 * success, -1 on error. */
int zyginit_write_boot_utmpx(void) {
    struct utmpx ux;
    memset(&ux, 0, sizeof (ux));
    strncpy(ux.ut_user, "reboot", sizeof (ux.ut_user));
    strncpy(ux.ut_line, "system boot", sizeof (ux.ut_line));
    ux.ut_pid = 0;
    ux.ut_type = BOOT_TIME;
    (void) time(&ux.ut_tv.tv_sec);
    setutxent();
    if (pututxline(&ux) == NULL) { endutxent(); return -1; }
    endutxent();
    return 0;
}

/* Write a RUN_LVL utmpx record with the given level character (e.g.,
 * 'S' for single-user, '3' for multi-user). who(1) -r and runlevel(8)
 * read this. Returns 0 on success, -1 on error.
 *
 * Format matches what svc.startd's utmpx_set_runlevel() writes
 * (cmd/svc/startd/utmpx.c):
 *   ut_line = "run-level X" (where X is the level char)
 *   ut_exit.e_termination = new runlevel char
 *   ut_exit.e_exit = previous level (we use 0 — first transition)
 *   ut_type = RUN_LVL
 *   ut_id, ut_user, ut_pid = unused for run-level records
 *
 * Linux build is a no-op (RUN_LVL constant and the e_termination /
 * e_exit struct members don't exist in glibc's utmpx; this is a
 * Hammerhead-specific feature for who(1)/uptime(1) integration).
 */
#ifdef __sun
#include <stdio.h>
int zyginit_write_runlvl_utmpx(int level_char) {
    struct utmpx ux;
    struct utmpx *oup;
    char prev_level = '0';

    memset(&ux, 0, sizeof (ux));
    ux.ut_type = RUN_LVL;

    setutxent();
    /* For RUN_LVL/BOOT_TIME, getutxid matches on type only — use it
     * to find the existing record so pututxline updates rather than
     * appends. Without this, who(1) -r returns the FIRST record
     * (often stale) instead of the most-recent transition. */
    oup = getutxid(&ux);
    if (oup != NULL) {
        prev_level = oup->ut_exit.e_termination;
    }

    snprintf(ux.ut_line, sizeof (ux.ut_line), "run-level %c", (char)level_char);
    ux.ut_exit.e_termination = (char)level_char;
    ux.ut_exit.e_exit = prev_level;
    (void) time(&ux.ut_tv.tv_sec);

    if (pututxline(&ux) == NULL) { endutxent(); return -1; }
    endutxent();
    return 0;
}
#else
int zyginit_write_runlvl_utmpx(int level_char) { (void)level_char; return -1; }
#endif

/* Read the BOOT_TIME utmpx record's tv_sec value, used as the boot-id
 * sentinel for the live-replace state file. PID-1 in-place execve
 * preserves the same proc_t but the kernel does not preserve a "boot
 * id" anywhere obvious — utmpx BOOT_TIME survives because it lives in
 * /var/adm/utmpx, written by zyginit_write_boot_utmpx() at boot. A
 * real reboot writes a new BOOT_TIME with a different tv_sec, so
 * comparing against it lets the new zyginit detect a stale state file.
 *
 * Returns the BOOT_TIME tv_sec on success, or -1 if the file is not
 * readable, has no BOOT_TIME entry, or any utmpx call fails.
 *
 * NOTE: This function is no longer used by read_boot_time() in replace.reef
 * (replaced by zyginit_read_pid1_start below), but is retained here for
 * any future use (e.g., updating utmpx BOOT_TIME on detected reboot).
 */
int zyginit_read_boot_time(void) {
    struct utmpx *up;
    int result = -1;

    setutxent();
    while ((up = getutxent()) != NULL) {
        if (up->ut_type == BOOT_TIME) {
            result = (int) up->ut_tv.tv_sec;
            break;
        }
    }
    endutxent();
    return result;
}

/* Return CLOCK_MONOTONIC time in milliseconds as an int.
 * Used by ui.reef for elapsed-time stamps on tape rows.
 * Returns 0 on error (no caller needs error detail). */
int zyginit_monotonic_ms(void) {
    struct timespec ts;
    if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) return 0;
    return (int)((ts.tv_sec * 1000) + (ts.tv_nsec / 1000000));
}

/* Rolling tape backing store for ui.reef.
 *
 * Reef's module-level `new []` initializers compile to GNU statement
 * expressions, which are invalid in C static initializer context.
 * Using pre-allocated C static arrays avoids the limitation entirely.
 *
 * String slots (glyph/name/note) are owned copies (strdup'd). Reef GC
 * may collect the original strings before a deferred redraw (Task 6
 * ui_tick) reads them back, so we take ownership here.
 */
/* ZYGINIT_TAPE_SLOTS is the maximum physical tape buffer size.
 * The *active* tape height is computed at runtime by ui_detect_winsize()
 * (stored in g_tape_height, clamped to [4, 32]) so it adapts to the
 * terminal size.  The C buffer is sized to the maximum so the ring-buffer
 * logic can use any slot index 0..31 without bounds trouble; rows beyond
 * g_tape_height are simply never used. */
#define ZYGINIT_TAPE_SLOTS 32

static int   zyginit_tape_elapsed_buf[ZYGINIT_TAPE_SLOTS];
static char *zyginit_tape_glyph_buf[ZYGINIT_TAPE_SLOTS];
static char *zyginit_tape_name_buf[ZYGINIT_TAPE_SLOTS];
static char *zyginit_tape_note_buf[ZYGINIT_TAPE_SLOTS];
static int   zyginit_tape_active_buf[ZYGINIT_TAPE_SLOTS];

/* Return the number of tape slots. Single source of truth for ui.reef. */
int zyginit_tape_slots(void) {
    return ZYGINIT_TAPE_SLOTS;
}

void zyginit_tape_clear(void) {
    int i;
    for (i = 0; i < ZYGINIT_TAPE_SLOTS; i++) {
        zyginit_tape_elapsed_buf[i] = 0;
        free(zyginit_tape_glyph_buf[i]); zyginit_tape_glyph_buf[i] = NULL;
        free(zyginit_tape_name_buf[i]);  zyginit_tape_name_buf[i]  = NULL;
        free(zyginit_tape_note_buf[i]);  zyginit_tape_note_buf[i]  = NULL;
        zyginit_tape_active_buf[i] = 0;
    }
}

/* zyginit_tape_set: set all fields of a slot, including the active flag.
 * active: 0 = static, 1 = forward spinner (starting), 2 = reverse spinner (stopping). */
void zyginit_tape_set(int slot, int elapsed, char *glyph, char *name, char *note, int active) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return;
    zyginit_tape_elapsed_buf[slot] = elapsed;

    free(zyginit_tape_glyph_buf[slot]);
    zyginit_tape_glyph_buf[slot] = (glyph && glyph[0]) ? strdup(glyph) : NULL;

    free(zyginit_tape_name_buf[slot]);
    zyginit_tape_name_buf[slot]  = (name  && name[0])  ? strdup(name)  : NULL;

    free(zyginit_tape_note_buf[slot]);
    zyginit_tape_note_buf[slot]  = (note  && note[0])  ? strdup(note)  : NULL;

    zyginit_tape_active_buf[slot] = active;
}

int zyginit_tape_get_active(int slot) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return 0;
    return zyginit_tape_active_buf[slot];
}

void zyginit_tape_set_active(int slot, int active) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return;
    zyginit_tape_active_buf[slot] = active;
}

/* Update the glyph in place — used when a row transitions from active to terminal. */
void zyginit_tape_set_glyph(int slot, char *glyph) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return;
    free(zyginit_tape_glyph_buf[slot]);
    zyginit_tape_glyph_buf[slot] = (glyph && glyph[0]) ? strdup(glyph) : NULL;
}

/* Update the note in place. */
void zyginit_tape_set_note(int slot, char *note) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return;
    free(zyginit_tape_note_buf[slot]);
    zyginit_tape_note_buf[slot] = (note && note[0]) ? strdup(note) : NULL;
}

int   zyginit_tape_get_elapsed(int slot) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return 0;
    return zyginit_tape_elapsed_buf[slot];
}
char *zyginit_tape_get_glyph(int slot) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return (char *)"";
    return zyginit_tape_glyph_buf[slot] ? zyginit_tape_glyph_buf[slot] : (char *)"";
}
char *zyginit_tape_get_name(int slot) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return (char *)"";
    return zyginit_tape_name_buf[slot]  ? zyginit_tape_name_buf[slot]  : (char *)"";
}
char *zyginit_tape_get_note(int slot) {
    if (slot < 0 || slot >= ZYGINIT_TAPE_SLOTS) return (char *)"";
    return zyginit_tape_note_buf[slot]  ? zyginit_tape_note_buf[slot]  : (char *)"";
}

/* zyginit_isatty: thin wrapper around isatty(3) so Reef FFI sees an int
 * return. Returns 1 if fd is a terminal, 0 otherwise. */
int zyginit_isatty(int fd) {
    return isatty(fd) ? 1 : 0;
}

/* zyginit_esc_str: returns a static string containing only the ESC
 * character (0x1b). Used by ui.reef to build ANSI/SGR escape sequences
 * at runtime, since the Reef lexer does not support \x or octal string
 * escapes — only \n, \t, \r, \\, \", \$. */
const char *zyginit_esc_str(void) {
    static const char buf[2] = { '\x1b', '\0' };
    return buf;
}

/* Read terminal size from fd (usually 1 = stdout = /dev/console).
 * Stores rows in out_rows[0] and cols in out_cols[0].
 * Returns 0 on success, -1 on failure.
 *
 * On Hammerhead /dev/console is a STREAMS tty that supports TIOCGWINSZ
 * via the tem driver's GWINSZ ioctl. On Linux (dev build) this works
 * against any real tty but falls back to -1 when not a tty (e.g. in
 * integration tests), which is fine — ui_detect_winsize uses the
 * ZYGINIT_FORCE_80x25 path for test stability. */
#include <sys/ioctl.h>
#include <sys/termios.h>   /* struct winsize, TIOCGWINSZ — illumos puts these here,
                              not in <sys/ioctl.h> like Linux does */
int zyginit_get_winsize(int fd, int *out_rows, int *out_cols) {
    struct winsize ws;
    if (ioctl(fd, TIOCGWINSZ, &ws) != 0) return -1;
    *out_rows = ws.ws_row;
    *out_cols = ws.ws_col;
    return 0;
}

/* Resolve a symlink (or any path) to its canonical absolute form via
 * realpath(3). The resolved path is stored in a module-level static buffer
 * to avoid heap allocation (Reef FFI owns the returned string only for the
 * lifetime of the current call — callers must copy before calling again).
 * Returns the resolved path on success, or "" on any error (dangling link,
 * ENOENT, EACCES, etc.). Used by config.reef's scan_enabled_dir to validate
 * that enabled.d/ symlinks actually target a path inside services/. */
static char zyginit_readlink_buf[4096];
char *zyginit_readlink_resolved(char *path) {
    char *resolved = realpath(path, zyginit_readlink_buf);
    return resolved ? resolved : (char *)"";
}

/* Read PID 1's process start time, used as the boot-id sentinel for
 * live-replace. Survives execve (proc_t preserved) but changes on real
 * reboot (new PID 1). Returns the start time as an int, or -1 on error.
 *
 * Linux: /proc/1/stat field 22 (start_time in jiffies-since-boot)
 * illumos: /proc/1/psinfo pr_start.tv_sec (Unix timestamp)
 *
 * This correctly handles the case where zyginit_write_boot_utmpx() is
 * called at startup by the new zyginit after execve — pututxline updates
 * rather than appends the BOOT_TIME record, so utmpx BOOT_TIME is
 * unreliable as a boot-id sentinel after live replace. /proc/1/start
 * is stable across execve but changes on real reboot (new PID 1 starts
 * with a fresh proc_t), making it the correct sentinel.
 */
#ifdef __sun
#include <procfs.h>
int zyginit_read_pid1_start(void) {
    int fd;
    psinfo_t psinfo;
    fd = open("/proc/1/psinfo", O_RDONLY);
    if (fd < 0) return -1;
    if (read(fd, &psinfo, sizeof(psinfo)) != (ssize_t)sizeof(psinfo)) {
        close(fd);
        return -1;
    }
    close(fd);
    return (int) psinfo.pr_start.tv_sec;
}
#else
int zyginit_read_pid1_start(void) {
    int fd;
    char buf[1024];
    int n;
    fd = open("/proc/1/stat", O_RDONLY);
    if (fd < 0) return -1;
    n = read(fd, buf, sizeof(buf) - 1);
    close(fd);
    if (n <= 0) return -1;
    buf[n] = '\0';

    /* /proc/<pid>/stat format: "pid (comm) state ppid pgrp ..."
     * Field 22 (1-indexed) is starttime. Parse by skipping past the
     * comm field's trailing ')', then count whitespace-separated fields.
     * Skip to the LAST ')' to handle commas/parens in comm. */
    char *p = strrchr(buf, ')');
    if (p == NULL) return -1;
    p++;  /* skip past ')' */

    /* Now we're at " state ppid pgrp ... starttime ..."
     * Field numbering: pid=1, comm=2, state=3, ppid=4, ..., starttime=22.
     * We have already consumed fields 1 and 2 (pid + comm). We need to
     * skip fields 3..21 (19 fields) to land on field 22 (starttime).
     * Loop while field < 21 skips 19 tokens (field=2..20, 19 iterations). */
    int field = 2;  /* we just consumed pid + comm = fields 1,2 */
    while (*p && field < 21) {
        while (*p == ' ') p++;
        while (*p && *p != ' ') p++;
        field++;
    }
    while (*p == ' ') p++;
    if (*p == '\0') return -1;

    long starttime = 0;
    while (*p >= '0' && *p <= '9') {
        starttime = starttime * 10 + (*p - '0');
        p++;
    }
    return (int) starttime;
}
#endif

/* Run a shell command with a timeout. Returns:
 *   command's exit code on normal completion (0 = success),
 *   -2 if timeout exceeded (child killed),
 *   -3 if command binary not found (exit 127 from sh),
 *   -4 on other exec/fork failure.
 * Runs via /bin/sh -c so $PATH lookup works. */
#include <sys/wait.h>
#include <signal.h>
int run_command_with_timeout(char *cmd, int timeout_sec) {
    pid_t pid = fork();
    if (pid < 0) return -4;
    if (pid == 0) {
        /* child */
        execl("/bin/sh", "sh", "-c", cmd, (char *)0);
        _exit(127);   /* exec failed */
    }
    /* parent: poll waitpid until exit or timeout */
    time_t deadline = time(0) + timeout_sec;
    int status;
    for (;;) {
        pid_t r = waitpid(pid, &status, WNOHANG);
        if (r == pid) {
            if (WIFEXITED(status)) {
                int ec = WEXITSTATUS(status);
                if (ec == 127) return -3;   /* exec failed in child */
                return ec;
            }
            return -4;   /* signaled */
        }
        if (r < 0) return -4;
        if (time(0) >= deadline) {
            kill(pid, SIGKILL);
            waitpid(pid, &status, 0);
            return -2;
        }
        struct timespec ts = { 0, 50 * 1000 * 1000 };   /* 50ms poll */
        nanosleep(&ts, 0);
    }
}
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: main.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Main entry point — event loop for zyginit init daemon

******************************************************************************/

module zyginit

import config
import depgraph
import contract
import supervisor
import ctlsocket
import shutdown
import replace
import ui
import io.dir
import sys.process as process
import sys.signal as signal
import sys.poll as poll
import sys.fd as fd
import time.time as time
import time.clock as clock
import sys.env as env
import sys.args as args
import core.str
import version

// FFI: helpers.c — push ldterm + ttcompat onto a fd's STREAMS stack.
// On /dev/console without these modules, \n is LF only (no CR), so
// userspace println output is column-shifted relative to kernel writes.
extern "C" fn zyginit_push_ldterm(fd: int): int

// FFI: write boot/runlevel utmpx records so who -b and who -r report
// correctly. Standard illumos init does these — without them uptime
// shows stale data and `who -r` returns nothing useful.
extern "C" fn zyginit_write_boot_utmpx(): int
extern "C" fn zyginit_write_runlvl_utmpx(level_char: int): int

// FFI: run a shell command synchronously via libc system(). Used in
// the shutdown path to force `zpool sync` + `umountall -l` so ZFS
// metadata (esp. our socket-file unlink) is durably committed to
// disk before the child process triggers uadmin's reboot.
extern "C" fn zyginit_run_cmd(cmd: string): int

// FFI: fsync a path's parent directory (or the path itself if it is a
// directory). Used to durably flush directory-entry changes (unlink,
// rename) without needing a writeable fd on the target path.
extern "C" fn zyginit_fsync_path(path: string): int

// FFI: unlink(2) wrapper. Returns 0 on success, -1 on error.
extern "C" fn zyginit_unlink(path: string): int

// ============================================================================
// Constants
// ============================================================================

fn SOCKET_PATH(): string
    return env.get_env_or("ZYGINIT_SOCKET", "/var/run/zyginit.sock")
end SOCKET_PATH

fn CONFIG_DIR(): string
    return env.get_env_or("ZYGINIT_CONFIG_DIR", "/etc/zyginit")
end CONFIG_DIR

fn MAX_SERVICES(): int
    return 128
end MAX_SERVICES

// Grace period (ms) between the last boot tier completing and painting the
// final boot card. Daemons that fork successfully (entering RUNNING) but
// die immediately produce a contract-empty event that may arrive 10-100ms
// after the tier settle loop declares them RUNNING. Without this window,
// ui_boot_complete would see "0 failed" while the failure log appears
// moments later. 1000ms is enough headroom for the fastest-failing daemons
// observed in production (acpihpd, ~30ms post-fork) with a comfortable
// safety margin. Adjust here if needed.
fn BOOT_SETTLE_MS(): int
    return 1000
end BOOT_SETTLE_MS

// Returns true when running as PID 1 (i.e., actual init). When not PID 1,
// the integration-test path: SIGTERM → stop services → normal exit
// (no uadmin call). When PID 1, shutdown must call uadmin or the kernel
// panics.
fn is_pid_1(): bool
    return process.getpid() == 1
end is_pid_1

// When the kernel exec()s init, fd 0/1/2 are NOT pre-opened — there's no
// stdin/stdout/stderr inherited from a shell. Without this fixup, every
// println() silently drops, and pipe()/socket() syscalls allocate the
// lowest-available fds (0, 1, 2), corrupting the implicit assumption
// elsewhere in the code that fd 0/1/2 == stdin/stdout/stderr. That's
// what bricked our first PID-1 boot attempt: setup_signal_pipe()'s
// `if pipe_fds[0] <= 0` check tripped on a legitimate fd 0, returned
// false, main() returned early via the FATAL path, kernel re-exec'd in
// a tight loop.
//
// Open /dev/console RDWR, dup it onto 0/1/2, close the original.
// Returns true on success, false if /dev/console couldn't be opened.
fn setup_pid1_console(): bool
    // O_NOCTTY (0x800 on Hammerhead) — open /dev/console for read/write
    // BUT do not claim it as zyginit's controlling terminal. Without
    // this, the console-login service's ttymon (which runs in a new
    // session via setsid) cannot claim /dev/console as its own
    // controlling tty, exits 1 silently, and the local-console login
    // restart-loops into MAINTENANCE.
    let cfd = fd.fd_open("/dev/console", fd.O_RDWR() + 0x800, 0)
    if cfd < 0
        return false
    end if

    // Push ldterm + ttcompat onto the STREAMS stack. Standard illumos
    // boot has /sbin/autopush -f /etc/iu.ap run via inittab :sysinit:
    // before svc.startd opens /dev/console; that auto-pushes these
    // modules per the wc-driver entry. zyginit is PID 1, so there's
    // no userland path to autopush before we open /dev/console — push
    // explicitly. Without this, \n is LF-only and println output is
    // column-shifted vs kernel cmn_err writes (visible alignment mess
    // during early boot before kernel device init quiets down).
    let _push = zyginit_push_ldterm(cfd)

    let _0 = fd.fd_dup2(cfd, 0)
    let _1 = fd.fd_dup2(cfd, 1)
    let _2 = fd.fd_dup2(cfd, 2)
    if cfd > 2
        let _ = fd.fd_close(cfd)
    end if
    return true
end setup_pid1_console

// ============================================================================
// Signal self-pipe
// ============================================================================

// Signal self-pipe fds — written to by signal handler polling,
// read by main event loop to wake up from poll().
mut g_signal_pipe_read: int = 0 - 1
mut g_signal_pipe_write: int = 0 - 1

// Requested shutdown type (set by signal handler or socket command).
// SHUT_NONE = no shutdown in progress.
mut g_shutdown_type: int = 0   // = shutdown.SHUT_NONE() — but can't call fn in init

// Human-readable shutdown reason for ui_shutdown_start ("halt", "reboot", "poweroff").
// Set when g_shutdown_type is set.
mut g_shutdown_reason: string = "halt"

// Current runlevel — 0 = MULTI (default), 1 = SINGLE.
// Initialized at boot from kernel boot args (-s for single-user) and
// changed at runtime by runlevel-transition socket commands. Services
// with [runlevel] mode = "always" run in both; "single"-only services
// run only when g_runlevel == SINGLE; "multi"-only services run only
// when g_runlevel == MULTI.
mut g_runlevel: int = 0    // 0 = MULTI (matches config.RUNLEVEL_MULTI())

// Monotonic timestamp (ms) when the boot sequence began — used to compute
// total boot elapsed time for ui_boot_complete.
mut g_boot_start_ms: int = 0

// PID-1 process start time, used as the boot-id sentinel for live-replace.
// Read from /proc/1/stat (Linux) or /proc/1/psinfo (illumos) at startup.
// Survives execve (same proc_t) but changes on real reboot (new PID 1).
// state.toml is only accepted if its boot_time field matches this value,
// ensuring a stale state file from a previous boot is rejected.
// Initialized to -1; set during main() before recover_state.
mut g_boot_time: int = 0 - 1

fn RUNLEVEL_MULTI(): int  return 0  end RUNLEVEL_MULTI
fn RUNLEVEL_SINGLE(): int return 1  end RUNLEVEL_SINGLE

// Returns true if a service should be in the active set for the given
// runlevel. "always" services run in any runlevel; "single"-mode runs
// only when target == SINGLE; "multi"-mode runs only when target == MULTI.
fn service_in_runlevel(svc_def: config.ServiceDef, target_runlevel: int): bool
    let mode = config.svc_runlevel_mode(svc_def)
    if mode == config.RUNLEVEL_ALWAYS()
        return true
    elif mode == config.RUNLEVEL_SINGLE()
        return target_runlevel == RUNLEVEL_SINGLE()
    else
        // mode == config.RUNLEVEL_MULTI()
        return target_runlevel == RUNLEVEL_MULTI()
    end if
end service_in_runlevel

// Parse boot args for runlevel selection. Returns RUNLEVEL_SINGLE if
// the kernel passed -s, otherwise RUNLEVEL_MULTI. Hammerhead's
// /boot/loader.conf may set boot-args="-v -m verbose -s" to request
// single-user; the kernel forwards these to /sbin/init's argv.
fn parse_boot_runlevel(): int
    if args.has_flag("s")
        return RUNLEVEL_SINGLE()
    end if
    return RUNLEVEL_MULTI()
end parse_boot_runlevel

// Set up the self-pipe for signal notification.
// Returns true on success.
fn setup_signal_pipe(): bool
    let pipe_fds = fd.fd_pipe()
    if pipe_fds[0] <= 0
        println("zyginit: failed to create signal pipe")
        return false
    end if

    g_signal_pipe_read = pipe_fds[0]
    g_signal_pipe_write = pipe_fds[1]

    // Make both ends non-blocking
    fd.fd_set_nonblocking(g_signal_pipe_read, true)
    fd.fd_set_nonblocking(g_signal_pipe_write, true)

    return true
end setup_signal_pipe

// Write a byte to the signal pipe to wake up poll().
proc signal_pipe_notify()
    fd.fd_write(g_signal_pipe_write, "1")
end signal_pipe_notify

// Drain the signal pipe (read all pending bytes).
proc signal_pipe_drain()
    fd.fd_read(g_signal_pipe_read, 64)
end signal_pipe_drain

// ============================================================================
// Service startup by tier
// ============================================================================

// Start all services in boot order (tier by tier).
// Services within a tier are started in sequence; the tier as a whole must
// settle (oneshots reach STOPPED, daemons reach RUNNING) before we move on
// to tier N+1. Without this wait, downstream services start before their
// upstream `requires` are satisfied — e.g. rpcbind in tier 4 looking for
// the loopback datalink before network in tier 3 has created it. There's
// a per-tier deadline (60 seconds = 120 × 500ms) so a single broken
// oneshot doesn't wedge the boot forever; we warn and proceed if the
// tier hasn't settled by then.
proc start_services_by_tier(table: supervisor.ServiceTable,
                            tiers: [string], tier_counts: [int],
                            num_tiers: int)
    mut tier_offset = 0
    mut tier = 0

    while tier < num_tiers
        let tier_size = tier_counts[tier]
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("zyginit: starting tier " + int_to_str(tier) +
                    " (" + int_to_str(tier_size) + " services)")
        end if
        ui.ui_tier_start(tier)

        // Phase A: kick off all services in this tier whose [runlevel] mode
        // matches the current g_runlevel and which aren't already running.
        // Skipping the running check makes this safe to reuse from
        // transition_runlevel (only newly-active services get started).
        mut j = 0
        while j < tier_size
            let name = tiers[tier_offset + j]
            let idx = supervisor.find_service(table, name)
            if idx >= 0
                let rt = supervisor.get_runtime(table, idx)
                let def = supervisor.rt_def(rt)
                let state = supervisor.rt_state(rt)
                if service_in_runlevel(def, g_runlevel) and state == supervisor.STATE_WAITING()
                    supervisor.start_service(table, idx)
                elif not service_in_runlevel(def, g_runlevel) and state == supervisor.STATE_WAITING()
                    supervisor.mark_runlevel_filtered(table, idx)
                end if
            else
                println("zyginit: warning: service in boot order not in table: " + name)
            end if
            j = j + 1
        end while

        // Phase B: wait for the tier to settle. Acceptable terminal states:
        //   - oneshot:  STATE_STOPPED (success or failure both count as
        //               "settled" — we proceed regardless to surface the
        //               cascade rather than wedging boot)
        //   - daemon:   STATE_RUNNING (or terminal MAINTENANCE/FAILED)
        // Transitional states (STATE_STARTING, etc.) keep us waiting.
        mut waiting = 1
        mut waits = 0
        while waiting > 0 and waits < 120
            waiting = 0
            mut k = 0
            while k < tier_size
                let name2 = tiers[tier_offset + k]
                let idx2 = supervisor.find_service(table, name2)
                if idx2 >= 0
                    let rt = supervisor.get_runtime(table, idx2)
                    let state = supervisor.rt_state(rt)
                    let def2 = supervisor.rt_def(rt)
                    let svc_type = config.svc_type(def2)

                    // Skip services not in active runlevel — they were
                    // never started so we shouldn't wait for them.
                    if not service_in_runlevel(def2, g_runlevel)
                        k = k + 1
                        continue
                    end if

                    mut settled = false
                    if svc_type == config.SERVICE_TYPE_ONESHOT()
                        if state == supervisor.STATE_STOPPED() or
                           state == supervisor.STATE_FAILED() or
                           state == supervisor.STATE_MAINTENANCE()
                            settled = true
                        end if
                    else
                        // Daemon (or transient): RUNNING is the goal;
                        // MAINTENANCE/FAILED also counts as settled so we
                        // surface the failure rather than block boot.
                        if state == supervisor.STATE_RUNNING() or
                           state == supervisor.STATE_FAILED() or
                           state == supervisor.STATE_MAINTENANCE()
                            settled = true
                        end if
                    end if

                    if not settled
                        waiting = waiting + 1
                    end if
                end if
                k = k + 1
            end while

            if waiting > 0
                clock.sleep_millis(500)
                // Process exits and contract events while we wait so state
                // can actually transition.
                reap_children(table)
                supervisor.check_stop_timeouts(table)
                // Advance the UI tick so spinner animation continues while
                // we are blocked in this settle-wait loop.
                ui.ui_tick()
                waits = waits + 1
            end if
        end while

        if waiting > 0
            if ui.ui_mode() == ui.MODE_PLAIN()
                println("zyginit: warning: tier " + int_to_str(tier) +
                        " did not settle within 60s (" + int_to_str(waiting) +
                        " services still transitioning); proceeding anyway")
            end if
        end if

        ui.ui_tier_done(tier)
        tier_offset = tier_offset + tier_size
        tier = tier + 1
    end while
end start_services_by_tier

// Warn (once, at boot) about conflict targets that name a non-existent service.
proc warn_unknown_conflicts(table: supervisor.ServiceTable, def: config.ServiceDef)
    let conf = config.svc_conflicts(def)
    let n = config.svc_conflicts_count(def)
    mut k = 0
    while k < n
        if supervisor.find_service(table, conf[k]) < 0
            println("zyginit: warning: " + config.svc_name(def) +
                    " conflicts with unknown service: " + conf[k])
        end if
        k = k + 1
    end while
end warn_unknown_conflicts

// Boot-only pre-flight: for every pair of services that are both active in the
// current runlevel and declared mutually exclusive, mark BOTH failed before any
// fork. zyginit never auto-picks a winner. Runtime conflicts (zygctl start,
// runlevel transitions) are handled by the guard in supervisor.start_service.
proc resolve_conflicts(table: supervisor.ServiceTable)
    let n = supervisor.service_count(table)
    mut i = 0
    while i < n
        let rt_i = supervisor.get_runtime(table, i)
        let def_i = supervisor.rt_def(rt_i)
        if supervisor.rt_state(rt_i) == supervisor.STATE_WAITING() and service_in_runlevel(def_i, g_runlevel)
            warn_unknown_conflicts(table, def_i)
            mut j = i + 1
            while j < n
                let rt_j = supervisor.get_runtime(table, j)
                let def_j = supervisor.rt_def(rt_j)
                if supervisor.rt_state(rt_j) == supervisor.STATE_WAITING() and service_in_runlevel(def_j, g_runlevel) and supervisor.conflicts_with(table, i, j)
                    let name_i = config.svc_name(def_i)
                    let name_j = config.svc_name(def_j)
                    supervisor.mark_conflict_failed(table, i, name_j)
                    supervisor.mark_conflict_failed(table, j, name_i)
                    if ui.ui_mode() == ui.MODE_PLAIN()
                        println("zyginit: conflict: " + name_i + " and " + name_j +
                                " are mutually exclusive; failing both")
                    end if
                end if
                j = j + 1
            end while
        end if
        i = i + 1
    end while
end resolve_conflicts

// ============================================================================
// Apply state from a previous zyginit instance (live replace).
// For each entry in `recovered`, locate the service in `table` and
// patch in runtime fields via supervisor.adopt_runtime. Services in
// state.toml that are no longer in enabled.d/ get their contract
// abandoned but their member processes left running. After patching,
// run the post-recovery empty-contract check to catch services that
// exited during the exec gap.
proc apply_recovered_state(table: supervisor.ServiceTable,
                           recovered: replace.RecoveredState)
    if replace.rs_is_empty(recovered)
        return
    end if

    let n = replace.rs_count(recovered)
    println("zyginit: replace: applying " + int_to_str(n) + " recovered services")

    mut i = 0
    while i < n
        let rs = replace.rs_service(recovered, i)
        let name = replace.svc_name(rs)
        let ctid = replace.svc_contract_id(rs)

        let idx = supervisor.find_service(table, name)
        if idx < 0
            // Operator removed the symlink between old start and replace.
            // Don't kill — abandon the contract; member processes
            // continue running unsupervised.
            let abrc = contract.abandon_contract(ctid)
            println("zyginit: replace: orphaned " + name +
                    " (no longer enabled, contract " + int_to_str(ctid) +
                    " abandon rc=" + int_to_str(abrc) + ")")
        else
            // Patch runtime fields. PID is unknown (not serialized); contract
            // path is sufficient for supervision.
            supervisor.adopt_runtime(table, idx, supervisor.STATE_RUNNING(),
                0 - 1, ctid,
                replace.svc_restart_count(rs),
                replace.svc_last_exit_code(rs),
                replace.svc_last_start_time(rs))

            println("zyginit: replace: re-attached " + name +
                    " (ctid=" + int_to_str(ctid) +
                    ", restarts=" + int_to_str(replace.svc_restart_count(rs)) + ")")

            // Idempotency: did the contract go empty during the exec gap?
            if contract.is_contract_empty(ctid)
                println("zyginit: replace: " + name +
                        " contract empty post-recovery, applying restart policy")
                supervisor.handle_contract_event(table, ctid, 0 - 1)
            end if
        end if

        i = i + 1
    end while
end apply_recovered_state

// Operator-driven live replace. Triggered by zygctl replace; the
// socket handler sets g_replace_requested and we pick it up on the
// next event-loop tick. After this returns successfully, control
// transfers to the new /sbin/init process; this fn does not return
// on success.
//
// On precondition failure or any I/O error before exec, we log and
// return; the caller clears the flag and continues normally.
proc replace_self(table: supervisor.ServiceTable, boot_time: int, wait_seconds: int)
    println("zyginit: replace: requested (wait=" + int_to_str(wait_seconds) + ")")

    // Pre-condition check, with optional wait window.
    // Drive reap_children + check_stop_timeouts inside the wait loop so
    // transient services (STARTING, STOPPING, WAITING) can actually
    // transition to stable states. Mirrors the pattern in
    // start_services_by_tier and shutdown_services.
    mut elapsed_ms = 0
    let wait_ms = wait_seconds * 1000
    mut report = replace.check_preconditions(table)
    while str.length(report) > 0 and elapsed_ms < wait_ms
        clock.sleep_millis(500)
        reap_children(table)
        supervisor.check_stop_timeouts(table)
        elapsed_ms = elapsed_ms + 500
        report = replace.check_preconditions(table)
    end while

    if str.length(report) > 0
        println("zyginit: replace: blocked: " + report)
        return
    end if

    // Serialize state to /var/run/zyginit/state.toml.
    if not replace.serialize_state(table, boot_time)
        println("zyginit: replace: state serialization failed; aborting")
        return
    end if
    println("zyginit: replace: state written to " + replace.STATE_FILE_PATH())

    // Unlink the socket. Proceed even on failure — new zyginit will
    // overwrite. zyginit_fsync_path falls back to fsync'ing the parent
    // dir when the path itself doesn't exist, which is exactly what we
    // want after unlink — the rename of the directory entry gets
    // committed.
    let sock_path = SOCKET_PATH()
    let urc = zyginit_unlink(sock_path)
    if urc != 0
        println("zyginit: replace: warning: socket unlink failed (rc=" + int_to_str(urc) + ")")
    end if
    let _ = zyginit_fsync_path(sock_path)

    // Exec /sbin/init in place. argv[0] = the binary path; argv has
    // one element. process.process_exec replaces the current process
    // image; on success it does not return.
    let target = "/sbin/init"
    let argv = new [string](1)
    argv[0] = target

    println("zyginit: replace: execve " + target)
    let _ = process.process_exec(target, argv)

    // If we reach here, exec failed. We have already written state.toml
    // and unlinked the socket — recovery requires reboot.
    println("zyginit: replace: FATAL: execve returned (kernel could not load " + target + ")")
end replace_self

// Configuration reload (SIGHUP)
// ============================================================================

// Re-scan enabled.d/, compare with current table, add new / disable removed.
// V1: does not detect in-place config changes to existing services.
proc reload_services(table: supervisor.ServiceTable)
    let config_dir = CONFIG_DIR()
    let max = MAX_SERVICES()

    // Re-scan enabled services
    let new_services = new [config.ServiceDef](max)
    let raw_count = config.load_enabled_services(config_dir, new_services, max)

    // If services/ disappeared during a live reload, bail out — do not
    // disable all running services as a side-effect.
    if raw_count < 0
        println("zyginit: reload: services/ directory missing — reload aborted")
        return
    end if
    let new_count = raw_count

    // Build a list of names currently in the new scan
    let new_names = new [string](max)
    mut ni = 0
    while ni < new_count
        new_names[ni] = config.svc_name(new_services[ni])
        ni = ni + 1
    end while

    // Pass 1: Disable services that are no longer enabled
    let current_count = supervisor.service_count(table)
    mut ci = 0
    while ci < current_count
        let rt = supervisor.get_runtime(table, ci)
        let state = supervisor.rt_state(rt)

        // Skip already-disabled services
        if state != supervisor.STATE_DISABLED()
            let name = config.svc_name(supervisor.rt_def(rt))
            mut found = false

            mut j = 0
            while j < new_count
                if new_names[j] == name
                    found = true
                    break
                end if
                j = j + 1
            end while

            if not found
                println("zyginit: reload: disabling " + name)
                supervisor.disable_service(table, ci)
            end if
        end if

        ci = ci + 1
    end while

    // Pass 2: Add new services that are not in the table
    mut added = 0
    mut si = 0
    while si < new_count
        let name = new_names[si]
        let idx = supervisor.find_service(table, name)

        if idx < 0
            // New service — add and start
            let new_idx = supervisor.add_service(table, new_services[si])
            if new_idx >= 0
                println("zyginit: reload: adding " + name)
                supervisor.start_service(table, new_idx)
                added = added + 1
            end if
        elif supervisor.rt_state(supervisor.get_runtime(table, idx)) == supervisor.STATE_DISABLED()
            // Was disabled, re-enable and start
            println("zyginit: reload: re-enabling " + name)
            supervisor.start_service(table, idx)
            added = added + 1
        end if

        si = si + 1
    end while

    println("zyginit: reload complete (" + int_to_str(added) + " services added/re-enabled)")
end reload_services

// ============================================================================
// Signal handling
// ============================================================================

// Check for received signals and handle them.
// Returns false if zyginit should shut down.
fn handle_signals(table: supervisor.ServiceTable): bool
    // SIGTERM / SIGINT — initiate shutdown
    if signal.signal_received(signal.SIGTERM()) or signal.signal_received(signal.SIGINT())
        println("zyginit: received shutdown signal")
        // Default: halt (conservative). Socket commands can override.
        if g_shutdown_type == shutdown.SHUT_NONE()
            g_shutdown_type = shutdown.SHUT_HALT()
            g_shutdown_reason = "halt"
        end if
        return false
    end if

    // SIGHUP — reload config
    if signal.signal_received(signal.SIGHUP())
        println("zyginit: SIGHUP received, reloading configuration")
        reload_services(table)
    end if

    // SIGCHLD — reap exited children
    if signal.signal_received(signal.SIGCHLD())
        reap_children(table)
    end if

    return true
end handle_signals

// Reap all exited children and dispatch to supervisor.
proc reap_children(table: supervisor.ServiceTable)
    // Try to reap children in a loop until no more have exited.
    // We scan the service table for running PIDs and try_wait each.
    let count = supervisor.service_count(table)
    mut i = 0
    while i < count
        let rt = supervisor.get_runtime(table, i)
        let pid = supervisor.rt_pid(rt)
        if pid > 0 and supervisor.rt_state(rt) >= 2
            if process.process_try_wait(pid)
                let exit_code = process.process_exit_code()
                let ctid = supervisor.rt_contract_id(rt)
                if ctid >= 0
                    supervisor.handle_contract_event(table, ctid, exit_code)
                else
                    supervisor.handle_child_exit(table, pid, exit_code)
                end if
            end if
        end if
        i = i + 1
    end while

    // Catch-all: reap any other zombie children we don't track in the
    // service table. Daemonize-style services may leave intermediate
    // PIDs as zombies after the parent exits and we cleared rt.pid;
    // PID 1 must reap them or they accumulate as <defunct> entries.
    mut zpid = process.process_wait_any_nohang()
    while zpid > 0
        zpid = process.process_wait_any_nohang()
    end while
end reap_children

// ============================================================================
// Contract event handling
// ============================================================================

// Read and dispatch contract events from the bundle fd.
proc handle_contract_events(table: supervisor.ServiceTable, bundle_fd: int)
    let out_ctid = new [int](1)
    let out_type = new [int](1)

    // Read events in a loop until no more are available
    while contract.read_event(bundle_fd, out_ctid, out_type)
        let ctid = out_ctid[0]
        let evtype = out_type[0]

        // CT_PR_EV_EMPTY (1) = all processes in contract exited
        if evtype == contract.CT_PR_EV_EMPTY()
            supervisor.handle_contract_event(table, ctid, 0 - 1)
            contract.abandon_contract(ctid)
        end if
    end while
end handle_contract_events

// ============================================================================
// Shutdown
// ============================================================================

// Stop all services in reverse tier order.
// - Daemons in RUNNING: stop via contract SIGTERM (existing stop_service path).
// - Oneshots in STOPPED with a declared exec.stop: run the stop command.
// - Oneshots without stop: skip.
proc shutdown_services(table: supervisor.ServiceTable,
                       tiers: [string], tier_counts: [int], num_tiers: int)
    println("zyginit: stopping all services...")

    // Compute cumulative offsets per tier so we can scan each tier's slice.
    let offsets = new [int](num_tiers)
    mut off = 0
    mut i = 0
    while i < num_tiers
        offsets[i] = off
        off = off + tier_counts[i]
        i = i + 1
    end while

    // Walk tiers in reverse.
    mut tier = num_tiers - 1
    while tier >= 0
        let tier_off = offsets[tier]
        let tier_sz = tier_counts[tier]
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("zyginit: shutting down tier " + int_to_str(tier) +
                    " (" + int_to_str(tier_sz) + " services)")
        end if

        mut j = 0
        while j < tier_sz
            let name = tiers[tier_off + j]
            let idx = supervisor.find_service(table, name)
            if idx >= 0
                let rt = supervisor.get_runtime(table, idx)
                let state = supervisor.rt_state(rt)
                if state == supervisor.STATE_RUNNING()
                    // Running daemon: issue contract stop.
                    supervisor.stop_service(table, idx)
                elif state == supervisor.STATE_STOPPED()
                    // Oneshot that already exited: run its stop if declared.
                    let _ = supervisor.stop_oneshot(table, idx)
                end if
            end if
            j = j + 1
        end while

        // Drain phase: the stop-issuing j-loop above ran to completion before
        // we get here. We now wait for daemons in STATE_STOPPING to reach
        // STATE_STOPPED. KEEP THIS SEPARATE FROM THE STOP-ISSUING LOOP — merging
        // them would risk re-issuing stops to services that are merely waiting
        // to exit.
        //
        // Between tiers: wait for daemons in this tier to reach STOPPED
        // so we don't teardown upstream deps while downstream is still alive.
        // Loop with a short sleep until all RUNNING in this tier are gone,
        // with a safety deadline of 30 seconds (60 x 500ms).
        mut remaining = 1
        mut waits = 0
        while remaining > 0 and waits < 60
            remaining = 0
            mut k = 0
            while k < tier_sz
                let name2 = tiers[tier_off + k]
                let idx2 = supervisor.find_service(table, name2)
                if idx2 >= 0
                    let rt2 = supervisor.get_runtime(table, idx2)
                    if supervisor.rt_state(rt2) == supervisor.STATE_STOPPING()
                        remaining = remaining + 1
                    end if
                end if
                k = k + 1
            end while
            if remaining > 0
                clock.sleep_millis(500)
                // Also reap any child exits that happened during the wait,
                // and escalate stop timeouts to SIGKILL if configured.
                reap_children(table)
                supervisor.check_stop_timeouts(table)
                // Advance the UI tick so spinner animation continues while
                // we are blocked in this shutdown drain-wait loop.
                ui.ui_tick()
                waits = waits + 1
            end if
        end while

        if remaining > 0
            if ui.ui_mode() == ui.MODE_PLAIN()
                println("zyginit: tier " + int_to_str(tier) +
                        " shutdown timed out with " + int_to_str(remaining) +
                        " services still STOPPING; proceeding anyway")
            end if
        end if

        tier = tier - 1
    end while

    if ui.ui_mode() == ui.MODE_PLAIN()
        println("zyginit: all service tiers stopped")
    end if
end shutdown_services

// ============================================================================
// Runlevel transitions (zygctl single / zygctl multi)
// ============================================================================

// Transition the system from current g_runlevel to target_level. Called
// from the main event loop when ctlsocket.runlevel_requested() returns a
// non-sentinel value. Stops services no longer in the active set
// (reverse tier order) and starts services newly in the active set
// (forward tier order). Updates g_runlevel and writes a RUN_LVL utmpx
// record so who(1) -r reports the new level.
proc transition_runlevel(table: supervisor.ServiceTable,
                         tiers: [string], tier_counts: [int],
                         num_tiers: int, target_level: int)
    if target_level == g_runlevel
        println("zyginit: already in requested runlevel, ignoring")
        return
    end if

    let lvl_name = "multi"
    if target_level == RUNLEVEL_SINGLE()
        let lvl_name = "single"
    end if
    println("zyginit: transitioning to " + lvl_name + "-user mode")

    // Compute cumulative offsets per tier (reused for both passes).
    let offsets = new [int](num_tiers)
    mut off = 0
    mut i = 0
    while i < num_tiers
        offsets[i] = off
        off = off + tier_counts[i]
        i = i + 1
    end while

    // Pass 1: Stop services NOT in the new active set, reverse tier order.
    mut tier = num_tiers - 1
    while tier >= 0
        let tier_off = offsets[tier]
        let tier_sz = tier_counts[tier]
        mut j = 0
        while j < tier_sz
            let name = tiers[tier_off + j]
            let idx = supervisor.find_service(table, name)
            if idx >= 0
                let rt = supervisor.get_runtime(table, idx)
                let def = supervisor.rt_def(rt)
                if not service_in_runlevel(def, target_level)
                    let state = supervisor.rt_state(rt)
                    if state == supervisor.STATE_RUNNING()
                        supervisor.stop_service(table, idx)
                    end if
                end if
            end if
            j = j + 1
        end while

        // Drain: wait for STOPPING services in this tier to reach STOPPED.
        mut remaining = 1
        mut waits = 0
        while remaining > 0 and waits < 60
            remaining = 0
            mut k = 0
            while k < tier_sz
                let n2 = tiers[tier_off + k]
                let i2 = supervisor.find_service(table, n2)
                if i2 >= 0
                    let r2 = supervisor.get_runtime(table, i2)
                    if supervisor.rt_state(r2) == supervisor.STATE_STOPPING()
                        remaining = remaining + 1
                    end if
                end if
                k = k + 1
            end while
            if remaining > 0
                clock.sleep_millis(500)
                reap_children(table)
                supervisor.check_stop_timeouts(table)
                waits = waits + 1
            end if
        end while

        tier = tier - 1
    end while

    // Update g_runlevel BEFORE starting new services, so service_in_runlevel
    // checks during start phase use the new level.
    g_runlevel = target_level

    // Pass 2: Start services newly in the active set, forward tier order.
    // Reuses start_services_by_tier's per-tier kick + settle pattern by
    // simply calling it; it already filters by g_runlevel and skips
    // anything currently RUNNING.
    start_services_by_tier(table, tiers, tier_counts, num_tiers)

    // Write RUN_LVL utmpx record.
    if is_pid_1()
        if target_level == RUNLEVEL_SINGLE()
            let _ = zyginit_write_runlvl_utmpx(83)   // 'S'
        else
            let _ = zyginit_write_runlvl_utmpx(51)   // '3'
        end if
    end if

    println("zyginit: transition to " + lvl_name + "-user mode complete")
end transition_runlevel

// ============================================================================
// Main entry point
// ============================================================================

proc main()
    // --ui-demo <scenario>: run a canned UI scenario for snapshot testing.
    if args.has_flag("ui-demo")
        let scenario = args.get_flag_value("ui-demo")
        let demo_mode = ui.detect_rich_mode()
        ui.ui_init(demo_mode)
        // Detect window size so demo uses real terminal dimensions.
        // ZYGINIT_FORCE_80x25=1 in ui_tests.sh overrides this for
        // snapshot stability.
        ui.ui_detect_winsize()
        process.exit_now(ui.ui_demo(scenario))
    end if

    // Version short-circuit — ONLY when NOT PID 1. A human checking the version
    // always runs from a shell (getpid() != 1). This MUST be gated on
    // not is_pid_1(): when the kernel exec()s init as PID 1 it passes boot-args
    // like `-v` (verbose) and `-m verbose`. Treating `-v` as "print version and
    // exit" in the PID-1 case would make init return from main(), and the
    // kernel would re-exec init in a tight loop. For shell invocations,
    // `-v`/`-V`/`--version` all print the version and exit before any setup.
    // See bugs/archive/004-... (the `-v` foot-gun).
    if not is_pid_1() and (args.has_flag("version") or args.has_flag("V") or args.has_flag("v"))
        println("zyginit " + version.VERSION())
        return
    end if

    // Non-PID-1 supervisor runs exist ONLY for integration testing. On a
    // running host a real zyginit owns PID 1; a stray `zyginit ...` from a
    // shell must not spin up a second supervisor — it would bind (and clobber)
    // the control socket, load services, and enter the event loop, silently
    // breaking zygctl control of the live system. Require an explicit opt-in
    // flag so a bare `zyginit ...` on a production host is inert. See bug 004.
    if not is_pid_1() and not args.has_flag("supervisor-test")
        println("zyginit: refusing to run as a non-PID-1 supervisor without --supervisor-test")
        println("zyginit: a live zyginit already owns PID 1 on a running system;")
        println("zyginit: a second instance would clobber " + SOCKET_PATH())
        println("zyginit: to print the version use: zyginit --version")
        return
    end if

    // PID-1 fd setup MUST run before any println — when the kernel exec()s
    // init, stdin/stdout/stderr are not preopened. See setup_pid1_console
    // for the full explanation.
    if is_pid_1()
        let _ = setup_pid1_console()
    end if

    // Children inherit TERM from us. Set it to match Hammerhead's
    // kernel tem (framebuffer console). Services that need a different
    // TERM can override via their [exec].environment in TOML.
    if is_pid_1()
        let _ = env.set_env("TERM", "sun-color")
    end if

    // Initialize UI renderer. Must happen before any ui_event_* calls.
    // detect_rich_mode_for_main returns MODE_PLAIN when not PID 1 or when
    // stdout is not a terminal (integration tests set ZYGINIT_NO_UI=1).
    let rich_mode = ui.detect_rich_mode_for_main()
    ui.ui_init(rich_mode)

    // Detect terminal size. Must run after setup_pid1_console() (so fd 1 is
    // /dev/console) and after ui_init (so g_mode is set for future redraws).
    // On Linux dev builds or when stdout is a pipe, TIOCGWINSZ returns -1
    // and ui_detect_winsize falls back to 80x25 defaults.
    ui.ui_detect_winsize()

    if ui.ui_mode() == ui.MODE_PLAIN()
        println("zyginit v" + version.VERSION() + " starting")
        if is_pid_1()
            println("zyginit: running as PID 1 (init mode)")
        else
            println("zyginit: running as PID " + int_to_str(process.getpid()) + " (non-init mode)")
        end if
    end if

    // Determine boot runlevel from kernel-passed args. -s in boot-args
    // selects single-user mode; otherwise multi-user. Stored in g_runlevel.
    g_runlevel = parse_boot_runlevel()
    if ui.ui_mode() == ui.MODE_PLAIN()
        if g_runlevel == RUNLEVEL_SINGLE()
            println("zyginit: booting into single-user mode (-s in boot args)")
        else
            println("zyginit: booting into multi-user mode")
        end if
    end if

    // Write BOOT_TIME and RUN_LVL utmpx records so who(1) -b/-r and
    // uptime(1) report this boot. Best-effort; non-fatal on failure
    // (e.g., /var/adm/utmpx doesn't yet exist on a freshly-installed
    // BE — filesystem service will create the dir, this gets caught
    // by our utmpd service later or admin can touch the file).
    if is_pid_1()
        let _ = zyginit_write_boot_utmpx()
        // 'S' = 83, '3' = 51 (ASCII). Pass as int to the FFI helper.
        if g_runlevel == RUNLEVEL_SINGLE()
            let _ = zyginit_write_runlvl_utmpx(83)
        else
            let _ = zyginit_write_runlvl_utmpx(51)
        end if
    end if

    // Cache PID 1's process start time as the boot-id sentinel for
    // live-replace. /proc/1/start survives execve (same proc_t) but
    // changes on real reboot (new PID 1). utmpx BOOT_TIME was used
    // previously but pututxline updates rather than appends, so the
    // new zyginit overwrites the original timestamp at startup,
    // defeating the staleness check.
    if is_pid_1()
        g_boot_time = replace.read_boot_time()
        if g_boot_time < 0
            // Fallback: use time_now(). This degrades the staleness
            // check (a real reboot might collide if seconds-resolution
            // happens to repeat), but it's better than refusing all
            // replaces.
            g_boot_time = time.time_now()
            println("zyginit: warning: /proc/1/start read failed; using time_now() = " + int_to_str(g_boot_time))
        end if
    else
        // Non-PID-1 (supervisor mode for testing): stamp a fresh value.
        g_boot_time = time.time_now()
    end if

    // ---- Phase 1: Load service definitions ----

    let services = new [config.ServiceDef](MAX_SERVICES())
    let svc_count = config.load_enabled_services(CONFIG_DIR(), services, MAX_SERVICES())

    if svc_count < 0
        println("zyginit: FATAL: cannot proceed without services/ directory")
        println("zyginit: entering idle loop (boot from recovery medium to run migrate-layout.sh)")
        // svc_count is treated as 0 from here — the event loop will run
        // with no services, keeping the system accessible via the socket
        // (e.g., single-user shell via boot args or recovery medium).
    elif ui.ui_mode() == ui.MODE_PLAIN()
        if svc_count == 0
            println("zyginit: no enabled services found in " + CONFIG_DIR())
            println("zyginit: nothing to do, entering idle loop")
        else
            println("zyginit: loaded " + int_to_str(svc_count) + " services")
        end if
    end if

    // Clamp negative sentinel to 0 — all downstream code uses svc_count
    // as a loop bound or comparison; -1 would cause incorrect behavior.
    mut svc_count_clamped = svc_count
    if svc_count_clamped < 0
        svc_count_clamped = 0
    end if

    // ---- Phase 2: Build dependency graph ----

    let graph = depgraph.new_depgraph()
    let graph_ok = depgraph.build_graph(graph, services, svc_count_clamped)

    if not graph_ok
        println("zyginit: FATAL: dependency cycle detected, cannot boot")
        return
    end if

    let tiers = new [string](256)
    let tier_counts = new [int](32)
    let num_tiers = depgraph.topo_sort(graph, tiers, tier_counts, 32)

    if ui.ui_mode() == ui.MODE_PLAIN()
        println("zyginit: boot order has " + int_to_str(num_tiers) + " tiers")
    end if

    // ---- Create log directory ----

    let log_path = supervisor.log_dir()
    if not dir.dir_exists(log_path)
        dir.create_dir_all(log_path)
    end if

    // ---- Phase 3: Create service table ----

    let table = supervisor.new_service_table(MAX_SERVICES())

    mut i = 0
    while i < svc_count_clamped
        supervisor.add_service(table, services[i])
        i = i + 1
    end while

    // ---- Phase 3.5: Apply state from previous zyginit (live replace) ----
    //
    // If state.toml exists and is fresh (boot_time matches), the new
    // zyginit was just exec'd from a `zygctl replace` — re-attach
    // running services to their existing process contracts. Otherwise
    // recover_state returns an empty RecoveredState and we proceed
    // as a normal fresh boot.

    let recovered = replace.recover_state(g_boot_time)
    if not replace.rs_is_empty(recovered)
        apply_recovered_state(table, recovered)
    end if

    // ---- Phase 4: Set up signal handling ----

    signal.signal_init()
    signal.signal_handle(signal.SIGCHLD())
    signal.signal_handle(signal.SIGTERM())
    signal.signal_handle(signal.SIGINT())
    signal.signal_handle(signal.SIGHUP())
    signal.signal_ignore(signal.SIGPIPE())

    if not setup_signal_pipe()
        println("zyginit: FATAL: could not create signal pipe")
        return
    end if

    // ---- Phase 5: Open event sources ----

    // Contract bundle fd (will be -1 on Linux — that's expected)
    let bundle_fd = contract.open_bundle()

    // Unix domain socket for zygctl communication
    let socket_fd = ctlsocket.create_socket(SOCKET_PATH())

    // If we could not own the control socket AND we're not PID 1, a live
    // zyginit already holds it — create_socket refuses to clobber a socket a
    // server is actively listening on (see bug 004). A non-PID-1 instance with
    // no control socket is useless and must not linger, so exit cleanly. PID 1
    // keeps running even without a control socket: losing zygctl is far better
    // than halting init.
    if socket_fd < 0 and not is_pid_1()
        println("zyginit: control socket unavailable (a live server owns it); exiting")
        return
    end if

    // ---- Phase 6: Start services ----

    if svc_count_clamped > 0
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("")
            println("zyginit: starting services...")
        end if
        mut runlevel_name = "multi-user"
        if g_runlevel == RUNLEVEL_SINGLE()
            runlevel_name = "single-user"
        end if
        g_boot_start_ms = ui.zyginit_monotonic_ms()
        ui.ui_boot_start(svc_count_clamped, num_tiers, runlevel_name)
        resolve_conflicts(table)
        start_services_by_tier(table, tiers, tier_counts, num_tiers)

        // ---- Boot settle period ----
        // Drain contract/socket events for BOOT_SETTLE_MS() before painting
        // the final card. Daemons that fork successfully (enter RUNNING) but
        // die immediately produce a contract-empty event ~10-100ms after the
        // tier loop declares them settled. Without this window,
        // ui_boot_complete would show "0 failed" while the failure log
        // appears moments later.
        let settle_until = ui.zyginit_monotonic_ms() + BOOT_SETTLE_MS()
        while ui.zyginit_monotonic_ms() < settle_until
            // 200ms slices keep the spinner animation smooth and give
            // poll() a chance to return early on real contract events.
            let settle_ok = poll_once(table, bundle_fd, socket_fd, 200)
            if not settle_ok
                // Shutdown signal during settle — bail before the card.
                break
            end if
        end while

        let boot_elapsed = ui.zyginit_monotonic_ms() - g_boot_start_ms
        let boot_stats = build_boot_stats(table, boot_elapsed)
        ui.ui_boot_complete(boot_stats)
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("")
        end if
    end if

    // ---- Phase 7: Main event loop ----

    if ui.ui_mode() == ui.MODE_PLAIN()
        println("zyginit: entering event loop")
    end if
    mut running = true

    while running
        // Core poll iteration: signals, contract events, socket accept,
        // child reaping, stop-timeout checks, UI tick — 1 second timeout.
        running = poll_once(table, bundle_fd, socket_fd, 1000)
        if not running
            break
        end if

        // Check for reload requested via socket
        if ctlsocket.reload_requested()
            ctlsocket.clear_reload_flag()
            println("zyginit: reload requested via socket")
            reload_services(table)
        end if

        // Check for replace requested via socket
        if ctlsocket.replace_requested()
            let wait = ctlsocket.replace_wait_seconds()
            ctlsocket.clear_replace_flag()
            replace_self(table, g_boot_time, wait)
            // If replace_self exec'd successfully, we never get here.
            // If it returned, log and continue running normally.
        end if

        // Check for shutdown requested via socket (halt/reboot/poweroff)
        let req = ctlsocket.shutdown_requested()
        if req != 0
            ctlsocket.clear_shutdown_request()
            g_shutdown_type = req
            g_shutdown_reason = shutdown_type_to_reason(req)
            running = false
            println("zyginit: shutdown requested via socket (type " + int_to_str(req) + ")")
        end if

        // Check for runlevel transition requested via socket (single/multi)
        let rl_req = ctlsocket.runlevel_requested()
        if rl_req >= 0
            ctlsocket.clear_runlevel_request()
            transition_runlevel(table, tiers, tier_counts, num_tiers, rl_req)
        end if

        // Periodic restart-delay check (complements check_stop_timeouts
        // already called inside poll_once).
        supervisor.check_restart_delays(table)
    end while

    // ---- Shutdown ----

    if ui.ui_mode() == ui.MODE_PLAIN()
        println("")
    end if
    ui.ui_shutdown_start(g_shutdown_reason)
    let shutdown_start_ms = ui.zyginit_monotonic_ms()
    shutdown_services(table, tiers, tier_counts, num_tiers)
    let shutdown_elapsed_ms = ui.zyginit_monotonic_ms() - shutdown_start_ms
    ui.ui_shutdown_complete(g_shutdown_reason, shutdown_elapsed_ms)

    // Clean up
    if g_signal_pipe_read >= 0
        fd.fd_close(g_signal_pipe_read)
        fd.fd_close(g_signal_pipe_write)
    end if

    if bundle_fd >= 0
        fd.fd_close(bundle_fd)
    end if

    if socket_fd >= 0
        ctlsocket.destroy_socket(SOCKET_PATH(), socket_fd)
    end if

    println("zyginit: shutdown complete")

    // As PID 1, we MUST NOT return normally — kernel panics on "init died".
    // Call sync() then uadmin() based on the requested shutdown type.
    if is_pid_1()
        mut shut_type = g_shutdown_type
        if shut_type == shutdown.SHUT_NONE()
            shut_type = shutdown.SHUT_HALT()   // defensive default
        end if

        println("zyginit: sync()")
        shutdown.do_sync()

        // Force ZFS to commit all pending transactions to disk. illumos
        // sync(2) just *schedules* writes; ZFS may delay the txg commit
        // until its periodic flush. The kernel reboot in uadmin's
        // mdboot races with that commit — without this explicit
        // synchronous sync, the next boot can see stale state (e.g.,
        // an unlinked socket file appearing back). This is a data
        // integrity concern beyond the socket file: any pending writes
        // to root could be lost.
        println("zyginit: zpool sync (force ZFS metadata commit)")
        let _zsync = zyginit_run_cmd("/sbin/zpool sync 2>/dev/null")

        // Best-effort unmount of non-root local filesystems. Mirrors
        // svc.startd's do_uadmin sequence (cmd/svc/startd/graph.c).
        // For our setup this is mostly a no-op since everything is on
        // root, but it doesn't hurt and matches the canonical pattern.
        println("zyginit: umountall -l (best-effort)")
        let _umt = zyginit_run_cmd("/sbin/umountall -l 2>/dev/null")

        // One more sync after the umounts.
        shutdown.do_sync()

        let fcn = shutdown.to_ad_code(shut_type)
        println("zyginit: uadmin(A_SHUTDOWN, " + int_to_str(fcn) + ", 0)")

        // Fork a child to call uadmin. uadmin from PID 1 hits the kernel's
        // restart_init path: it marks PID 1 as exiting (releases vm,
        // closes fds, etc), and although uadmin's killall() spares the
        // calling process, init's death races with mdboot — the kernel
        // re-execs /sbin/init via restart_init() before mdboot's actual
        // hardware reset takes effect. Net result: init "restarts" but
        // the kernel never reboots; old child processes survive as
        // orphans of the new init, producing the cascading port-22-in-use
        // and stale-socket symptoms we observed (uptime stays at the
        // original boot, while PID 1 STIME advances). svc.startd avoids
        // this by being a regular non-PID-1 process; we mirror that here
        // by forking a child that does the actual syscall.
        let child_pid = process.process_fork()
        if child_pid == 0
            // CHILD: do the uadmin call. Tiny pause so the parent's
            // println above flushes to console before we vanish.
            clock.sleep_millis(100)
            let _ = shutdown.do_shutdown(fcn)
            // Should not reach here — mdboot is supposed to reset the
            // hardware. If it does return, exit so we don't keep running.
            process.exit_now(0)
        end if

        // PARENT (PID 1): infinite sleep — the child's uadmin will reset
        // the kernel within milliseconds. We MUST NOT return from main()
        // here because restart_init would re-exec us into a partial state.
        while true
            clock.sleep_seconds(3600)
        end while
    end if
    // Non-PID-1 path falls through and returns from main() normally.
end main

// ============================================================================
// Helpers
// ============================================================================

// Run one poll iteration: add fds, wait timeout_ms, drain signal pipe,
// process signals, dispatch contract events, reap children, advance UI tick.
// Returns false if a shutdown signal was received and the caller should
// exit its loop (g_shutdown_type is set by handle_signals before returning).
fn poll_once(table: supervisor.ServiceTable, bundle_fd: int, socket_fd: int,
             timeout_ms: int): bool
    poll.poll_clear()

    let sig_idx = poll.poll_add(g_signal_pipe_read, poll.POLLIN())

    mut bundle_idx = 0 - 1
    if bundle_fd >= 0
        bundle_idx = poll.poll_add(bundle_fd, poll.POLLIN())
    end if

    mut sock_idx = 0 - 1
    if socket_fd >= 0
        sock_idx = poll.poll_add(socket_fd, poll.POLLIN())
    end if

    let ready = poll.poll_wait(timeout_ms)

    ui.ui_tick()

    if ready > 0 and poll.poll_readable(sig_idx)
        signal_pipe_drain()
    end if

    let ok = handle_signals(table)

    if ready > 0 and bundle_idx >= 0 and poll.poll_readable(bundle_idx)
        handle_contract_events(table, bundle_fd)
    end if

    if ready > 0 and sock_idx >= 0 and poll.poll_readable(sock_idx)
        ctlsocket.handle_client(socket_fd, table)
    end if

    supervisor.check_stop_timeouts(table)
    reap_children(table)

    return ok
end poll_once

// Convert an internal shutdown type to a human-readable reason string for the UI.
fn shutdown_type_to_reason(shut_type: int): string
    if shut_type == shutdown.SHUT_REBOOT()
        return "reboot"
    elif shut_type == shutdown.SHUT_POWEROFF()
        return "poweroff"
    end if
    return "halt"
end shutdown_type_to_reason

// Build a BootStats struct from the service table.
// boot_elapsed_ms: wall time from boot start to now (computed by caller).
fn build_boot_stats(table: supervisor.ServiceTable, boot_elapsed_ms: int): ui.BootStats
    let count = supervisor.service_count(table)
    mut online = 0
    mut failed = 0
    mut skipped = 0
    mut i = 0
    while i < count
        let rt = supervisor.get_runtime(table, i)
        let st = supervisor.rt_state(rt)
        if st == supervisor.STATE_RUNNING()
            online = online + 1
        end if
        if st == supervisor.STATE_STOPPED()
            if supervisor.rt_last_exit_code(rt) == 0
                online = online + 1
            end if
        end if
        if st == supervisor.STATE_FAILED() or st == supervisor.STATE_MAINTENANCE()
            failed = failed + 1
        end if
        if st == supervisor.STATE_SKIPPED()
            skipped = skipped + 1
        end if
        i = i + 1
    end while
    let slow = new [string](3)
    return ui.BootStats{
        elapsed_ms: boot_elapsed_ms,
        online: online,
        failed: failed,
        skipped: skipped,
        slowest: slow,
        slowest_count: 0
    }
end build_boot_stats

fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: replace.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Live-replace state-file handoff (operator-driven PID-1 upgrade)

******************************************************************************/

// Live-replace operator flow: zygctl replace -> old zyginit serializes
// runtime state to /var/run/zyginit/state.toml, execs /sbin/init in
// place; new zyginit reads state.toml, validates boot_time matches
// current utmpx BOOT_TIME (else stale across a real reboot), and
// rebuilds the contract_map / runtime fields in supervisor.ServiceTable.
//
// PID-1 in-place execve preserves proc_t.p_ct_process at the kernel
// level, so contract ownership survives automatically — no
// ct_ctl_adopt call is needed. This module owns userspace bookkeeping.

module replace

import config
import supervisor
import io.file
import sys.fd as fd
import sys.env as sysenv
import core.str
import core.result as res
import encoding.toml
import time.time as time

export
    type RecoveredService
    type RecoveredState

    // Accessors — RecoveredState
    fn rs_count(s: RecoveredState): int
    fn rs_service(s: RecoveredState, idx: int): RecoveredService
    fn rs_boot_time(s: RecoveredState): int
    fn rs_is_empty(s: RecoveredState): bool

    // Accessors — RecoveredService
    fn svc_name(rs: RecoveredService): string
    fn svc_contract_id(rs: RecoveredService): int
    fn svc_restart_count(rs: RecoveredService): int
    fn svc_last_start_time(rs: RecoveredService): int
    fn svc_last_exit_code(rs: RecoveredService): int

    // Outgoing flow — write state, return true on success
    fn serialize_state(table: supervisor.ServiceTable, boot_time: int): bool

    // Incoming flow — read state file. Returns an empty RecoveredState
    // if the file is missing, corrupt, or has a mismatched boot_time.
    fn recover_state(current_boot_time: int): RecoveredState

    // Pre-condition check. Returns "" if all services are stable, else
    // a comma-separated "name:state" list suitable for logging.
    fn check_preconditions(table: supervisor.ServiceTable): string

    // FFI for boot-time sentinel (helpers.c)
    fn read_boot_time(): int

    // Constants
    fn STATE_FILE_PATH(): string
    fn STATE_TMP_PATH(): string
    fn STATE_DIR(): string
end export

// FFI — implemented in helpers.c
extern "C" fn zyginit_read_boot_time(): int
extern "C" fn zyginit_read_pid1_start(): int
extern "C" fn zyginit_fsync_path(path: string): int

// FFI — POSIX wrappers from helpers.c
// Direct extern "C" for rename/unlink/fsync would conflict with system
// headers' const char* declarations. Use zyginit_* wrappers (same pattern
// as zyginit_symlink).
extern "C" fn zyginit_rename(oldpath: string, newpath: string): int
extern "C" fn zyginit_unlink(path: string): int
extern "C" fn zyginit_fsync(fd: int): int

// Returns PID 1's process start time, used as the boot-id sentinel.
// Survives execve (proc_t preserved) but changes on real reboot.
// Returns -1 if /proc/1/{stat,psinfo} can't be read.
//
// NOTE: utmpx BOOT_TIME was used previously but pututxline updates rather
// than appends the existing record, so the new zyginit overwrites the
// original timestamp at startup, defeating the staleness check.
fn read_boot_time(): int
    return zyginit_read_pid1_start()
end read_boot_time

// File-system layout. Keep grouped here so a future tmpfs migration
// only edits one place.
fn STATE_DIR(): string
    return sysenv.get_env_or("ZYGINIT_RUN_DIR", "/var/run/zyginit")
end STATE_DIR

fn STATE_FILE_PATH(): string
    return str.concat(STATE_DIR(), "/state.toml")
end STATE_FILE_PATH

fn STATE_TMP_PATH(): string
    return str.concat(STATE_DIR(), "/state.toml.tmp")
end STATE_TMP_PATH

// ============================================================================
// Types
// ============================================================================

type RecoveredService = struct
    name: string
    contract_id: int
    restart_count: int
    last_start_time: int
    last_exit_code: int
end RecoveredService

type RecoveredState = struct
    boot_time: int
    services: [RecoveredService]
    count: int
end RecoveredState

fn new_recovered_state(): RecoveredState
    return RecoveredState{
        boot_time: 0 - 1,
        services: new [RecoveredService](0),
        count: 0
    }
end new_recovered_state

// ============================================================================
// Accessors
// ============================================================================

fn rs_count(s: RecoveredState): int
    return s.count
end rs_count

fn rs_service(s: RecoveredState, idx: int): RecoveredService
    return s.services[idx]
end rs_service

fn rs_boot_time(s: RecoveredState): int
    return s.boot_time
end rs_boot_time

fn rs_is_empty(s: RecoveredState): bool
    return s.count == 0
end rs_is_empty

fn svc_name(rs: RecoveredService): string
    return rs.name
end svc_name

fn svc_contract_id(rs: RecoveredService): int
    return rs.contract_id
end svc_contract_id

fn svc_restart_count(rs: RecoveredService): int
    return rs.restart_count
end svc_restart_count

fn svc_last_start_time(rs: RecoveredService): int
    return rs.last_start_time
end svc_last_start_time

fn svc_last_exit_code(rs: RecoveredService): int
    return rs.last_exit_code
end svc_last_exit_code

// ============================================================================
// Outgoing — serialize running service state to state.toml
// ============================================================================

fn serialize_state(table: supervisor.ServiceTable, boot_time: int): bool
    let tmp_path = STATE_TMP_PATH()
    let final_path = STATE_FILE_PATH()
    let dir_path = STATE_DIR()

    // O_WRONLY|O_CREAT|O_TRUNC, mode 0600
    let flags = fd.O_WRONLY() + fd.O_CREAT() + fd.O_TRUNC()
    let out = fd.fd_open(tmp_path, flags, 384)

    if out < 0
        println("replace: serialize: cannot open " + tmp_path)
        return false
    end if

    // Write boot_time header
    let header = str.concat("boot_time = ", int_to_str(boot_time))
    let _ = fd.fd_write(out, str.concat(header, "\n"))

    // Iterate services — only RUNNING ones go in. Skip the rest.
    let count = supervisor.service_count(table)
    mut i = 0
    while i < count
        let rt = supervisor.get_runtime(table, i)
        if supervisor.rt_state(rt) == supervisor.STATE_RUNNING()
            let def = supervisor.rt_def(rt)
            let _ = fd.fd_write(out, "\n[[service]]\n")
            let _ = fd.fd_write(out, str.concat("name = \"", str.concat(config.svc_name(def), "\"\n")))
            let _ = fd.fd_write(out, str.concat("contract_id = ", str.concat(int_to_str(supervisor.rt_contract_id(rt)), "\n")))
            let _ = fd.fd_write(out, str.concat("restart_count = ", str.concat(int_to_str(supervisor.rt_restart_count(rt)), "\n")))
            let _ = fd.fd_write(out, str.concat("last_start_time = ", str.concat(int_to_str(supervisor.rt_last_start_time(rt)), "\n")))
            let _ = fd.fd_write(out, str.concat("last_exit_code = ", str.concat(int_to_str(supervisor.rt_last_exit_code(rt)), "\n")))
        end if
        i = i + 1
    end while

    // fsync + close
    if zyginit_fsync(out) < 0
        println("replace: serialize: fsync failed")
        let _ = fd.fd_close(out)
        let _ = zyginit_unlink(tmp_path)
        return false
    end if
    let _ = fd.fd_close(out)

    // Atomic rename
    if zyginit_rename(tmp_path, final_path) != 0
        println("replace: serialize: rename to " + final_path + " failed")
        let _ = zyginit_unlink(tmp_path)
        return false
    end if

    // fsync the parent dir so the rename is durable
    let _ = zyginit_fsync_path(dir_path)

    return true
end serialize_state

// Local int_to_str — replicate the supervisor.reef pattern. Keeps the
// module standalone (no cross-module helper exposure).
fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if
    mut value = n
    mut neg = false
    if n < 0
        value = 0 - n
        neg = true
    end if
    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while
    if neg
        result = str.concat("-", result)
    end if
    return result
end int_to_str

// ============================================================================
// Incoming — recover serialized state on restart
// ============================================================================

// Local int parser with default. Handles negative numbers.
// Empty string or non-numeric input yields default_val.
fn str_to_int_or(s: string, default_val: int): int
    let n = str.length(s)
    if n == 0
        return default_val
    end if
    mut start = 0
    mut neg = false
    if str.char_at(s, 0) == '-'
        neg = true
        start = 1
    end if
    if start >= n
        return default_val
    end if
    mut result = 0
    mut i = start
    while i < n
        let c = str.char_at(s, i)
        if c < '0' or c > '9'
            return default_val
        end if
        result = result * 10 + (c - '0')
        i = i + 1
    end while
    if neg
        return 0 - result
    end if
    return result
end str_to_int_or

fn recover_state(current_boot_time: int): RecoveredState
    let path = STATE_FILE_PATH()

    if not file.fileExists(path)
        return new_recovered_state()
    end if

    let content_r = file.readFile(path)
    if res.is_err(content_r)
        let _ = zyginit_unlink(path)
        return new_recovered_state()
    end if
    let content = res.unwrap_ok(content_r)
    if str.length(content) == 0
        let _ = zyginit_unlink(path)
        return new_recovered_state()
    end if

    let keys = toml.toml_alloc_keys()
    let vals = toml.toml_alloc_values()
    let count_r = toml.toml_parse(content, keys, vals)
    if res.is_err(count_r)
        println("replace: recover: parse error in " + path + " — ignoring")
        let _ = zyginit_unlink(path)
        return new_recovered_state()
    end if
    let count = res.unwrap_ok(count_r)

    if count == 0
        println("replace: recover: parse error or empty in " + path + " — ignoring")
        let _ = zyginit_unlink(path)
        return new_recovered_state()
    end if

    if not toml.toml_has_key(keys, vals, count, "boot_time")
        println("replace: recover: missing boot_time in " + path + " — ignoring")
        let _ = zyginit_unlink(path)
        return new_recovered_state()
    end if

    let saved_boot = toml.toml_get_int(keys, vals, count, "boot_time")
    if saved_boot != current_boot_time or current_boot_time < 0
        println("replace: recover: stale state file (boot_time " + int_to_str(saved_boot) +
                " != current " + int_to_str(current_boot_time) + "); ignoring")
        let _ = zyginit_unlink(path)
        return new_recovered_state()
    end if

    let n = toml.toml_array_count(keys, count, "service")
    let arr = new [RecoveredService](n)
    mut i = 0
    while i < n
        let name     = toml.toml_array_get(keys, vals, count, "service", i, "name")
        let ctid_str = toml.toml_array_get(keys, vals, count, "service", i, "contract_id")
        let rc_str   = toml.toml_array_get(keys, vals, count, "service", i, "restart_count")
        let lst_str  = toml.toml_array_get(keys, vals, count, "service", i, "last_start_time")
        let lec_str  = toml.toml_array_get(keys, vals, count, "service", i, "last_exit_code")

        arr[i] = RecoveredService{
            name: name,
            contract_id: str_to_int_or(ctid_str, 0 - 1),
            restart_count: str_to_int_or(rc_str, 0),
            last_start_time: str_to_int_or(lst_str, 0),
            last_exit_code: str_to_int_or(lec_str, 0 - 1)
        }
        i = i + 1
    end while

    // State file consumed — delete to avoid panic-restart loops.
    let _ = zyginit_unlink(path)

    return RecoveredState{
        boot_time: saved_boot,
        services: arr,
        count: n
    }
end recover_state

// ============================================================================
// Pre-condition check — transient state detection
// ============================================================================

fn check_preconditions(table: supervisor.ServiceTable): string
    let count = supervisor.service_count(table)
    mut report = ""
    mut found = 0
    mut i = 0
    while i < count
        let rt = supervisor.get_runtime(table, i)
        let st = supervisor.rt_state(rt)
        // STATE_WAITING here means "restart delay pending" — services
        // filtered by runlevel are transitioned to STATE_STOPPED at
        // boot time (see supervisor.mark_runlevel_filtered), and the
        // table is fully started before the event loop entry that
        // processes the replace flag, so "not-yet-started" doesn't
        // occur here either.
        if st == supervisor.STATE_STARTING() or st == supervisor.STATE_STOPPING() or st == supervisor.STATE_WAITING()
            let entry = str.concat(config.svc_name(supervisor.rt_def(rt)),
                str.concat(":", supervisor.state_name(st)))
            if found > 0
                report = str.concat(report, ", ")
            end if
            report = str.concat(report, entry)
            found = found + 1
        end if
        i = i + 1
    end while
    return report
end check_preconditions

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: shutdown.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: PID-1 shutdown primitives — uadmin(2) FFI and shutdown-type
             constants.

******************************************************************************/

module shutdown

export
    // Shutdown function codes (sys/uadmin.h A_SHUTDOWN fcn values)
    fn AD_HALT(): int
    fn AD_BOOT(): int
    fn AD_POWEROFF(): int

    // Symbolic shutdown-type codes used internally by zyginit.
    // These are NOT the uadmin AD_* codes — they're zyginit's own
    // enum for distinguishing what a shutdown was triggered as,
    // before it's mapped to AD_* at the actual uadmin call site.
    fn SHUT_NONE(): int
    fn SHUT_HALT(): int
    fn SHUT_REBOOT(): int
    fn SHUT_POWEROFF(): int

    // Map our internal type to the uadmin fcn code.
    fn to_ad_code(shut_type: int): int

    // Call uadmin(A_SHUTDOWN, fcn, 0). Returns 0 on success, -1 on error.
    // Only succeeds when running as PID 1.
    fn do_shutdown(fcn: int): int

    // Flush dirty page-cache buffers to disk (POSIX sync(2)).
    proc do_sync()
end export

extern "C" fn zyginit_shutdown(fcn: int): int
extern "C" proc zyginit_sync()

fn AD_HALT(): int     return 0 end AD_HALT
fn AD_BOOT(): int     return 1 end AD_BOOT
fn AD_POWEROFF(): int return 6 end AD_POWEROFF

fn SHUT_NONE(): int     return 0 end SHUT_NONE
fn SHUT_HALT(): int     return 1 end SHUT_HALT
fn SHUT_REBOOT(): int   return 2 end SHUT_REBOOT
fn SHUT_POWEROFF(): int return 3 end SHUT_POWEROFF

fn to_ad_code(shut_type: int): int
    if shut_type == SHUT_HALT()
        return AD_HALT()
    elif shut_type == SHUT_REBOOT()
        return AD_BOOT()
    elif shut_type == SHUT_POWEROFF()
        return AD_POWEROFF()
    end if
    // Default to halt for unknown / NONE
    return AD_HALT()
end to_ad_code

fn do_shutdown(fcn: int): int
    return zyginit_shutdown(fcn)
end do_shutdown

proc do_sync()
    zyginit_sync()
end do_sync

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: supervisor.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Service lifecycle management — fork/exec, state, restart

******************************************************************************/

module supervisor

import condition
import config
import contract
import ui
import io.dir
import io.file
import sys.env as sysenv
import sys.fd as fd
import sys.process as process
import sys.signal as signal
import time.time as time
import time.clock as clock
import collections.hashmap as hashmap
import core.str
import core.result as res
import core.option as opt

export
    type ServiceRuntime
    type ServiceTable

    // State constants
    fn STATE_DISABLED(): int
    fn STATE_WAITING(): int
    fn STATE_STARTING(): int
    fn STATE_RUNNING(): int
    fn STATE_STOPPING(): int
    fn STATE_STOPPED(): int
    fn STATE_FAILED(): int
    fn STATE_MAINTENANCE(): int
    fn STATE_SKIPPED(): int
    fn state_name(state: int): string

    // ServiceRuntime accessors
    fn rt_state(rt: ServiceRuntime): int
    fn rt_pid(rt: ServiceRuntime): int
    fn rt_contract_id(rt: ServiceRuntime): int
    fn rt_restart_count(rt: ServiceRuntime): int
    fn rt_last_exit_code(rt: ServiceRuntime): int
    fn rt_last_start_time(rt: ServiceRuntime): int
    fn rt_def(rt: ServiceRuntime): config.ServiceDef
    fn rt_skip_reason(rt: ServiceRuntime): string

    // ServiceTable operations
    fn new_service_table(max_services: int): ServiceTable
    fn add_service(table: ServiceTable, def: config.ServiceDef): int
    fn find_service(table: ServiceTable, name: string): int
    fn find_by_contract(table: ServiceTable, contract_id: int): int
    fn service_count(table: ServiceTable): int
    fn get_runtime(table: ServiceTable, idx: int): ServiceRuntime
    fn conflicts_with(table: ServiceTable, a_idx: int, b_idx: int): bool
    fn conflicting_running_peer(table: ServiceTable, idx: int): int
    fn service_name_at(table: ServiceTable, idx: int): string
    proc mark_conflict_failed(table: ServiceTable, idx: int, other_name: string)

    // Lifecycle
    fn start_service(table: ServiceTable, idx: int): bool
    fn stop_service(table: ServiceTable, idx: int): bool
    proc handle_contract_event(table: ServiceTable, contract_id: int, hint_exit_code: int)
    proc handle_child_exit(table: ServiceTable, pid: int, exit_code: int)
    proc check_stop_timeouts(table: ServiceTable)
    proc check_restart_delays(table: ServiceTable)

    // Oneshot teardown
    fn stop_oneshot(table: ServiceTable, idx: int): bool

    // Reload support
    proc mark_runlevel_filtered(table: ServiceTable, idx: int)
    proc disable_service(table: ServiceTable, idx: int)

    // Adopt runtime fields directly — used by the live-replace recovery path
    // (main.apply_recovered_state) and by utils/replace_probe. Production
    // startup and supervision go through start_service / handle_contract_event.
    proc adopt_runtime(table: ServiceTable, idx: int, state: int, pid: int,
                       contract_id: int, restart_count: int,
                       last_exit_code: int, last_start_time: int)
    fn make_def_with_name(name: string): config.ServiceDef

    // Status
    fn get_status_line(table: ServiceTable, idx: int): string
    fn format_duration(seconds: int): string

    // Log directory
    fn log_dir(): string
    fn get_service_log(name: string): string
end export

fn LOG_DIR(): string
    // Persistent on-disk default. /var/run is tmpfs and gets wiped on every
    // reboot, which makes diagnosing PID-1 boot failures nearly impossible —
    // the log of what zyginit did is gone before the next boot can read it.
    // /var/log lives on the BE's ZFS dataset so it survives across reboots
    // and is readable by mounting the BE from another BE if boot fails.
    return sysenv.get_env_or("ZYGINIT_LOG_DIR", "/var/log/zyginit")
end LOG_DIR

// Central operational log for the supervisor itself (as opposed to the
// per-service <name>.log files). Records events that would otherwise vanish
// — most importantly spawn failures, where the service child never runs and
// so writes nothing to its own log. See bug 003.
fn ZYGINIT_LOG_PATH(): string
    return str.concat(LOG_DIR(), "/zyginit.log")
end ZYGINIT_LOG_PATH

// Append a single timestamped line to the central zyginit log. Best-effort:
// any failure (dir missing, no space, priv-dropped child) is swallowed so
// logging never blocks or aborts the supervisor. Uses only fd syscalls, so
// it is safe to call from a forked child before exec.
proc sup_log(msg: string)
    let flags = fd.O_WRONLY() + fd.O_CREAT() + fd.O_APPEND()
    let f = fd.fd_open(ZYGINIT_LOG_PATH(), flags, 420)
    if f >= 0
        let line = str.concat(str.concat("[", int_to_str(time.time_now())),
                              str.concat("] ", str.concat(msg, "\n")))
        let _ = fd.fd_write(f, line)
        let _2 = fd.fd_close(f)
    end if
end sup_log

// Exec retry policy for service start commands. On a fresh first boot,
// devfsadm + ZFS-pool-finalize I/O contention can make a stat()/exec of the
// start command (or its #! interpreter) transiently fail even for a valid,
// executable, absolute path. A bounded retry rides out the transient miss; a
// genuinely-missing command still fails every attempt. See bug 003.
fn EXEC_MAX_ATTEMPTS(): int
    return 5
end EXEC_MAX_ATTEMPTS

fn EXEC_RETRY_DELAY_MS(): int
    return 100
end EXEC_RETRY_DELAY_MS

// Privilege separation FFI wrappers
extern "C" fn zyginit_getuid_by_name(name: string): int
extern "C" fn zyginit_getgid_by_username(name: string): int
extern "C" fn zyginit_getgid_by_name(name: string): int
extern "C" fn zyginit_drop_privileges(username: string, uid: int, gid: int): int

// ============================================================================
// State constants
// ============================================================================

fn STATE_DISABLED(): int
    return 0
end STATE_DISABLED

fn STATE_WAITING(): int
    return 1
end STATE_WAITING

fn STATE_STARTING(): int
    return 2
end STATE_STARTING

fn STATE_RUNNING(): int
    return 3
end STATE_RUNNING

fn STATE_STOPPING(): int
    return 4
end STATE_STOPPING

fn STATE_STOPPED(): int
    return 5
end STATE_STOPPED

fn STATE_FAILED(): int
    return 6
end STATE_FAILED

fn STATE_MAINTENANCE(): int
    return 7
end STATE_MAINTENANCE

fn STATE_SKIPPED(): int
    return 8
end STATE_SKIPPED

fn state_name(state: int): string
    if state == 0
        return "disabled"
    elif state == 1
        return "waiting"
    elif state == 2
        return "starting"
    elif state == 3
        return "running"
    elif state == 4
        return "stopping"
    elif state == 5
        return "stopped"
    elif state == 6
        return "failed"
    elif state == 7
        return "maintenance"
    elif state == 8
        return "skipped"
    end if
    return "unknown"
end state_name

// ============================================================================
// ServiceRuntime type
// ============================================================================

type ServiceRuntime = struct
    def: config.ServiceDef
    state: int
    contract_id: int
    pid: int
    restart_count: int
    last_exit_code: int
    last_start_time: int
    stop_requested_time: int
    restart_scheduled_time: int
    skip_reason: string
end ServiceRuntime

fn new_runtime(def: config.ServiceDef): ServiceRuntime
    return ServiceRuntime{
        def: def,
        state: STATE_WAITING(),
        contract_id: 0 - 1,
        pid: 0 - 1,
        restart_count: 0,
        last_exit_code: 0 - 1,
        last_start_time: 0,
        stop_requested_time: 0,
        restart_scheduled_time: 0,
        skip_reason: ""
    }
end new_runtime

fn rt_state(rt: ServiceRuntime): int
    return rt.state
end rt_state

fn rt_pid(rt: ServiceRuntime): int
    return rt.pid
end rt_pid

fn rt_contract_id(rt: ServiceRuntime): int
    return rt.contract_id
end rt_contract_id

fn rt_restart_count(rt: ServiceRuntime): int
    return rt.restart_count
end rt_restart_count

fn rt_last_exit_code(rt: ServiceRuntime): int
    return rt.last_exit_code
end rt_last_exit_code

fn rt_last_start_time(rt: ServiceRuntime): int
    return rt.last_start_time
end rt_last_start_time

fn rt_def(rt: ServiceRuntime): config.ServiceDef
    return rt.def
end rt_def

fn rt_skip_reason(rt: ServiceRuntime): string
    return rt.skip_reason
end rt_skip_reason

// ============================================================================
// ServiceTable type
// ============================================================================

type ServiceTable = struct
    runtimes: [ServiceRuntime]
    count: int
    max: int
    name_map: hashmap.HashMap[int]
    contract_map: hashmap.HashMap[int]
end ServiceTable

fn new_service_table(max_services: int): ServiceTable
    return ServiceTable{
        runtimes: new [ServiceRuntime](max_services),
        count: 0,
        max: max_services,
        name_map: hashmap.create[:int](0 - 1),
        contract_map: hashmap.create[:int](0 - 1)
    }
end new_service_table

fn add_service(table: ServiceTable, def: config.ServiceDef): int
    if table.count >= table.max
        return 0 - 1
    end if

    let idx = table.count
    table.runtimes[idx] = new_runtime(def)
    table.name_map.set(config.svc_name(def), idx)
    table.count = table.count + 1
    return idx
end add_service

fn find_service(table: ServiceTable, name: string): int
    let idx: opt.Option[int] = table.name_map.get(name)
    if opt.is_some(idx)
        return opt.unwrap(idx)
    end if
    return 0 - 1
end find_service

fn find_by_contract(table: ServiceTable, contract_id: int): int
    let key = int_to_str(contract_id)
    let idx: opt.Option[int] = table.contract_map.get(key)
    if opt.is_some(idx)
        return opt.unwrap(idx)
    end if
    return 0 - 1
end find_by_contract

fn service_count(table: ServiceTable): int
    return table.count
end service_count

fn get_runtime(table: ServiceTable, idx: int): ServiceRuntime
    return table.runtimes[idx]
end get_runtime

// True if services a and b are declared mutually exclusive. Symmetric: a
// conflict declared on either side counts for both. Self-comparison and
// unknown names never match.
fn conflicts_with(table: ServiceTable, a_idx: int, b_idx: int): bool
    if a_idx == b_idx
        return false
    end if
    let a_def = table.runtimes[a_idx].def
    let b_def = table.runtimes[b_idx].def
    let a_name = config.svc_name(a_def)
    let b_name = config.svc_name(b_def)

    let a_conf = config.svc_conflicts(a_def)
    let a_n = config.svc_conflicts_count(a_def)
    mut i = 0
    while i < a_n
        if a_conf[i] == b_name
            return true
        end if
        i = i + 1
    end while

    let b_conf = config.svc_conflicts(b_def)
    let b_n = config.svc_conflicts_count(b_def)
    i = 0
    while i < b_n
        if b_conf[i] == a_name
            return true
        end if
        i = i + 1
    end while

    return false
end conflicts_with

// Index of a RUNNING/STARTING service that conflicts with idx, or -1 if none.
// Shared by the start guard and by zygctl start for messaging.
fn conflicting_running_peer(table: ServiceTable, idx: int): int
    mut i = 0
    while i < table.count
        if i != idx and conflicts_with(table, idx, i)
            let st = table.runtimes[i].state
            if st == STATE_RUNNING() or st == STATE_STARTING()
                return i
            end if
        end if
        i = i + 1
    end while
    return 0 - 1
end conflicting_running_peer

// Name of the service at idx (convenience for callers outside this module).
fn service_name_at(table: ServiceTable, idx: int): string
    return config.svc_name(table.runtimes[idx].def)
end service_name_at

// Mark a service FAILED because of a conflict, recording the reason for
// `zygctl status`. The skip_reason field doubles as a generic status reason.
proc mark_conflict_failed(table: ServiceTable, idx: int, other_name: string)
    let rt = table.runtimes[idx]
    rt.state = STATE_FAILED()
    rt.skip_reason = str.concat("conflicts with ", other_name)
    table.runtimes[idx] = rt
end mark_conflict_failed

// ============================================================================
// Signal name to number mapping
// ============================================================================

fn signal_from_name(name: string): int
    if name == "TERM" or name == "SIGTERM"
        return signal.SIGTERM()
    elif name == "HUP" or name == "SIGHUP"
        return signal.SIGHUP()
    elif name == "INT" or name == "SIGINT"
        return signal.SIGINT()
    elif name == "KILL" or name == "SIGKILL"
        return signal.SIGKILL()
    elif name == "USR1" or name == "SIGUSR1"
        return signal.SIGUSR1()
    elif name == "USR2" or name == "SIGUSR2"
        return signal.SIGUSR2()
    end if
    return signal.SIGTERM()
end signal_from_name

// ============================================================================
// Service lifecycle
// ============================================================================

// Start a service: set up contract template, fork, exec.
// Returns true on success.
fn start_service(table: ServiceTable, idx: int): bool
    let rt = table.runtimes[idx]
    let def = rt.def
    let name = config.svc_name(def)

    // Evaluate [condition] block before forking. If conditions fail, the
    // service is transitioned to STATE_SKIPPED — no process is ever forked.
    let cond_result = condition.evaluate_conditions(def)
    if condition.cond_passed(cond_result) == false
        rt.state = STATE_SKIPPED()
        rt.skip_reason = condition.cond_reason(cond_result)
        table.runtimes[idx] = rt
        ui.ui_event_skipped(name, rt.skip_reason)
        return true
    end if

    // Conflict guard: refuse to start when a mutually-exclusive peer is already
    // running or starting. Leaves this service's state unchanged. Covers
    // zygctl start, runlevel transitions, and restarts (all funnel here).
    let conflict_peer = conflicting_running_peer(table, idx)
    if conflict_peer >= 0
        let other = config.svc_name(table.runtimes[conflict_peer].def)
        if ui.ui_mode() == ui.MODE_PLAIN()
            println(str.concat(str.concat("supervisor: cannot start ", name),
                    str.concat(": conflicts with running service ", other)))
        end if
        return false
    end if

    // Emit "starting" event so the UI spinner activates before the fork.
    ui.ui_event_starting(name)

    // Set up contract template (will fail on Linux — that's expected)
    let tmpl_fd = contract.setup_template()

    // Fork
    let pid = process.process_fork()

    if pid < 0
        rt.state = STATE_FAILED()
        table.runtimes[idx] = rt
        ui.ui_event_failed(name, 0 - 1, 0)
        sup_log(str.concat(name, ": fork failed"))
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("supervisor: fork failed for " + name)
        end if
        if tmpl_fd >= 0
            contract.clear_template(tmpl_fd)
        end if
        return false
    end if

    if pid == 0
        // CHILD PROCESS

        // Redirect fd 0 to /dev/null BEFORE setsid. PID 1 has /dev/console on
        // fd 0/1/2 (from setup_pid1_console), and if the new session is born
        // holding that inherited tty fd, illumos may auto-claim /dev/console
        // as the session's ctty even without an explicit O_NOCTTY-less open.
        // That blocks ttymon (in console-login) from claiming the console
        // later. See bugs/001-supervisor-leaves-console-as-fd0-in-children.md.
        let null_fd = fd.fd_open("/dev/null", fd.O_RDWR(), 0)
        if null_fd >= 0
            fd.fd_dup2(null_fd, 0)
            fd.fd_close(null_fd)
        end if

        process.process_setsid()

        // Redirect stdout/stderr to per-service log file
        let log_path = str.concat(str.concat(LOG_DIR(), "/"), str.concat(name, ".log"))
        let log_flags = fd.O_WRONLY() + fd.O_CREAT() + fd.O_TRUNC()
        let log_fd = fd.fd_open(log_path, log_flags, 420)
        if log_fd >= 0
            fd.fd_dup2(log_fd, 1)
            fd.fd_dup2(log_fd, 2)
            fd.fd_close(log_fd)
        end if

        // Change working directory if specified
        let wdir = config.svc_working_dir(def)
        if str.length(wdir) > 0
            dir.change_dir(wdir)
        end if

        // Default PATH for service children. zyginit as PID 1 inherits
        // a sparse env from the kernel, so without this, services like
        // shell-script wrappers can't find bare command names. The
        // service's own [exec] environment list (below) can override.
        sysenv.set_env("PATH", "/usr/sbin:/usr/bin:/sbin")

        // Set environment variables
        let env_vars = config.svc_environment(def)
        let env_count = config.svc_environment_count(def)
        mut ei = 0
        while ei < env_count
            let entry = env_vars[ei]
            let eq_pos = str.index_of(entry, "=")
            if eq_pos > 0
                let key = str.substring(entry, 0, eq_pos)
                let val = str.substring(entry, eq_pos + 1, str.length(entry) - eq_pos - 1)
                sysenv.set_env(key, val)
            end if
            ei = ei + 1
        end while

        // Drop privileges if user/group specified
        let svc_user = config.svc_user(def)
        let svc_group = config.svc_group(def)
        if str.length(svc_user) > 0
            let uid = zyginit_getuid_by_name(svc_user)
            mut gid = zyginit_getgid_by_username(svc_user)

            // Override gid if explicit group specified
            if str.length(svc_group) > 0
                gid = zyginit_getgid_by_name(svc_group)
            end if

            if uid < 0 or gid < 0
                // User/group lookup failed — abort child
                process.exit_now(126)
            end if

            if zyginit_drop_privileges(svc_user, uid, gid) < 0
                process.exit_now(126)
            end if
        elif str.length(svc_group) > 0
            // Group only (no user change) — not typical but supported
            let gid = zyginit_getgid_by_name(svc_group)
            if gid < 0
                process.exit_now(126)
            end if
        end if

        // Parse start_cmd into program + args
        let cmd = config.svc_start_cmd(def)
        let parts = new [string](32)
        let argc = str.split(cmd, ' ', parts, 32)

        if argc > 0
            let program = parts[0]
            // argv[0] must be the program name (POSIX convention).
            // argv[1..] are the actual arguments.
            let args = new [string](argc)
            mut a = 0
            while a < argc
                args[a] = parts[a]
                a = a + 1
            end while

            // Retry the exec a bounded number of times. process_exec only
            // returns when the exec itself failed (the process image was
            // never replaced), so each loop iteration is a fresh attempt.
            // This absorbs the transient first-boot stat()/exec miss under
            // I/O pressure without masking a genuinely-missing command,
            // which fails every attempt and falls through to exit 127.
            mut attempt = 0
            while attempt < EXEC_MAX_ATTEMPTS()
                process.process_exec(program, args)
                attempt = attempt + 1
                if attempt < EXEC_MAX_ATTEMPTS()
                    clock.sleep_millis(EXEC_RETRY_DELAY_MS())
                end if
            end while
        end if

        // Every exec attempt failed — the start command never ran. Record it
        // loudly instead of vanishing with an empty log (the bug-003 symptom):
        //   - fd 2 → per-service <name>.log; the fd was opened as root before
        //     any privilege drop, so this write survives a dropped-priv child.
        //   - central zyginit.log via sup_log (best-effort; works while root).
        // Then exit 127 ("command not found" convention) so the parent's
        // exit-code plumbing reports a real code rather than the -1 sentinel.
        let fail_msg = str.concat(str.concat(name, ": exec failed for '"),
                                  str.concat(cmd,
                                  str.concat("' after ",
                                  str.concat(int_to_str(EXEC_MAX_ATTEMPTS()), " attempts"))))
        let _ = fd.fd_write(2, str.concat(fail_msg, "\n"))
        sup_log(fail_msg)
        process.exit_now(127)
    end if

    // PARENT PROCESS

    // Get contract ID (will be -1 on Linux)
    mut ctid = 0 - 1
    if tmpl_fd >= 0
        ctid = contract.get_latest_contract()
        contract.clear_template(tmpl_fd)
    end if

    // Update runtime
    rt.state = STATE_RUNNING()
    rt.pid = pid
    rt.contract_id = ctid
    rt.last_start_time = time.time_now()
    rt.skip_reason = ""    // clear any stale conflict/skip reason from a prior failure
    table.runtimes[idx] = rt

    // Register contract mapping
    if ctid >= 0
        table.contract_map.set(int_to_str(ctid), idx)
    end if

    // Fire ui_event_started only for daemons entering RUNNING state.
    // Oneshots must NOT fire here — they only call ui_event_started when
    // the contract-exit event confirms successful completion (in
    // handle_contract_event). Firing here AND on exit causes g_done to
    // double-increment, producing a count like "32/23 done".
    if config.svc_type(def) != config.SERVICE_TYPE_ONESHOT()
        ui.ui_event_started(name, 0)
    end if
    return true
end start_service

// Stop a service: signal the contract or exec the stop command.
// Returns true if stop was initiated.
fn stop_service(table: ServiceTable, idx: int): bool
    let rt = table.runtimes[idx]
    let def = rt.def
    let name = config.svc_name(def)

    if rt.state != STATE_RUNNING()
        return false
    end if

    rt.state = STATE_STOPPING()
    rt.stop_requested_time = time.time_now()
    table.runtimes[idx] = rt

    let stop_method = config.svc_stop_method(def)

    if stop_method == config.STOP_METHOD_EXEC() and str.length(config.svc_stop_cmd(def)) > 0
        // Exec the stop command
        process.process_spawn_shell(config.svc_stop_cmd(def))
        ui.ui_event_stopping(name)
    else
        // Signal the contract (default)
        let sig = signal_from_name(config.svc_stop_signal(def))
        if rt.contract_id >= 0
            contract.kill_contract(rt.contract_id, sig)
        elif rt.pid > 0
            // Fallback: signal the process directly (Linux or no contract)
            process.process_kill(rt.pid, sig)
        end if
        ui.ui_event_stopping(name)
    end if

    return true
end stop_service

// Run a oneshot's declared exec.stop command synchronously.
// Used during shutdown to reverse setup that the matching exec.start did.
// Does nothing if no stop command is declared.
// Returns true if stop was attempted (whether or not it succeeded).
fn stop_oneshot(table: ServiceTable, idx: int): bool
    let rt = table.runtimes[idx]
    let def = rt.def
    let name = config.svc_name(def)

    // Guard (C-1): only oneshots get exec.stop dispatched at shutdown.
    // Daemons that land in STATE_STOPPED already had their stop_method run
    // (via stop_service). Re-running it would be incorrect.
    if config.svc_type(def) != config.SERVICE_TYPE_ONESHOT()
        return false
    end if

    let stop_cmd = config.svc_stop_cmd(def)

    if str.length(stop_cmd) == 0
        // Nothing to reverse — normal for oneshots with no teardown.
        return false
    end if

    if ui.ui_mode() == ui.MODE_PLAIN()
        println("supervisor: running stop for " + name + " (" + stop_cmd + ")")
    end if

    let pid = process.process_spawn_shell(stop_cmd)
    if pid < 0
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("supervisor: " + name + ": stop spawn failed")
        end if
        return true
    end if

    // Bounded wait (C-2): stop scripts that hang shouldn't lock up shutdown.
    // Try-wait loop with a 10s deadline (20 x 500ms).
    mut waits = 0
    mut exited = false
    while not exited and waits < 20
        if process.process_try_wait(pid)
            exited = true
        else
            clock.sleep_millis(500)
            waits = waits + 1
        end if
    end while

    if not exited
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("supervisor: " + name + ": stop timed out, killing")
        end if
        let _ = process.process_kill(pid, signal.SIGKILL())
        // Reap the now-dead child
        let _ = process.process_wait(pid)
    elif process.process_exit_code() != 0
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("supervisor: " + name + ": stop exited non-zero (" +
                    int_to_str(process.process_exit_code()) + ")")
        end if
    end if
    return true
end stop_oneshot

// Handle a contract event (typically "empty" — all processes exited).
// Looks up the service by contract ID and applies restart policy.
proc handle_contract_event(table: ServiceTable, contract_id: int, hint_exit_code: int)
    let idx = find_by_contract(table, contract_id)
    if idx < 0
        return
    end if

    let rt = table.runtimes[idx]
    let def = rt.def
    let name = config.svc_name(def)

    // Resolve exit code: prefer the hint (caller already reaped via SIGCHLD
    // path); else attempt to reap ourselves (contract-fd path arrived first).
    // hint_exit_code is non-negative when the caller has a real exit code;
    // -1 is the "no hint" sentinel matching the post-reap default below.
    mut exit_code = 0 - 1
    if hint_exit_code >= 0
        exit_code = hint_exit_code
    elif rt.pid > 0
        if process.process_try_wait(rt.pid)
            exit_code = process.process_exit_code()
        end if
    end if

    // Reap-race reconciliation (Hammerhead contract path, bug 003).
    // The contract-empty event on the bundle fd can arrive before the
    // child's exit status has been posted for reaping. When that happens
    // we have no hint AND try_wait above could not resolve a code, yet a
    // child is still tracked (rt.pid > 0). Committing the -1 sentinel here
    // would (a) misreport a real exit code — a 127 spawn failure surfaces
    // as -1 — and (b) flip an exit-0 oneshot into a spurious FAILED. Worse,
    // this handler would then clear rt.pid and the contract map, so the
    // catch-all reaper later swallows the true code with nowhere to route
    // it. Defer instead: leave rt.pid and the contract mapping intact and
    // return. reap_children runs unconditionally every poll iteration and
    // re-dispatches this contract with the real exit code (hint >= 0)
    // within ~1s. A daemon that already completed its daemonize handshake
    // has rt.pid == -1 here, so its genuine crash (code truly unknown) is
    // NOT deferred and flows through the logic below as before.
    if hint_exit_code < 0 and exit_code < 0 and rt.pid > 0
        return
    end if

    let svc_type = config.svc_type(def)

    // Task: may run for any duration. Exit 0 = STOPPED (counts as online).
    // Exit != 0 = FAILED. Never restarts. Skips the daemonize handshake.
    if svc_type == config.SERVICE_TYPE_TASK()
        let dur_ms = (time.time_now() - rt.last_start_time) * 1000
        let ec: int = if exit_code >= 0 then exit_code else 0 end if
        rt.pid = 0 - 1
        rt.contract_id = 0 - 1
        rt.last_exit_code = ec
        table.contract_map.remove(int_to_str(contract_id))
        if ec == 0
            rt.state = STATE_STOPPED()
            table.runtimes[idx] = rt
            ui.ui_event_stopped(name, dur_ms)
        else
            rt.state = STATE_FAILED()
            table.runtimes[idx] = rt
            ui.ui_event_failed(name, ec, dur_ms)
        end if
        return
    end if

    // Daemonize handshake: a double-forking daemon (dlmgmtd, syslogd,
    // utmpd, etc.) signals readiness by having its parent exit 0 once
    // the daemonized child is set up. The child stays alive in the same
    // contract (CT_PR_INHERIT). If this call came from the PID-reap
    // path (hint_exit_code >= 0) and the parent exited cleanly while
    // we're still RUNNING, this is the daemonize handshake — NOT a
    // service stop. Clear the original PID so reap_children stops
    // chasing it, but keep contract_id and contract_map intact: the
    // eventual contract-empty event from the bundle fd will route back
    // here with hint_exit_code = -1 and we'll process the real stop
    // through the normal logic below.
    if svc_type == config.SERVICE_TYPE_DAEMON() and hint_exit_code >= 0 and exit_code == 0 and rt.state == STATE_RUNNING()
        rt.pid = 0 - 1
        rt.last_exit_code = exit_code
        table.runtimes[idx] = rt
        return
    end if

    rt.last_exit_code = exit_code
    rt.pid = 0 - 1
    rt.contract_id = 0 - 1

    // Remove contract mapping
    table.contract_map.remove(int_to_str(contract_id))

    // Apply restart policy
    let policy = config.svc_restart_policy(def)

    // Oneshot services are "done" after running — don't restart
    if svc_type == config.SERVICE_TYPE_ONESHOT()
        let dur_ms = (time.time_now() - rt.last_start_time) * 1000
        if exit_code == 0
            rt.state = STATE_STOPPED()
            table.runtimes[idx] = rt
            ui.ui_event_started(name, dur_ms)
        else
            rt.state = STATE_FAILED()
            table.runtimes[idx] = rt
            ui.ui_event_failed(name, exit_code, dur_ms)
        end if
        return
    end if

    // Check if we were in the process of stopping
    if rt.state == STATE_STOPPING()
        let dur_ms = (time.time_now() - rt.last_start_time) * 1000
        rt.state = STATE_STOPPED()
        table.runtimes[idx] = rt
        ui.ui_event_stopped(name, dur_ms)
        return
    end if

    // Daemon restart logic
    mut should_restart = false

    if policy == config.RESTART_ALWAYS()
        should_restart = true
    elif policy == config.RESTART_FAILURE() and exit_code != 0
        should_restart = true
    end if

    if should_restart
        // Check max_retries
        let max = config.svc_max_retries(def)
        if max >= 0 and rt.restart_count >= max
            rt.state = STATE_MAINTENANCE()
            table.runtimes[idx] = rt
            if ui.ui_mode() == ui.MODE_PLAIN()
                println("supervisor: " + name + " entered maintenance (max retries)")
            end if
            return
        end if

        // Schedule restart after delay
        rt.state = STATE_WAITING()
        rt.restart_count = rt.restart_count + 1
        rt.restart_scheduled_time = time.time_now() + config.svc_restart_delay(def)
        if ui.ui_mode() == ui.MODE_PLAIN()
            println("supervisor: " + name + " scheduled for restart")
        end if
    else
        let dur_ms = (time.time_now() - rt.last_start_time) * 1000
        rt.state = STATE_STOPPED()
        table.runtimes[idx] = rt
        if exit_code == 0
            ui.ui_event_stopped(name, dur_ms)
        else
            ui.ui_event_failed(name, exit_code, dur_ms)
        end if
    end if

    table.runtimes[idx] = rt
end handle_contract_event

// Handle a child exit by PID (for Linux/non-contract mode).
// Scans the table for a matching PID.
proc handle_child_exit(table: ServiceTable, pid: int, exit_code: int)
    mut i = 0
    while i < table.count
        let rt = table.runtimes[i]
        if rt.pid == pid
            // Simulate a contract event with a fake contract id
            // Reuse handle_contract_event logic by temporarily setting fields
            rt.last_exit_code = exit_code
            rt.pid = 0 - 1
            table.runtimes[i] = rt

            // Use contract_id if available, otherwise handle directly
            if rt.contract_id >= 0
                handle_contract_event(table, rt.contract_id, exit_code)
            else
                // Inline the restart logic for non-contract mode
                let def = rt.def
                let name = config.svc_name(def)
                let policy = config.svc_restart_policy(def)
                let svc_type = config.svc_type(def)

                if svc_type == config.SERVICE_TYPE_TASK()
                    let dur_ms = (time.time_now() - rt.last_start_time) * 1000
                    if exit_code == 0
                        rt.state = STATE_STOPPED()
                        table.runtimes[i] = rt
                        ui.ui_event_stopped(name, dur_ms)
                    else
                        rt.state = STATE_FAILED()
                        rt.last_exit_code = exit_code
                        table.runtimes[i] = rt
                        ui.ui_event_failed(name, exit_code, dur_ms)
                    end if
                elif svc_type == config.SERVICE_TYPE_ONESHOT()
                    if exit_code == 0
                        rt.state = STATE_STOPPED()
                    else
                        rt.state = STATE_FAILED()
                    end if
                elif rt.state == STATE_STOPPING()
                    rt.state = STATE_STOPPED()
                else
                    mut should_restart = false
                    if policy == config.RESTART_ALWAYS()
                        should_restart = true
                    elif policy == config.RESTART_FAILURE() and exit_code != 0
                        should_restart = true
                    end if

                    if should_restart
                        let max = config.svc_max_retries(def)
                        if max >= 0 and rt.restart_count >= max
                            rt.state = STATE_MAINTENANCE()
                        else
                            rt.state = STATE_WAITING()
                            rt.restart_count = rt.restart_count + 1
                            rt.restart_scheduled_time = time.time_now() + config.svc_restart_delay(def)
                        end if
                    else
                        rt.state = STATE_STOPPED()
                    end if
                end if

                table.runtimes[i] = rt
            end if

            return
        end if
        i = i + 1
    end while
end handle_child_exit

// Check for services whose stop timeout has expired and escalate to SIGKILL.
proc check_stop_timeouts(table: ServiceTable)
    let now = time.time_now()
    mut i = 0
    while i < table.count
        let rt = table.runtimes[i]
        if rt.state == STATE_STOPPING() and rt.stop_requested_time > 0
            let timeout = config.svc_stop_timeout(rt.def)
            if now - rt.stop_requested_time >= timeout
                let name = config.svc_name(rt.def)
                if ui.ui_mode() == ui.MODE_PLAIN()
                    println("supervisor: " + name + " stop timeout, sending SIGKILL")
                end if
                if rt.contract_id >= 0
                    contract.kill_contract(rt.contract_id, signal.SIGKILL())
                elif rt.pid > 0
                    process.process_kill(rt.pid, signal.SIGKILL())
                end if
            end if
        end if
        i = i + 1
    end while
end check_stop_timeouts

// Check for services whose restart delay has elapsed and start them.
proc check_restart_delays(table: ServiceTable)
    let now = time.time_now()
    mut i = 0
    while i < table.count
        let rt = table.runtimes[i]
        if rt.state == STATE_WAITING() and rt.restart_scheduled_time > 0
            if now >= rt.restart_scheduled_time
                rt.restart_scheduled_time = 0
                table.runtimes[i] = rt
                let name = config.svc_name(rt.def)
                if ui.ui_mode() == ui.MODE_PLAIN()
                    println("supervisor: restarting " + name)
                end if
                start_service(table, i)
            end if
        end if
        i = i + 1
    end while
end check_restart_delays

// ============================================================================
// Reload support
// ============================================================================

// Mark a service as disabled and stop it if running.
// Does not remove from the table (to avoid index invalidation).
proc disable_service(table: ServiceTable, idx: int)
    let rt = table.runtimes[idx]

    if rt.state == STATE_RUNNING()
        stop_service(table, idx)
    end if

    rt.state = STATE_DISABLED()
    rt.restart_scheduled_time = 0
    table.runtimes[idx] = rt
end disable_service

// Mark a service as filtered-out-by-runlevel at boot time. Sets state
// to STOPPED, the same terminal state that runtime runlevel transitions
// produce for services that exit because they're no longer in the
// active set. Without this, runlevel-filtered services sit in
// STATE_WAITING forever — misleading in status output and tripping
// pre-condition checks (e.g., replace's check_preconditions). The
// state machine is more consistent if all "service didn't run / no
// longer running" cases collapse to STOPPED regardless of how they
// got there.
proc mark_runlevel_filtered(table: ServiceTable, idx: int)
    let rt = table.runtimes[idx]
    rt.state = STATE_STOPPED()
    table.runtimes[idx] = rt
end mark_runlevel_filtered

// Adopt runtime fields directly on a ServiceRuntime, bypassing the
// normal start/stop lifecycle. Used by main.apply_recovered_state for
// live-replace recovery (the new zyginit doesn't fork the service —
// it inherits a contract held by the same PID-1 proc_t and rebuilds
// in-memory bookkeeping) and by utils/replace_probe for state-file
// round-trip tests. Production startup and supervision still go
// through start_service / handle_contract_event.
proc adopt_runtime(table: ServiceTable, idx: int, state: int, pid: int,
                   contract_id: int, restart_count: int,
                   last_exit_code: int, last_start_time: int)
    let rt = table.runtimes[idx]
    rt.state = state
    rt.pid = pid
    rt.contract_id = contract_id
    rt.restart_count = restart_count
    rt.last_exit_code = last_exit_code
    rt.last_start_time = last_start_time
    table.runtimes[idx] = rt

    // Register contract mapping so handle_contract_event can route
    // events for this contract back to the right service.
    if contract_id >= 0
        table.contract_map.set(int_to_str(contract_id), idx)
    end if
end adopt_runtime

// Test/probe helper — build a ServiceDef with a given name and all other
// fields set to defaults. Wraps config.new_service_def() so external
// callers (utils/replace_probe) don't need to reconstruct the struct
// literal (cross-module struct literal syntax is not supported in Reef).
fn make_def_with_name(name: string): config.ServiceDef
    mut def = config.new_service_def()
    def.name = name
    return def
end make_def_with_name

// ============================================================================
// Status
// ============================================================================

fn get_status_line(table: ServiceTable, idx: int): string
    let rt = table.runtimes[idx]
    let name = config.svc_name(rt.def)
    let st = state_name(rt.state)
    mut line = name + " " + st

    if rt.pid > 0
        line = str.concat(line, " pid=")
        line = str.concat(line, int_to_str(rt.pid))
    end if

    if rt.contract_id >= 0
        line = str.concat(line, " ctid=")
        line = str.concat(line, int_to_str(rt.contract_id))
    end if

    // Uptime (only for running services with a valid start time)
    if rt.state == STATE_RUNNING() and rt.last_start_time > 0
        let uptime = time.time_now() - rt.last_start_time
        line = str.concat(line, " uptime=")
        line = str.concat(line, format_duration(uptime))
    end if

    // Exit code (show for stopped/failed/maintenance states)
    if rt.last_exit_code >= 0 and rt.state != STATE_RUNNING() and rt.state != STATE_WAITING()
        line = str.concat(line, " exit=")
        line = str.concat(line, int_to_str(rt.last_exit_code))
    end if

    // Restart count (show if non-zero)
    if rt.restart_count > 0
        line = str.concat(line, " restarts=")
        line = str.concat(line, int_to_str(rt.restart_count))
    end if

    return line
end get_status_line

// Format a duration in seconds to a human-readable string.
// Examples: "45s", "5m30s", "2h15m", "1d3h"
fn format_duration(seconds: int): string
    if seconds < 0
        return "0s"
    end if

    let days = seconds / 86400
    let remaining_after_days = seconds % 86400
    let hours = remaining_after_days / 3600
    let remaining_after_hours = remaining_after_days % 3600
    let minutes = remaining_after_hours / 60
    let secs = remaining_after_hours % 60

    if days > 0
        mut result = int_to_str(days) + "d"
        if hours > 0
            result = str.concat(result, int_to_str(hours))
            result = str.concat(result, "h")
        end if
        return result
    end if

    if hours > 0
        mut result = int_to_str(hours) + "h"
        if minutes > 0
            result = str.concat(result, int_to_str(minutes))
            result = str.concat(result, "m")
        end if
        return result
    end if

    if minutes > 0
        mut result = int_to_str(minutes) + "m"
        if secs > 0
            result = str.concat(result, int_to_str(secs))
            result = str.concat(result, "s")
        end if
        return result
    end if

    return int_to_str(secs) + "s"
end format_duration

// ============================================================================
// Log access
// ============================================================================

fn log_dir(): string
    return LOG_DIR()
end log_dir

fn get_service_log(name: string): string
    let log_path = str.concat(str.concat(LOG_DIR(), "/"), str.concat(name, ".log"))
    if not file.fileExists(log_path)
        return "no log available for " + name + "\n"
    end if
    let content_r = file.readFile(log_path)
    if res.is_err(content_r)
        return "no log available for " + name + "\n"
    end if
    let content = res.unwrap_ok(content_r)
    if str.length(content) == 0
        return "(empty log)\n"
    end if
    return content
end get_service_log

// ============================================================================
// Helpers
// ============================================================================

fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: ui.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Unified visual rendering: palette, glyphs, sigil, rolling tape, divider gauge, spinner, final cards.
     
******************************************************************************/

module ui

import core.str as str
import sys.env as env
import sys.process as process
import time.time as time
import version

export
    fn MODE_PLAIN(): int
    fn MODE_RICH_ASCII(): int
    fn MODE_RICH_16(): int
    fn MODE_RICH_TRUE(): int
    proc ui_init(rich_mode: int)
    proc ui_detect_winsize()
    fn ui_mode(): int
    fn ui_runlevel(): string
    fn ui_demo(scenario: string): int
    fn detect_rich_mode(): int
    fn detect_rich_mode_for_main(): int
    fn paint(token: string, text: string): string
    fn glyph_ok(): string
    fn glyph_fail(): string
    fn glyph_pending(): string
    fn glyph_starting(): string
    fn sigil(): string
    proc ui_boot_start(num_svc: int, num_tiers: int, runlevel: string)
    proc ui_tier_start(tier: int)
    proc ui_tier_done(tier: int)
    proc ui_event_started(name: string, dur_ms: int)
    proc ui_event_failed(name: string, exit_code: int, dur_ms: int)
    proc ui_event_starting(name: string)
    proc ui_event_stopping(name: string)
    proc ui_event_skipped(name: string, reason: string)
    proc ui_tick()
    fn ui_spinner_frame(reverse: bool): string
    fn fmt_divider_gauge(done: int, total: int): string
    type BootStats
    proc ui_boot_complete(stats: BootStats)
    proc ui_shutdown_start(reason: string)
    proc ui_event_stopped(name: string, dur_ms: int)
    proc ui_shutdown_complete(reason: string, elapsed_ms: int)
    fn pad_right(s: string, n: int): string
    fn make_divider(): string
    proc ui_set_mode(m: int)
    fn zyginit_monotonic_ms(): int
end export

type BootStats = struct
    elapsed_ms: int
    online: int
    failed: int
    skipped: int
    slowest: [string]
    slowest_count: int
end BootStats

// Render modes. Decided once at startup by ui_init().
fn MODE_PLAIN(): int        return 0   end MODE_PLAIN
fn MODE_RICH_ASCII(): int   return 1   end MODE_RICH_ASCII
fn MODE_RICH_16(): int      return 2   end MODE_RICH_16
fn MODE_RICH_TRUE(): int    return 3   end MODE_RICH_TRUE

mut g_mode: int = 0
mut g_failed: bool = false   // set if write() to /dev/console errors

// Declared here (before TAPE_HEIGHT) so the C prototype is emitted before
// its first use; also appears grouped with the other tape externs below.
extern "C" fn zyginit_tape_slots(): int

// Dynamic screen size — populated by ui_detect_winsize(), called from
// main.reef after setup_pid1_console() so /dev/console is on fd 1.
// Safe defaults (80x25) used when TIOCGWINSZ fails (Linux dev builds,
// pipes, integration tests with ZYGINIT_FORCE_80x25=1).
mut g_screen_rows: int = 25
mut g_screen_cols: int = 80
mut g_tape_height: int = 12
mut g_line_width: int = 78

fn TAPE_HEIGHT(): int return g_tape_height end TAPE_HEIGHT
fn LINE_WIDTH(): int  return g_line_width  end LINE_WIDTH

mut g_phase: string = ""
mut g_runlevel: string = ""
mut g_num_svc: int = 0
mut g_num_tiers: int = 0
mut g_cur_tier: int = 0
mut g_done: int = 0
mut g_failed_count: int = 0
mut g_skipped: int = 0
mut g_failed_first: string = ""
mut g_failed_first_exit: int = 0
mut g_boot_start_ms: int = 0
mut g_shutdown_reason: string = ""

// Spinner state
mut g_tick: int = 0

// Tape state counters. The backing arrays live in helpers.c (C static buffers)
// to avoid Reef's module-level new[] limitation (Reef emits GCC statement-expr
// initializers which are invalid as C static initializers).
mut g_tape_head: int = 0
mut g_tape_count: int = 0

extern "C" fn zyginit_isatty(fd: int): int
extern "C" fn zyginit_esc_str(): string
extern "C" fn zyginit_monotonic_ms(): int
extern "C" fn zyginit_tape_slots(): int
extern "C" proc zyginit_tape_clear()
extern "C" proc zyginit_tape_set(slot: int, elapsed: int, glyph: string, svc_name: string, note: string, active_flag: int)
extern "C" fn zyginit_tape_get_elapsed(slot: int): int
extern "C" fn zyginit_tape_get_glyph(slot: int): string
extern "C" fn zyginit_tape_get_name(slot: int): string
extern "C" fn zyginit_tape_get_note(slot: int): string
extern "C" fn zyginit_tape_get_active(slot: int): int
extern "C" proc zyginit_tape_set_active(slot: int, active_flag: int)
extern "C" proc zyginit_tape_set_glyph(slot: int, glyph: string)
extern "C" proc zyginit_tape_set_note(slot: int, note: string)
extern "C" fn zyginit_get_winsize(fd: int, out_rows: [int], out_cols: [int]): int

fn N_FRAMES(): int return 4 end N_FRAMES

// Return the current spinner frame character.
// Forward (starting): cycles / - \ |  with increasing g_tick
// Reverse (stopping): cycles | \ - /  with increasing g_tick (unwinds)
fn ui_spinner_frame(reverse: bool): string
    let i = g_tick % N_FRAMES()
    if reverse
        let r = (N_FRAMES() - 1) - i
        if r == 0  return "/"  end if
        if r == 1  return "-"  end if
        if r == 2  return "\\"  end if
        return "|"
    end if
    if i == 0  return "/"  end if
    if i == 1  return "-"  end if
    if i == 2  return "\\"  end if
    return "|"
end ui_spinner_frame

// Pure terminal capability detector (no PID check, no isatty check).
// Inspects only env vars and TERM. Use this from --ui-demo and snapshot tests.
// Production callers (main.reef boot path) should use
// detect_rich_mode_for_main() — it adds the PID-1 and isatty guards.
fn detect_rich_mode(): int
    if env.has_env("ZYGINIT_NO_UI")     return MODE_PLAIN()      end if
    if env.has_env("NO_COLOR")          return MODE_PLAIN()      end if
    let term = env.get_env_or("TERM", "")
    if term == "dumb"                   return MODE_PLAIN()      end if
    if env.has_env("ZYGINIT_ASCII")     return MODE_RICH_ASCII() end if
    if term == "sun"                    return MODE_RICH_16()    end if
    if term == "vt100"                  return MODE_RICH_16()    end if
    if term == "vt220"                  return MODE_RICH_16()    end if
    if term == "sun-color"              return MODE_RICH_TRUE()  end if
    if str.index_of(term, "256color") >= 0
        return MODE_RICH_TRUE()
    end if
    // Hammerhead UEFI framebuffer: kernel doesn't set TERM but tem
    // supports full ANSI/CSI/truecolor. Default to truecolor when
    // we have no TERM hint.
    if str.length(term) == 0            return MODE_RICH_TRUE()  end if
    // Anything else: safe 16-color baseline.
    return MODE_RICH_16()
end detect_rich_mode

// PID-1-aware, tty-aware wrapper around detect_rich_mode.
// Adds: non-PID-1 instances always emit plain; non-tty stdout always emits plain.
// Call this from main.reef boot path; call detect_rich_mode() for tests/demo.
fn detect_rich_mode_for_main(): int
    // Hard overrides
    if env.has_env("ZYGINIT_NO_UI")  return MODE_PLAIN()  end if
    if env.has_env("NO_COLOR")       return MODE_PLAIN()  end if
    // Production gates
    if process.getpid() != 1         return MODE_PLAIN()  end if
    if zyginit_isatty(1) == 0        return MODE_PLAIN()  end if
    // TERM-driven mode
    let term = env.get_env_or("TERM", "")
    if term == "dumb"                return MODE_PLAIN()      end if
    if env.has_env("ZYGINIT_ASCII")  return MODE_RICH_ASCII() end if
    if term == "sun"                 return MODE_RICH_16()    end if
    if term == "vt100"               return MODE_RICH_16()    end if
    if term == "vt220"               return MODE_RICH_16()    end if
    if term == "sun-color"           return MODE_RICH_TRUE()  end if
    if str.index_of(term, "256color") >= 0
        return MODE_RICH_TRUE()
    end if
    // Hammerhead UEFI framebuffer: kernel doesn't set TERM but tem
    // supports full ANSI/CSI/truecolor. Default to truecolor when we
    // have a tty but no TERM hint.
    if str.length(term) == 0         return MODE_RICH_TRUE()  end if
    // Anything else: safe 16-color baseline.
    return MODE_RICH_16()
end detect_rich_mode_for_main

// SGR escape sequences. ESC char via C helper (Reef lexer has no \x escapes).
// esc_reset returns the SGR reset sequence "\e[0m".
fn esc_reset(): string
    return str.concat(zyginit_esc_str(), "[0m")
end esc_reset

// 16-color foreground codes.
fn sgr_steel(): string  return str.concat(zyginit_esc_str(), "[37m")   end sgr_steel
fn sgr_teal(): string   return str.concat(zyginit_esc_str(), "[36m")   end sgr_teal
fn sgr_ok(): string     return str.concat(zyginit_esc_str(), "[32m")   end sgr_ok
fn sgr_warn(): string   return str.concat(zyginit_esc_str(), "[33m")   end sgr_warn
fn sgr_fail(): string   return str.concat(zyginit_esc_str(), "[31m")   end sgr_fail
fn sgr_mute(): string   return str.concat(zyginit_esc_str(), "[2m")    end sgr_mute

// Truecolor foreground codes.
fn sgr_steel_true(): string return str.concat(zyginit_esc_str(), "[38;2;110;123;139m")  end sgr_steel_true
fn sgr_teal_true(): string  return str.concat(zyginit_esc_str(), "[38;2;0;106;111m")    end sgr_teal_true
fn sgr_ok_true(): string    return str.concat(zyginit_esc_str(), "[38;2;46;139;87m")    end sgr_ok_true
fn sgr_warn_true(): string  return str.concat(zyginit_esc_str(), "[38;2;255;191;0m")    end sgr_warn_true
fn sgr_fail_true(): string  return str.concat(zyginit_esc_str(), "[38;2;200;32;31m")    end sgr_fail_true

// Wrap text in the given palette token, honoring g_mode.
fn paint(token: string, text: string): string
    if g_mode == MODE_PLAIN()  return text  end if
    mut on = ""
    if g_mode == MODE_RICH_TRUE()
        if token == "frame"       on = sgr_steel_true()
        elif token == "accent"    on = sgr_teal_true()
        elif token == "ok"        on = sgr_ok_true()
        elif token == "warn"      on = sgr_warn_true()
        elif token == "fail"      on = sgr_fail_true()
        elif token == "mute"      on = sgr_mute()
        end if
    else
        if token == "frame"       on = sgr_steel()
        elif token == "accent"    on = sgr_teal()
        elif token == "ok"        on = sgr_ok()
        elif token == "warn"      on = sgr_warn()
        elif token == "fail"      on = sgr_fail()
        elif token == "mute"      on = sgr_mute()
        end if
    end if
    return str.concat(str.concat(on, text), esc_reset())
end paint

// Glyphs. Selected by g_mode.
fn glyph_ok(): string
    if g_mode == MODE_RICH_ASCII() return "#"   end if
    if g_mode == MODE_PLAIN()      return "ok"  end if
    return "●"
end glyph_ok

fn glyph_fail(): string
    if g_mode == MODE_RICH_ASCII() return "X"    end if
    if g_mode == MODE_PLAIN()      return "fail" end if
    return "✕"
end glyph_fail

fn glyph_pending(): string
    if g_mode == MODE_RICH_ASCII() return "."       end if
    if g_mode == MODE_PLAIN()      return "pending" end if
    return "·"
end glyph_pending

fn glyph_starting(): string
    if g_mode == MODE_RICH_ASCII() return "o"        end if
    if g_mode == MODE_PLAIN()      return "starting" end if
    return "◉"
end glyph_starting

// Sigil: "[Z]" colored c.accent in rich modes.
fn sigil(): string
    return paint("accent", "[Z]")
end sigil

// Plain-mode line: "  <elapsed-s>  <level>  <event>     <name>  [k=v ...]"
fn fmt_plain_event(elapsed_ms: int, level: string, event: string,
                   name: string, kv: string): string
    let secs = int_to_str(elapsed_ms / 1000)
    // centiseconds: truncate the within-second remainder to 0-99 (2 digits)
    let frac = int_to_str((elapsed_ms % 1000) / 10)
    mut pad = ""
    if str.length(frac) < 2  pad = "0"  end if
    mut line = str.concat("  ", secs)
    line = str.concat(line, ".")
    line = str.concat(line, pad)
    line = str.concat(line, frac)
    line = str.concat(line, "  ")
    line = str.concat(line, level)
    line = str.concat(line, "  ")
    line = str.concat(line, event)
    line = str.concat(line, "  ")
    line = str.concat(line, name)
    if str.length(kv) > 0
        line = str.concat(line, "  ")
        line = str.concat(line, kv)
    end if
    return line
end fmt_plain_event

proc tape_push(elapsed_ms: int, glyph: string, name: string, note: string, active_flag: int)
    let slot = g_tape_head % TAPE_HEIGHT()
    zyginit_tape_set(slot, elapsed_ms, glyph, name, note, active_flag)
    g_tape_head = g_tape_head + 1
    if g_tape_count < TAPE_HEIGHT()
        g_tape_count = g_tape_count + 1
    end if
end tape_push

fn fmt_tape_row(row_elapsed_ms: int, row_glyph: string, row_name: string, row_note: string): string
    let secs = row_elapsed_ms / 1000
    let frac = (row_elapsed_ms % 1000) / 10
    mut sf = int_to_str(frac)
    if str.length(sf) < 2  sf = str.concat("0", sf)  end if
    let elapsed = str.concat(str.concat(int_to_str(secs), "."), sf)
    mut pad = ""
    let pad_n = 6 - str.length(elapsed)
    mut i = 0
    while i < pad_n
        pad = str.concat(pad, " ")
        i = i + 1
    end while
    mut row = str.concat(pad, elapsed)
    row = str.concat(row, "  ")
    row = str.concat(row, row_glyph)
    row = str.concat(row, "  ")
    row = str.concat(row, row_name)
    if str.length(row_note) > 0
        row = str.concat(row, "  ")
        row = str.concat(row, paint("mute", str.concat(str.concat("(", row_note), ")")))
    end if
    return row
end fmt_tape_row

fn make_divider(): string
    mut div = ""
    mut k = 0
    let dlen = g_line_width - 16
    while k < dlen
        div = str.concat(div, "─")
        k = k + 1
    end while
    return div
end make_divider

fn fmt_header(elapsed_ms: int): string
    let secs = elapsed_ms / 1000
    let frac = (elapsed_ms % 1000) / 100
    let elapsed = str.concat(str.concat(int_to_str(secs), "."), str.concat(int_to_str(frac), "s"))
    let phase_label = g_runlevel
    mut out = str.concat("  ", sigil())
    out = str.concat(out, str.concat(" zyginit ", str.concat(version.VERSION(), " · ")))
    out = str.concat(out, paint("frame", phase_label))
    let boot_visually_done = (g_phase == "boot") and
                             ((g_done + g_skipped + g_failed_count) >= g_num_svc) and
                             (g_num_svc > 0)
    if not boot_visually_done
        out = str.concat(out, "   ")
        out = str.concat(out, paint("accent", str.concat("elapsed ", elapsed)))
    end if
    out = str.concat(out, "\n  ")
    out = str.concat(out, paint("frame",
        str.concat(str.concat(int_to_str(g_num_svc), " services · tier "),
        str.concat(str.concat(int_to_str(g_cur_tier), " · "),
        str.concat(str.concat(int_to_str(g_done), " done · "),
        str.concat(str.concat(int_to_str(g_failed_count), " failed · "),
        str.concat(int_to_str(g_skipped), " skipped")))))))
    out = str.concat(out, "\n  ")
    if g_failed_count == 0
        out = str.concat(out, paint("mute", "failed: none"))
    elif g_failed_count == 1
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", g_failed_first),
            str.concat("  exit=", int_to_str(g_failed_first_exit)))))
    else
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", int_to_str(g_failed_count)),
            " services")))
    end if
    out = str.concat(out, "\n  ")
    out = str.concat(out, fmt_divider_gauge(g_done + g_skipped, g_num_svc))
    return out
end fmt_header

// Render the boot/shutdown header's bottom rule as a divider with an
// embedded progress gauge. Replaces make_divider() in fmt_header's
// trailing rule and superseded fmt_progress_bar() (now removed) in
// render_boot_screen. Total visual width =
// g_line_width - 16 (matches make_divider). Brackets + 26-cell inner
// content + equal lpad/rpad of dashes. Narrow-terminal fallback drops
// the brackets and shows just "── NN% ──".
fn fmt_divider_gauge(done: int, total: int): string
    if g_mode == MODE_PLAIN()  return ""  end if

    let total_width = g_line_width - 16
    let bar_width = 20
    let inner_width = 26              // bar(20) + "  "(2) + "NNN%"(4)
    let bracket_width = inner_width + 2   // 28: '[' + inner + ']'

    mut filled = 0
    if total > 0
        filled = (done * bar_width) / total
    end if
    if filled > bar_width  filled = bar_width  end if
    if filled < 0  filled = 0  end if

    mut pct = 0
    if total > 0
        pct = (done * 100) / total
    end if
    if pct > 100  pct = 100  end if
    if pct < 0  pct = 0  end if

    // pct_field: right-aligned 3 cells + '%' = 4 cells. E.g. "  3%", " 31%", "100%".
    let pct_str = int_to_str(pct)
    let pct_len = str.length(pct_str)
    mut pct_field = ""
    mut pp = 0
    while pp < (3 - pct_len)
        pct_field = str.concat(pct_field, " ")
        pp = pp + 1
    end while
    pct_field = str.concat(pct_field, pct_str)
    pct_field = str.concat(pct_field, "%")

    // Narrow-terminal fallback: not enough room for brackets + padding.
    if total_width < bracket_width + 2
        // Emit "── NN% ──" centered in total_width.
        let label = str.concat(" ", str.concat(pct_field, " "))
        let label_len = 1 + 4 + 1   // " " + "NNN%" + " "
        mut pad = 0
        if total_width > label_len
            pad = total_width - label_len
        end if
        let lpad_n = pad / 2
        let rpad_n = pad - lpad_n
        mut out = ""
        mut a = 0
        while a < lpad_n
            out = str.concat(out, "─")
            a = a + 1
        end while
        out = str.concat(out, label)
        a = 0
        while a < rpad_n
            out = str.concat(out, "─")
            a = a + 1
        end while
        return paint("accent", out)
    end if

    // Full layout: lpad + '[' + bar + "  " + pct_field + ']' + rpad
    let pad_total = total_width - bracket_width
    let lpad_n = pad_total / 2
    let rpad_n = pad_total - lpad_n

    // Build the bar. Painting per-cell to support per-mode chars.
    mut bar = ""
    mut i = 0
    while i < bar_width
        if g_mode == MODE_RICH_ASCII()
            if i < filled
                bar = str.concat(bar, "#")
            else
                bar = str.concat(bar, " ")
            end if
        else
            if i < filled
                bar = str.concat(bar, paint("accent", "█"))
            else
                bar = str.concat(bar, paint("mute", "░"))
            end if
        end if
        i = i + 1
    end while

    // Assemble. Brackets, pct, and pad chars all painted "accent".
    mut out = ""
    mut j = 0
    while j < lpad_n
        out = str.concat(out, "─")
        j = j + 1
    end while
    out = paint("accent", out)
    out = str.concat(out, paint("accent", "["))
    out = str.concat(out, bar)
    out = str.concat(out, paint("accent", "  "))
    out = str.concat(out, paint("accent", pct_field))
    out = str.concat(out, paint("accent", "]"))
    mut rpad = ""
    j = 0
    while j < rpad_n
        rpad = str.concat(rpad, "─")
        j = j + 1
    end while
    out = str.concat(out, paint("accent", rpad))
    return out
end fmt_divider_gauge


// Render a single tape row, overriding the stored glyph with the current
// spinner frame when the row's active flag indicates a starting or stopping
// transition (active==1 = forward spinner, active==2 = reverse spinner).
fn fmt_tape_row_at(slot: int): string
    let elapsed_ms = zyginit_tape_get_elapsed(slot)
    let name = zyginit_tape_get_name(slot)
    let note = zyginit_tape_get_note(slot)
    let stored_glyph = zyginit_tape_get_glyph(slot)
    let row_active = zyginit_tape_get_active(slot)
    mut glyph = stored_glyph
    if row_active == 1
        glyph = paint("warn", ui_spinner_frame(false))
    elif row_active == 2
        glyph = paint("warn", ui_spinner_frame(true))
    end if
    return fmt_tape_row(elapsed_ms, glyph, name, note)
end fmt_tape_row_at

// Scan tape for any slot with a non-zero active flag (i.e., a spinner is live).
fn has_active_tape_row(): bool
    mut i = 0
    while i < g_tape_count
        let logical = g_tape_head - 1 - i
        mut slot = logical % TAPE_HEIGHT()
        if slot < 0
            slot = slot + TAPE_HEIGHT()
        end if
        if zyginit_tape_get_active(slot) != 0
            return true
        end if
        i = i + 1
    end while
    return false
end has_active_tape_row

// Find the most-recently-pushed tape slot with a non-zero active flag and
// whose name matches `name`. Returns the slot index or -1 if not found.
fn tape_find_active_by_name(name: string): int
    if g_tape_count == 0
        return 0 - 1
    end if
    mut i = 0
    while i < g_tape_count
        let logical = g_tape_head - 1 - i
        mut slot = logical % TAPE_HEIGHT()
        if slot < 0
            slot = slot + TAPE_HEIGHT()
        end if
        if zyginit_tape_get_active(slot) != 0
            if zyginit_tape_get_name(slot) == name
                return slot
            end if
        end if
        i = i + 1
    end while
    return 0 - 1
end tape_find_active_by_name

fn render_boot_screen(elapsed_ms: int): string
    if g_mode == MODE_PLAIN()
        return ""
    end if
    mut out = str.concat(fmt_header(elapsed_ms), "\n")
    let start = g_tape_head - g_tape_count
    mut i = 0
    while i < TAPE_HEIGHT()
        if i < g_tape_count
            let slot = (start + i) % TAPE_HEIGHT()
            out = str.concat(out, fmt_tape_row_at(slot))
        end if
        if i < (TAPE_HEIGHT() - 1)
            out = str.concat(out, "\n")
        end if
        i = i + 1
    end while
    // No trailing newline: total height is exactly g_screen_rows. A trailing
    // \n would advance the cursor past the bottom edge and scroll the [Z]
    // banner off the top of the screen. The progress gauge lives in the
    // header rule (see fmt_divider_gauge), not on the last row.
    return out
end render_boot_screen

// Advance the tick counter and, if in rich mode with an active spinner, redraw.
proc ui_tick()
    g_tick = g_tick + 1
    if g_mode == MODE_PLAIN()  return  end if
    if not has_active_tape_row()  return  end if
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    print(render_boot_screen(elapsed))
end ui_tick

// Rich-mode-only redraw. Plain mode emits its own line before calling this.
proc emit_redraw(elapsed_ms: int)
    if g_mode == MODE_PLAIN()  return  end if
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    print(render_boot_screen(elapsed_ms))
end emit_redraw

proc ui_boot_start(num_svc: int, num_tiers: int, runlevel: string)
    g_phase = "boot"
    g_runlevel = runlevel
    g_num_svc = num_svc
    g_num_tiers = num_tiers
    g_cur_tier = 0
    g_done = 0
    g_failed_count = 0
    g_skipped = 0
    g_failed_first = ""
    g_failed_first_exit = 0
    g_tape_head = 0
    g_tape_count = 0
    zyginit_tape_clear()
    g_boot_start_ms = zyginit_monotonic_ms()
end ui_boot_start

proc ui_tier_start(tier: int)
    g_cur_tier = tier
end ui_tier_start

proc ui_tier_done(tier: int)
    // header repaints happen via emit_redraw on next event/tick
end ui_tier_done

// dur_ms: service's own runtime (from supervisor). Reserved for future
// use (Task 6 spinner display); the tape currently shows wall-clock
// elapsed since boot, not per-service duration.
proc ui_event_started(name: string, dur_ms: int)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_done = g_done + 1
    let slot = tape_find_active_by_name(name)
    if slot >= 0
        // Update the existing active row in place
        zyginit_tape_set_glyph(slot, paint("ok", glyph_ok()))
        zyginit_tape_set_note(slot, "")
        zyginit_tape_set_active(slot, 0)
    else
        // No prior starting row — push a fresh static row
        tape_push(elapsed, paint("ok", glyph_ok()), name, "", 0)
    end if
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "started", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_started

// dur_ms: service's own runtime (from supervisor). Reserved for future
// use (Task 6 spinner display); the tape currently shows wall-clock
// elapsed since boot, not per-service duration.
proc ui_event_failed(name: string, exit_code: int, dur_ms: int)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_done = g_done + 1
    g_failed_count = g_failed_count + 1
    if g_failed_count == 1
        g_failed_first = name
        g_failed_first_exit = exit_code
    end if
    let exit_kv = str.concat("exit=", int_to_str(exit_code))
    let slot = tape_find_active_by_name(name)
    if slot >= 0
        zyginit_tape_set_glyph(slot, paint("fail", glyph_fail()))
        zyginit_tape_set_note(slot, exit_kv)
        zyginit_tape_set_active(slot, 0)
    else
        tape_push(elapsed, paint("fail", glyph_fail()), name, exit_kv, 0)
    end if
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "err", "failed", name, exit_kv))
    else
        emit_redraw(elapsed)
    end if
end ui_event_failed

// Called when a service is transitioning to started (forward spinner visible).
proc ui_event_starting(name: string)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    // active=1: forward spinner (starting)
    tape_push(elapsed, paint("warn", ui_spinner_frame(false)), name, "", 1)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "starting", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_starting

// Called when a service is transitioning to stopped (reverse spinner visible).
proc ui_event_stopping(name: string)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    // active=2: reverse spinner (stopping)
    tape_push(elapsed, paint("warn", ui_spinner_frame(true)), name, "", 2)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "stopping", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_stopping

// Called when a service's [condition] block fails and the service is skipped
// (STATE_SKIPPED). No process is ever forked; the service is counted as done
// for progress purposes but not as online or failed.
proc ui_event_skipped(name: string, reason: string)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_skipped = g_skipped + 1
    let note = str.concat("skipped: ", reason)
    tape_push(elapsed, paint("mute", glyph_pending()), name, note, 0)
    if g_mode == MODE_PLAIN()
        let kv = str.concat("reason=", reason)
        println(fmt_plain_event(elapsed, "info", "skipped", name, kv))
    else
        emit_redraw(elapsed)
    end if
end ui_event_skipped

proc ui_init(rich_mode: int)
    g_mode = rich_mode
    g_failed = false
end ui_init

// Detect terminal size via TIOCGWINSZ and update g_tape_height / g_line_width.
// Called from main.reef after setup_pid1_console() (so fd 1 = /dev/console)
// and before ui_boot_start().
// When ZYGINIT_FORCE_80x25 is set (integration / snapshot tests), lock to
// 80x25 so snapshot output is deterministic regardless of the host terminal.
proc ui_detect_winsize()
    if env.has_env("ZYGINIT_FORCE_80x25")
        g_screen_rows = 25
        g_screen_cols = 80
    else
        let rows = new [int](1)
        let cols = new [int](1)
        rows[0] = 25
        cols[0] = 80
        if zyginit_get_winsize(1, rows, cols) == 0
            g_screen_rows = rows[0]
            g_screen_cols = cols[0]
        end if
    end if
    // Tape height = screen rows - (header 4 rows including gauge divider).
    // Gauge lives inside the header, not on a separate trailing row.
    g_tape_height = g_screen_rows - 4
    if g_tape_height < 4
        g_tape_height = 4
    end if
    if g_tape_height > 32
        g_tape_height = 32
    end if
    // Line width = cols - 2 (1-char margin each side)
    g_line_width = g_screen_cols - 2
    if g_line_width < 40
        g_line_width = 40
    end if
end ui_detect_winsize

fn ui_mode(): int
    return g_mode
end ui_mode

fn ui_runlevel(): string
    return g_runlevel
end ui_runlevel

proc ui_set_mode(m: int)
    g_mode = m
end ui_set_mode

proc ui_boot_complete(stats: BootStats)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(stats.elapsed_ms, "info", "boot_complete",
                "summary", str.concat(str.concat("online=", int_to_str(stats.online)),
                           str.concat(str.concat(" failed=", int_to_str(stats.failed)),
                                      str.concat(" skipped=", int_to_str(stats.skipped))))))
        return
    end if
    // Clear screen, paint final card.
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    let secs = stats.elapsed_ms / 1000
    let frac = (stats.elapsed_ms % 1000) / 100
    let elapsed = str.concat(str.concat(int_to_str(secs), "."),
                             str.concat(int_to_str(frac), "s"))
    let summary_count = int_to_str(stats.online + stats.failed + stats.skipped)
    mut out = str.concat("  ", sigil())
    out = str.concat(out, str.concat(" zyginit ", str.concat(version.VERSION(), " · ")))
    out = str.concat(out, paint("frame", g_runlevel))
    out = str.concat(out, "   ")
    out = str.concat(out, paint("accent", str.concat("boot ", elapsed)))
    out = str.concat(out, "\n")
    out = str.concat(out, "  ")
    out = str.concat(out, paint("frame",
        str.concat(str.concat(summary_count, " services — "),
        str.concat(str.concat(int_to_str(stats.online), " online, "),
        str.concat(str.concat(int_to_str(stats.failed), " failed, "),
        str.concat(int_to_str(stats.skipped), " skipped"))))))
    out = str.concat(out, "\n\n")
    if stats.failed == 0
        out = str.concat(out, "  ")
        out = str.concat(out, paint("ok", "all services online"))
        out = str.concat(out, "\n")
    elif stats.failed == 1
        out = str.concat(out, "  ")
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", g_failed_first),
            str.concat("  exit=", int_to_str(g_failed_first_exit)))))
        out = str.concat(out, "\n")
        out = str.concat(out, "      ")
        out = str.concat(out, paint("accent",
            str.concat("→ zygctl log ", g_failed_first)))
        out = str.concat(out, paint("mute", "    to see why"))
        out = str.concat(out, "\n")
    else
        out = str.concat(out, "  ")
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", int_to_str(stats.failed)), " services")))
        out = str.concat(out, "\n")
        out = str.concat(out, "      ")
        out = str.concat(out, paint("accent", "→ zygctl status"))
        out = str.concat(out, paint("mute", "    to see them"))
        out = str.concat(out, "\n")
    end if
    out = str.concat(out, "  ")
    out = str.concat(out, paint("accent", make_divider()))
    out = str.concat(out, "\n")
    // Slowest line
    let slow_n = stats.slowest_count
    if slow_n > 0
        mut slow = "slowest:"
        mut i = 0
        mut max = slow_n
        if max > 3
            max = 3
        end if
        while i < max
            slow = str.concat(slow, "  ")
            slow = str.concat(slow, stats.slowest[i])
            i = i + 1
        end while
        out = str.concat(out, "  ")
        out = str.concat(out, paint("frame", slow))
        out = str.concat(out, "\n")
    end if
    print(out)
end ui_boot_complete

proc ui_shutdown_start(reason: string)
    g_phase = "shutdown"
    g_shutdown_reason = reason
    g_runlevel = str.concat("stopping for ", reason)
    g_done = 0
    g_failed_count = 0
    g_skipped = 0
    g_failed_first = ""
    g_failed_first_exit = 0
    g_tape_head = 0
    g_tape_count = 0
    g_boot_start_ms = zyginit_monotonic_ms()
end ui_shutdown_start

proc ui_event_stopped(name: string, dur_ms: int)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_done = g_done + 1
    let slot = tape_find_active_by_name(name)
    if slot >= 0
        zyginit_tape_set_glyph(slot, paint("mute", glyph_pending()))
        zyginit_tape_set_note(slot, "")
        zyginit_tape_set_active(slot, 0)
    else
        tape_push(elapsed, paint("mute", glyph_pending()), name, "", 0)
    end if
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "stopped", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_stopped

proc ui_shutdown_complete(reason: string, elapsed_ms: int)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed_ms, "info", "shutdown_complete",
                reason, str.concat("down=", int_to_str(g_done))))
        return
    end if
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    let secs = elapsed_ms / 1000
    let frac = (elapsed_ms % 1000) / 100
    let elapsed = str.concat(str.concat(int_to_str(secs), "."),
                             str.concat(int_to_str(frac), "s"))
    mut out = str.concat("  ", sigil())
    out = str.concat(out, str.concat(" zyginit ", str.concat(version.VERSION(), " · ")))
    out = str.concat(out, paint("frame", str.concat(reason, " complete")))
    out = str.concat(out, "   ")
    out = str.concat(out, paint("accent", str.concat(str.concat(reason, " "), elapsed)))
    out = str.concat(out, "\n  ")
    mut stat_str = "stopped cleanly"
    if g_failed_count > 0
        stat_str = str.concat(str.concat("stopped (", int_to_str(g_failed_count)), " force-killed)")
    end if
    out = str.concat(out, paint("frame",
        str.concat(str.concat(int_to_str(g_num_svc), " services "), stat_str)))
    out = str.concat(out, "\n  ")
    out = str.concat(out, paint("accent", make_divider()))
    out = str.concat(out, "\n  ")
    out = str.concat(out, paint("mute", "invoking uadmin(A_SHUTDOWN, AD_BOOT)"))
    out = str.concat(out, "\n")
    print(out)
end ui_shutdown_complete

// Scenario dispatcher for --ui-demo. Called from main.reef.
// Returns 0 on success, 1 if the scenario name is unknown.
fn ui_demo(scenario: string): int
    if scenario == "skeleton"
        println("ui.reef skeleton ok, mode=" + int_to_str(g_mode))
        return 0
    end if
    if scenario == "plain_boot"
        println(fmt_plain_event(40, "info", "started", "root-fs", ""))
        println(fmt_plain_event(120, "info", "started", "crypto", "dur_ms=80"))
        println(fmt_plain_event(310, "info", "started", "devfs", "dur_ms=190"))
        println(fmt_plain_event(5020, "err",  "failed",  "network", "exit=1 dur_ms=4023"))
        return 0
    end if
    if str.index_of(scenario, "detect_") == 0
        g_mode = detect_rich_mode()
        println("mode=" + int_to_str(g_mode))
        return 0
    end if
    if scenario == "palette_true" or scenario == "palette_16"
        g_mode = detect_rich_mode()
        println(paint("frame",  "frame text"))
        println(paint("accent", "accent text"))
        println(paint("ok",     "ok text"))
        println(paint("warn",   "warn text"))
        println(paint("fail",   "fail text"))
        println(paint("mute",   "mute text"))
        return 0
    end if
    if scenario == "glyphs_unicode" or scenario == "glyphs_ascii"
        g_mode = detect_rich_mode()
        println(glyph_ok() + " " + glyph_starting() + " " +
                glyph_fail() + " " + glyph_pending())
        return 0
    end if
    if scenario == "sigil_rich"
        g_mode = detect_rich_mode()
        println(sigil() + " zyginit " + version.VERSION())
        return 0
    end if
    if scenario == "boot_tape_rich" or scenario == "boot_tape_ascii" or scenario == "boot_tape_plain"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        g_boot_start_ms = 0
        let names = new [string](9)
        names[0] = "root-fs"
        names[1] = "crypto"
        names[2] = "devfs"
        names[3] = "swap"
        names[4] = "filesystem"
        names[5] = "identity"
        names[6] = "sysconfig"
        names[7] = "dlmgmtd"
        names[8] = "network"
        let elapsed_seq = new [int](9)
        elapsed_seq[0] = 40
        elapsed_seq[1] = 160
        elapsed_seq[2] = 310
        elapsed_seq[3] = 490
        elapsed_seq[4] = 1040
        elapsed_seq[5] = 1080
        elapsed_seq[6] = 1360
        elapsed_seq[7] = 1550
        elapsed_seq[8] = 5020
        mut i = 0
        while i < 8
            g_done = g_done + 1
            tape_push(elapsed_seq[i], paint("ok", glyph_ok()), names[i], "", 0)
            i = i + 1
        end while
        g_failed_count = 1
        g_failed_first = "network"
        g_failed_first_exit = 1
        g_cur_tier = 5
        g_done = g_done + 1
        tape_push(5020, paint("fail", glyph_fail()), "network", "exit=1", 0)
        if g_mode == MODE_PLAIN()
            let lvls = new [string](9)
            let evs = new [string](9)
            let kvs = new [string](9)
            mut j = 0
            while j < 8
                lvls[j] = "info"
                evs[j] = "started"
                kvs[j] = ""
                j = j + 1
            end while
            lvls[8] = "err"
            evs[8] = "failed"
            kvs[8] = "exit=1"
            mut k = 0
            while k < 9
                println(fmt_plain_event(elapsed_seq[k], lvls[k], evs[k], names[k], kvs[k]))
                k = k + 1
            end while
        else
            print(render_boot_screen(5020))
        end if
        return 0
    end if
    if scenario == "progress_rich" or scenario == "progress_ascii"
        if scenario == "progress_ascii"
            g_mode = MODE_RICH_ASCII()
        else
            g_mode = detect_rich_mode()
            if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        end if
        ui_detect_winsize()
        ui_boot_start(17, 8, "multi-user")
        g_done = 12
        g_failed_count = 1
        println(fmt_divider_gauge(g_done + g_skipped, g_num_svc))
        return 0
    end if
    if scenario == "progress_full"
        g_mode = detect_rich_mode()
        if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        ui_detect_winsize()
        ui_boot_start(17, 8, "multi-user")
        g_done = 17
        println(fmt_divider_gauge(g_done + g_skipped, g_num_svc))
        return 0
    end if
    if scenario == "gauge_live_31" or scenario == "gauge_live_31_ascii"
        if scenario == "gauge_live_31_ascii"
            g_mode = MODE_RICH_ASCII()
        else
            g_mode = detect_rich_mode()
            if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        end if
        ui_detect_winsize()
        println(fmt_divider_gauge(31, 100))
        return 0
    end if
    if scenario == "gauge_live_100"
        g_mode = detect_rich_mode()
        if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        ui_detect_winsize()
        println(fmt_divider_gauge(100, 100))
        return 0
    end if
    if scenario == "gauge_live_0"
        g_mode = detect_rich_mode()
        if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        ui_detect_winsize()
        println(fmt_divider_gauge(0, 100))
        return 0
    end if
    if scenario == "spinner_forward"
        g_mode = detect_rich_mode()
        mut i = 0
        while i < 8
            g_tick = i
            print(ui_spinner_frame(false))
            i = i + 1
        end while
        println("")
        return 0
    end if
    if scenario == "spinner_reverse"
        g_mode = detect_rich_mode()
        mut i = 0
        while i < 8
            g_tick = i
            print(ui_spinner_frame(true))
            i = i + 1
        end while
        println("")
        return 0
    end if
    if scenario == "spinner_in_tape"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        g_boot_start_ms = 0
        tape_push(40, paint("ok", glyph_ok()), "root-fs", "", 0)
        tape_push(160, paint("ok", glyph_ok()), "crypto", "", 0)
        tape_push(310, paint("ok", glyph_ok()), "devfs", "", 0)
        g_done = 3
        // Push the network row with active=1 (forward spinner).
        // Bypass ui_event_starting to avoid a host-dependent monotonic_ms()
        // reading in the demo.
        g_tick = 0
        tape_push(2100, paint("warn", ui_spinner_frame(false)), "network", "", 1)
        // Now bump tick so the live re-render shows frame index 2.
        g_tick = 2
        print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
              str.concat(zyginit_esc_str(), "[H")))
        print(render_boot_screen(2100))
        return 0
    end if
    if scenario == "final_card_ok"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        let slow = new [string](3)
        slow[0] = "dlmgmtd 1.2s"
        slow[1] = "filesystem 0.55s"
        slow[2] = "sshd 0.37s"
        let stats = BootStats{
            elapsed_ms: 8300,
            online: 17,
            failed: 0,
            skipped: 0,
            slowest: slow,
            slowest_count: 3
        }
        ui_boot_complete(stats)
        return 0
    end if
    if scenario == "final_card_failed"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        g_failed_first = "network"
        g_failed_first_exit = 1
        let slow = new [string](3)
        slow[0] = "network 5.02s"
        slow[1] = "filesystem 0.55s"
        slow[2] = "sshd 0.37s"
        let stats = BootStats{
            elapsed_ms: 8300,
            online: 16,
            failed: 1,
            skipped: 0,
            slowest: slow,
            slowest_count: 3
        }
        ui_boot_complete(stats)
        return 0
    end if
    if scenario == "shutdown_mirror"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        ui_shutdown_start("reboot")
        g_boot_start_ms = 0
        tape_push(40,  paint("mute", glyph_pending()), "sshd", "", 0)
        tape_push(160, paint("mute", glyph_pending()), "console-login", "", 0)
        tape_push(310, paint("mute", glyph_pending()), "cron", "", 0)
        // active=2: reverse spinner (stopping)
        g_tick = 0
        tape_push(480, paint("warn", ui_spinner_frame(true)), "syslogd", "", 2)
        g_tick = 3
        g_done = 4
        g_cur_tier = 6
        print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
              str.concat(zyginit_esc_str(), "[H")))
        print(render_boot_screen(480))
        return 0
    end if
    if scenario == "shutdown_final"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        ui_shutdown_start("reboot")
        g_num_svc = 17
        g_done = 17
        ui_shutdown_complete("reboot", 2100)
        return 0
    end if
    if scenario == "task_ok"
        g_mode = detect_rich_mode()
        ui_boot_start(5, 2, "multi-user")
        g_boot_start_ms = 0
        tape_push(40,  paint("ok", glyph_ok()), "root-fs",  "", 0)
        tape_push(160, paint("ok", glyph_ok()), "task-svc", "", 0)
        g_done = 2
        let slow_tok = new [string](3)
        let stats_tok = BootStats{
            elapsed_ms: 200,
            online: 5,
            failed: 0,
            skipped: 0,
            slowest: slow_tok,
            slowest_count: 0
        }
        ui_boot_complete(stats_tok)
        return 0
    end if

    if scenario == "task_failed"
        g_mode = detect_rich_mode()
        ui_boot_start(5, 2, "multi-user")
        g_boot_start_ms = 0
        tape_push(40,  paint("ok",   glyph_ok()),   "root-fs",  "", 0)
        tape_push(160, paint("fail", glyph_fail()), "task-svc", "exit=1", 0)
        g_done = 2
        g_failed_count = 1
        g_failed_first = "task-svc"
        g_failed_first_exit = 1
        let slow_tf = new [string](3)
        let stats_tf = BootStats{
            elapsed_ms: 200,
            online: 4,
            failed: 1,
            skipped: 0,
            slowest: slow_tf,
            slowest_count: 0
        }
        ui_boot_complete(stats_tf)
        return 0
    end if

    if scenario == "boot_with_skipped"
        g_mode = detect_rich_mode()
        ui_boot_start(5, 2, "multi-user")
        g_boot_start_ms = 0
        tape_push(40,  paint("ok",   glyph_ok()),      "root-fs", "", 0)
        tape_push(160, paint("mute", glyph_pending()), "acpihpd", "skipped: missing /dev/acpihp", 0)
        tape_push(310, paint("ok",   glyph_ok()),      "cron",    "", 0)
        g_done = 2
        g_skipped = 1
        print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
              str.concat(zyginit_esc_str(), "[H")))
        print(render_boot_screen(400))
        return 0
    end if

    if scenario == "final_card_with_skipped"
        g_mode = detect_rich_mode()
        ui_boot_start(23, 9, "multi-user")
        let slow_fcs = new [string](3)
        let stats_fcs = BootStats{
            elapsed_ms: 8300,
            online: 19,
            failed: 0,
            skipped: 4,
            slowest: slow_fcs,
            slowest_count: 0
        }
        ui_boot_complete(stats_fcs)
        return 0
    end if

    if scenario == "status_skipped"
        // status_skipped requires zygctl status table rendering with a
        // SKIPPED row. The existing --ui-demo infrastructure doesn't yet
        // build a ServiceTable mock that ui_render.ui_render_status can
        // render. Deferred — emit a placeholder note so the test exists
        // and tracks the gap.
        g_mode = detect_rich_mode()
        println("status_skipped: deferred — zygctl status snapshot via --ui-demo not yet supported")
        return 0
    end if

    println("ui.reef: unknown demo scenario: " + scenario)
    return 1
end ui_demo

fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

// ============================================================================
// Status/list rendering (used by socket command handlers)
// ============================================================================

fn pad_right(s: string, n: int): string
    let extra = n - str.length(s)
    if extra <= 0
        return s
    end if
    mut out = s
    mut i = 0
    while i < extra
        out = str.concat(out, " ")
        i = i + 1
    end while
    return out
end pad_right

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: ui_render.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Status/list table rendering for zygctl status and list commands.
             Separated from ui.reef to avoid a circular dependency with supervisor.

******************************************************************************/

module ui_render

import ui
import supervisor
import config
import version
import core.str as str
import time.time as time

export
    fn ui_render_status(table: supervisor.ServiceTable, want_banner: int, plain: int): string
    fn ui_render_status_one(table: supervisor.ServiceTable, idx: int, plain: int): string
    fn ui_render_list(table: supervisor.ServiceTable, plain: int): string
end export

// ============================================================================
// Helpers
// ============================================================================

fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

// Helper: return the palette token ("ok"/"warn"/"fail"/"mute") for a state.
fn state_color(state: int): string
    if state == supervisor.STATE_RUNNING()     return "ok"   end if
    if state == supervisor.STATE_STARTING()    return "warn" end if
    if state == supervisor.STATE_STOPPING()    return "warn" end if
    if state == supervisor.STATE_STOPPED()     return "mute" end if
    if state == supervisor.STATE_FAILED()      return "fail" end if
    if state == supervisor.STATE_MAINTENANCE() return "fail" end if
    if state == supervisor.STATE_DISABLED()    return "mute" end if
    if state == supervisor.STATE_WAITING()     return "warn" end if
    if state == supervisor.STATE_SKIPPED()     return "mute" end if
    return "mute"
end state_color

// Helper: return the raw glyph character for a state (no paint wrapping).
fn state_glyph(state: int): string
    if state == supervisor.STATE_RUNNING()     return ui.glyph_ok()       end if
    if state == supervisor.STATE_STARTING()    return ui.glyph_starting() end if
    if state == supervisor.STATE_STOPPING()    return ui.glyph_starting() end if
    if state == supervisor.STATE_STOPPED()     return ui.glyph_pending()  end if
    if state == supervisor.STATE_FAILED()      return ui.glyph_fail()     end if
    if state == supervisor.STATE_MAINTENANCE() return ui.glyph_fail()     end if
    if state == supervisor.STATE_DISABLED()    return ui.glyph_pending()  end if
    if state == supervisor.STATE_WAITING()     return ui.glyph_starting() end if
    if state == supervisor.STATE_SKIPPED()     return ui.glyph_pending()  end if
    return "?"
end state_glyph

// Helper: return the label string for a state (leading space, no glyph).
fn state_label(state: int): string
    if state == supervisor.STATE_RUNNING()     return " running"  end if
    if state == supervisor.STATE_STARTING()    return " starting" end if
    if state == supervisor.STATE_STOPPING()    return " stopping" end if
    if state == supervisor.STATE_STOPPED()     return " stopped"  end if
    if state == supervisor.STATE_FAILED()      return " failed"   end if
    if state == supervisor.STATE_MAINTENANCE() return " maint."   end if
    if state == supervisor.STATE_DISABLED()    return " disabled" end if
    if state == supervisor.STATE_WAITING()     return " waiting"  end if
    if state == supervisor.STATE_SKIPPED()     return " skipped"  end if
    return " ?"
end state_label

// Compute the SERVICE column width for status tables.
// Scans all service names and returns the widest + 2 padding, clamped to [12, 24].
// The "SERVICE" header is 7 chars; we use that as the floor before clamping.
fn compute_service_col_width(table: supervisor.ServiceTable): int
    let count = supervisor.service_count(table)
    mut max_len = 7   // "SERVICE" header length
    mut i = 0
    while i < count
        let rt = supervisor.get_runtime(table, i)
        let def = supervisor.rt_def(rt)
        let name = config.svc_name(def)
        let n = str.length(name)
        if n > max_len
            max_len = n
        end if
        i = i + 1
    end while
    // Clamp: 12 minimum (visual stability), 24 maximum (avoid eating other columns)
    if max_len < 12
        max_len = 12
    end if
    if max_len > 24
        max_len = 24
    end if
    return max_len + 2   // 2 cols of padding after the name
end compute_service_col_width

fn fmt_status_row(table: supervisor.ServiceTable, idx: int, name_col_width: int): string
    let rt = supervisor.get_runtime(table, idx)
    let def = supervisor.rt_def(rt)
    let name = config.svc_name(def)
    let state = supervisor.rt_state(rt)
    let pid = supervisor.rt_pid(rt)
    let ctid = supervisor.rt_contract_id(rt)
    mut row = str.concat("  ", ui.pad_right(name, name_col_width))
    // STATE column: paint only the glyph, then pad the label so ANSI escapes
    // don't inflate the byte count and shift downstream columns.
    let glyph_color = state_color(state)
    let g = state_glyph(state)
    let label = state_label(state)
    row = str.concat(row, ui.paint(glyph_color, g))
    row = str.concat(row, ui.pad_right(label, 10))
    if pid > 0
        row = str.concat(row, ui.pad_right(int_to_str(pid), 7))
    else
        row = str.concat(row, ui.pad_right("", 7))
    end if
    if ctid > 0
        row = str.concat(row, ui.pad_right(int_to_str(ctid), 7))
    else
        row = str.concat(row, ui.pad_right("", 7))
    end if
    // Uptime: only for RUNNING with a valid start time
    let last_start = supervisor.rt_last_start_time(rt)
    if state == supervisor.STATE_RUNNING() and last_start > 0
        let uptime_s = time.time_now() - last_start
        row = str.concat(row, ui.pad_right(supervisor.format_duration(uptime_s), 10))
    else
        row = str.concat(row, ui.pad_right("", 10))
    end if
    // Notes column: exit code and restart count
    mut notes = ""
    let last_exit = supervisor.rt_last_exit_code(rt)
    let restart_count = supervisor.rt_restart_count(rt)
    let reason = supervisor.rt_skip_reason(rt)
    if state == supervisor.STATE_SKIPPED() and str.length(reason) > 0
        notes = reason
    elif state == supervisor.STATE_FAILED() and str.length(reason) > 0
        notes = reason
    elif last_exit >= 0 and state != supervisor.STATE_RUNNING() and state != supervisor.STATE_WAITING()
        notes = str.concat("exit=", int_to_str(last_exit))
        if restart_count > 0
            notes = str.concat(notes, str.concat(" restarts=", int_to_str(restart_count)))
        end if
    elif restart_count > 0
        notes = str.concat("restarts=", int_to_str(restart_count))
    end if
    row = str.concat(row, notes)
    return row
end fmt_status_row

// ============================================================================
// Public render functions
// ============================================================================

fn ui_render_status(table: supervisor.ServiceTable,
                    want_banner: int, plain: int): string
    let prev_mode = ui.ui_mode()
    // Mode source: when plain=1 the client requested no escapes (always
    // honored). When plain=0, the daemon's own g_mode (set at startup
    // by TTY/term detection) determines rendering. Task 10 ensures the
    // client only sends a bare STATUS/LIST when its own stdout is rich.
    if plain != 0
        ui.ui_set_mode(ui.MODE_PLAIN())
    end if
    let count = supervisor.service_count(table)
    // Summary counts
    mut online = 0
    mut failed = 0
    mut skipped = 0
    mut i = 0
    while i < count
        let rt = supervisor.get_runtime(table, i)
        let st = supervisor.rt_state(rt)
        if st == supervisor.STATE_RUNNING()
            online = online + 1
        elif st == supervisor.STATE_STOPPED()
            // A oneshot that exited 0 is "done and online" from the system's perspective.
            let rt2 = supervisor.get_runtime(table, i)
            if supervisor.rt_last_exit_code(rt2) == 0
                online = online + 1
            end if
        elif st == supervisor.STATE_FAILED() or st == supervisor.STATE_MAINTENANCE()
            failed = failed + 1
        elif st == supervisor.STATE_SKIPPED()
            skipped = skipped + 1
        end if
        i = i + 1
    end while
    let name_col = compute_service_col_width(table)
    mut out = ""
    if want_banner != 0 and ui.ui_mode() != ui.MODE_PLAIN()
        let rl = ui.ui_runlevel()
        let rl_str = if str.length(rl) > 0 then rl else "running" end if
        out = str.concat(out, "  ")
        out = str.concat(out, ui.sigil())
        out = str.concat(out, str.concat(" zyginit ", str.concat(version.VERSION(), " · ")))
        out = str.concat(out, ui.paint("frame",
            str.concat(str.concat(rl_str, " · "), str.concat(int_to_str(count),
            str.concat(" services · ",
            str.concat(int_to_str(online),
            str.concat(" online, ",
            str.concat(str.concat(int_to_str(failed), " failed, "),
            str.concat(int_to_str(skipped), " skipped")))))))))
        out = str.concat(out, "\n  ")
        out = str.concat(out, ui.paint("accent", ui.make_divider()))
        out = str.concat(out, "\n")
    end if
    // Column header
    out = str.concat(out, "  ")
    let header_text = str.concat(ui.pad_right("SERVICE", name_col),
                     str.concat(ui.pad_right("STATE", 11),
                     str.concat(ui.pad_right("PID", 7),
                     str.concat(ui.pad_right("CTID", 7),
                     str.concat(ui.pad_right("UPTIME", 10), "NOTES")))))
    out = str.concat(out, ui.paint("frame", header_text))
    out = str.concat(out, "\n")
    // Rows
    mut j = 0
    while j < count
        out = str.concat(out, fmt_status_row(table, j, name_col))
        out = str.concat(out, "\n")
        j = j + 1
    end while
    ui.ui_set_mode(prev_mode)
    return out
end ui_render_status

fn ui_render_status_one(table: supervisor.ServiceTable, idx: int, plain: int): string
    let prev_mode = ui.ui_mode()
    if plain != 0
        ui.ui_set_mode(ui.MODE_PLAIN())
    end if
    let name_col = compute_service_col_width(table)
    let row = str.concat(fmt_status_row(table, idx, name_col), "\n")
    ui.ui_set_mode(prev_mode)
    return row
end ui_render_status_one

fn ui_render_list(table: supervisor.ServiceTable, plain: int): string
    let prev_mode = ui.ui_mode()
    if plain != 0
        ui.ui_set_mode(ui.MODE_PLAIN())
    end if
    let count = supervisor.service_count(table)
    if count == 0
        ui.ui_set_mode(prev_mode)
        return "no services loaded\n"
    end if
    mut out = ""
    mut i = 0
    while i < count
        let rt = supervisor.get_runtime(table, i)
        let def = supervisor.rt_def(rt)
        let name = config.svc_name(def)
        let stype = config.service_type_name(config.svc_type(def))
        let chip = ui.paint("accent", stype)
        out = str.concat(out, name)
        out = str.concat(out, " (")
        out = str.concat(out, chip)
        out = str.concat(out, ", enabled)\n")
        i = i + 1
    end while
    ui.ui_set_mode(prev_mode)
    return out
end ui_render_list

end module
/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: version.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Generated version constant. Do not edit by hand — regenerated
             by scripts/bump-version.sh.

******************************************************************************/

module version

export
    fn VERSION(): string
end export

fn VERSION(): string
    return "0.2.7"
end VERSION

end module