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

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

    Project: repoman
   Filename: src/incus.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Wrappers over the incus CLI (launch, delete, profile ops, device add with shift)
     
******************************************************************************/

module incus

import core.str
import sys.process as p
import sys.fd as fd
import core.result_generic as rg
import core.convert as convert

export
    type CaptureResult
    fn process_run_capture(program: string, args: [string]): CaptureResult
    fn process_run_silent(program: string, args: [string]): int
    fn validate_name(name: string): bool
    fn project_ensure(project: string, verbose: bool): rg.Result[bool, string]
    fn project_present(project: string): rg.Result[bool, string]
    fn container_exists(project: string, name: string, verbose: bool): rg.Result[bool, string]
    fn launch(project: string, name: string, image: string, profiles: [string]): rg.Result[bool, string]
    fn device_add_disk(project: string, name: string, dev: string, src: string, dst: string): rg.Result[bool, string]
    fn set_env_var(project: string, name: string, key: string, val: string): rg.Result[bool, string]
    fn restart(project: string, name: string): rg.Result[bool, string]
    fn container_state(project: string, name: string): rg.Result[string, string]
    fn delete_container(project: string, name: string): rg.Result[bool, string]
    fn delete_profile(project: string, name: string): rg.Result[bool, string]
    fn host_uid(): rg.Result[string, string]
    fn profile_exists(project: string, name: string): rg.Result[bool, string]
    fn profile_create_or_edit(project: string, name: string, yaml: string): rg.Result[bool, string]
    fn profile_get(project: string, name: string): rg.Result[string, string]
    fn device_add_disk_opts(project: string, name: string, dev: string, src: string, dst: string, opts: [string]): rg.Result[bool, string]
end export

// Spawn a program with both stdout and stderr redirected to /dev/null in the
// child. Used for existence-check probes where the upstream command's error
// output would confuse the user (e.g., `incus project show foo` writing
// "Error: Project not found" to stderr when foo doesn't exist — we already
// know that, the missing-ness is the signal we wanted).
//
// Implementation: fork → in child, open /dev/null and dup2 it over fd 1/2,
// then exec the program. Returns the child PID; caller waits as usual.
fn process_run_silent(program: string, args: [string]): int
    let pid: int = p.process_fork()
    if pid < 0
        return -1
    end if
    if pid == 0
        let dev_null: int = fd.fd_open("/dev/null", fd.O_WRONLY(), 0)
        if dev_null >= 0
            let _o: int = fd.fd_dup2(dev_null, fd.STDOUT())
            let _e: int = fd.fd_dup2(dev_null, fd.STDERR())
            let _c: int = fd.fd_close(dev_null)
        end if
        let _x: int = p.process_run_exec(program, args)
        p.exit_now(127)
    end if
    return pid
end process_run_silent

type CaptureResult = struct
    exit_code: int
    stdout: string
end CaptureResult

// Spawn `program args` and capture the child's stdout to a string.
// stderr passes through to parent terminal. Returns exit code + stdout.
// On any setup failure (fork, pipe, exec), exit_code is non-zero and
// stdout is empty.
fn process_run_capture(program: string, args: [string]): CaptureResult
    let pipe_fds: [int] = fd.fd_pipe()
    if pipe_fds.length() != 2
        return CaptureResult { exit_code: -1, stdout: "" }
    end if
    let read_fd: int = pipe_fds[0]
    let write_fd: int = pipe_fds[1]

    let pid: int = p.process_fork()
    if pid < 0
        let _r: int = fd.fd_close(read_fd)
        let _w: int = fd.fd_close(write_fd)
        return CaptureResult { exit_code: -1, stdout: "" }
    end if
    if pid == 0
        // Child: dup write end of pipe over stdout, close both ends, exec.
        let _o: int = fd.fd_dup2(write_fd, fd.STDOUT())
        let _c1: int = fd.fd_close(read_fd)
        let _c2: int = fd.fd_close(write_fd)
        let _x: int = p.process_run_exec(program, args)
        p.exit_now(127)
    end if

    // Parent: close write end, read until EOF, wait.
    let _cw: int = fd.fd_close(write_fd)
    mut output: string = ""
    let chunk_size: int = 4096
    mut keep_reading: bool = true
    while keep_reading
        let chunk: string = fd.fd_read(read_fd, chunk_size)
        if str.length(chunk) == 0
            keep_reading = false
        else
            output = output + chunk
        end if
    end while
    let _cr: int = fd.fd_close(read_fd)
    let exit: int = p.process_wait(pid)
    return CaptureResult { exit_code: exit, stdout: output }
end process_run_capture

// Spawn `program args` with the given string written to the child's stdin.
// stdout/stderr inherit the parent terminal. Returns exit code.
// On any setup failure (fork, pipe, exec), returns non-zero.
fn process_run_with_stdin(program: string, args: [string], input: string): int
    let pipe_fds: [int] = fd.fd_pipe()
    if pipe_fds.length() != 2
        return -1
    end if
    let read_fd: int = pipe_fds[0]
    let write_fd: int = pipe_fds[1]

    let pid: int = p.process_fork()
    if pid < 0
        let _r: int = fd.fd_close(read_fd)
        let _w: int = fd.fd_close(write_fd)
        return -1
    end if
    if pid == 0
        // Child: dup read end of pipe over stdin, close both ends, exec.
        let _i: int = fd.fd_dup2(read_fd, fd.STDIN())
        let _c1: int = fd.fd_close(read_fd)
        let _c2: int = fd.fd_close(write_fd)
        let _x: int = p.process_run_exec(program, args)
        p.exit_now(127)
    end if

    // Parent: close read end, write input, close write, wait.
    let _cr: int = fd.fd_close(read_fd)
    let _wn: int = fd.fd_write(write_fd, input)
    let _cw: int = fd.fd_close(write_fd)
    return p.process_wait(pid)
end process_run_with_stdin

// Query incus for the container's state. Uses `incus list --project <p>
// --format csv -c s <name>` which outputs just the STATE column ("RUNNING",
// "STOPPED", etc.) for matching containers. Empty output (no match) means
// the container doesn't exist in this project; we return "MISSING".
fn container_state(project: string, name: string): rg.Result[string, string]
    let cap: CaptureResult = process_run_capture("incus", [
        "list", "--project", project, "--format", "csv", "-c", "s", name
    ])
    if cap.exit_code != 0
        return @Result[string, string].Err("incus list exited with code " + convert.to_string(cap.exit_code))
    end if

    // Trim trailing newline + whitespace from stdout.
    let trimmed: string = str.trim_ws(cap.stdout)
    if str.length(trimmed) == 0
        return @Result[string, string].Ok("MISSING")
    end if
    return @Result[string, string].Ok(trimmed)
end container_state

// Get the current process's effective UID as a decimal string. Used by
// `repoman shell` to pass --user to incus exec so the in-container shell
// runs as the host user (matched against claude-share's UID-mapping).
// Reef stdlib doesn't expose getuid() publicly today, so we shell out to
// `id -u` and parse stdout.
fn host_uid(): rg.Result[string, string]
    let cap: CaptureResult = process_run_capture("id", ["-u"])
    if cap.exit_code != 0
        return @Result[string, string].Err("id -u exited with code " + convert.to_string(cap.exit_code))
    end if
    let trimmed: string = str.trim_ws(cap.stdout)
    if str.length(trimmed) == 0
        return @Result[string, string].Err("id -u returned empty output")
    end if
    return @Result[string, string].Ok(trimmed)
end host_uid

fn is_lower_alnum_or_hyphen(c: char): bool
    if c >= 'a' and c <= 'z'
        return true
    end if
    if c >= '0' and c <= '9'
        return true
    end if
    if c == '-'
        return true
    end if
    return false
end is_lower_alnum_or_hyphen

fn validate_name(name: string): bool
    let n: int = str.length(name)
    if n == 0
        return false
    end if
    if n > 63
        return false
    end if
    if name[0] == '-'
        return false
    end if
    mut i: int = 0
    while i < n
        if not is_lower_alnum_or_hyphen(name[i])
            return false
        end if
        i = i + 1
    end while
    return true
end validate_name

// Run `incus <args>`. Returns Ok(true) on exit 0, Err with a brief diagnostic
// on non-zero. Stderr inherits the parent terminal.
fn run_incus(args: [string]): rg.Result[bool, string]
    let pid: int = p.process_run("incus", args)
    if pid < 0
        return @Result[bool, string].Err("failed to spawn 'incus' (is it installed?)")
    end if
    let exit: int = p.process_wait(pid)
    if exit == 0
        return @Result[bool, string].Ok(true)
    end if
    return @Result[bool, string].Err("incus exited with code " + convert.to_string(exit))
end run_incus

fn project_ensure(project: string, verbose: bool): rg.Result[bool, string]
    // `incus project show <name>` exits 0 if it exists, non-0 otherwise.
    // Quiet mode silences the YAML dump on success and the "Error:
    // Project not found" stderr on failure; verbose mode passes through.
    mut pid: int = -1
    if verbose
        pid = p.process_run("incus", ["project", "show", project])
    else
        pid = process_run_silent("incus", ["project", "show", project])
    end if
    let exit: int = p.process_wait(pid)
    if exit == 0
        return @Result[bool, string].Ok(true)
    end if
    // Create with all features disabled so the project is a pure container
    // namespace and shares images/profiles/networks/storage with the default
    // project. Without this, profiles like 'claude-share' that live in the
    // default project would be invisible to containers in this project.
    return run_incus([
        "project", "create", project,
        "-c", "features.images=false",
        "-c", "features.profiles=false",
        "-c", "features.networks=false",
        "-c", "features.storage.volumes=false",
        "-c", "features.storage.buckets=false"
    ])
end project_ensure

fn project_present(project: string): rg.Result[bool, string]
    let pid: int = process_run_silent("incus", ["project", "show", project])
    if pid < 0
        return @Result[bool, string].Err("failed to spawn 'incus project show'")
    end if
    let exit: int = p.process_wait(pid)
    if exit == 0
        return @Result[bool, string].Ok(true)
    end if
    return @Result[bool, string].Ok(false)
end project_present

fn container_exists(project: string, name: string, verbose: bool): rg.Result[bool, string]
    // `incus info --project <p> <name>` exits 0 if it exists.
    // Quiet silences both info dump and error output; verbose passes through.
    mut pid: int = -1
    if verbose
        pid = p.process_run("incus", ["info", "--project", project, name])
    else
        pid = process_run_silent("incus", ["info", "--project", project, name])
    end if
    let exit: int = p.process_wait(pid)
    if exit == 0
        return @Result[bool, string].Ok(true)
    end if
    return @Result[bool, string].Ok(false)
end container_exists

fn launch(project: string, name: string, image: string, profiles: [string]): rg.Result[bool, string]
    let pn: int = profiles.length()
    // argv shape: ["launch", "--project", project, ("--profile" P)*, image, name]
    mut args: [string] = new [string](3 + 2 * pn + 2)
    args[0] = "launch"
    args[1] = "--project"
    args[2] = project
    mut i: int = 0
    while i < pn
        args[3 + i * 2] = "--profile"
        args[3 + i * 2 + 1] = profiles[i]
        i = i + 1
    end while
    args[3 + 2 * pn] = image
    args[3 + 2 * pn + 1] = name
    return run_incus(args)
end launch

fn device_add_disk(project: string, name: string, dev: string, src: string, dst: string): rg.Result[bool, string]
    return run_incus([
        "config", "device", "add",
        "--project", project,
        name,
        dev,
        "disk",
        "source=" + src,
        "path=" + dst
    ])
end device_add_disk

// Like device_add_disk but with extra options like ["shift=true",
// "readonly=true"] appended to the incus argv.
fn device_add_disk_opts(project: string, name: string, dev: string, src: string, dst: string, opts: [string]): rg.Result[bool, string]
    let on: int = opts.length()
    // Final argv: ["config", "device", "add", "--project", P, NAME, DEV, "disk",
    //             "source=...", "path=...", opts...]
    mut args: [string] = new [string](10 + on)
    args[0] = "config"
    args[1] = "device"
    args[2] = "add"
    args[3] = "--project"
    args[4] = project
    args[5] = name
    args[6] = dev
    args[7] = "disk"
    args[8] = "source=" + src
    args[9] = "path=" + dst
    mut i: int = 0
    while i < on
        args[10 + i] = opts[i]
        i = i + 1
    end while
    return run_incus(args)
end device_add_disk_opts

fn set_env_var(project: string, name: string, key: string, val: string): rg.Result[bool, string]
    return run_incus([
        "config", "set",
        "--project", project,
        name,
        "environment." + key + "=" + val
    ])
end set_env_var

fn restart(project: string, name: string): rg.Result[bool, string]
    return run_incus(["restart", "--project", project, name])
end restart

fn delete_container(project: string, name: string): rg.Result[bool, string]
    return run_incus(["delete", "--project", project, "--force", name])
end delete_container

fn delete_profile(project: string, name: string): rg.Result[bool, string]
    return run_incus(["profile", "delete", "--project", project, name])
end delete_profile

// Returns Ok(true) if the named profile exists in the given project,
// Ok(false) otherwise. Errors only on subprocess failure.
fn profile_exists(project: string, name: string): rg.Result[bool, string]
    let pid: int = process_run_silent("incus", [
        "profile", "show", "--project", project, name
    ])
    if pid < 0
        return @Result[bool, string].Err("failed to spawn 'incus profile show'")
    end if
    let exit: int = p.process_wait(pid)
    if exit == 0
        return @Result[bool, string].Ok(true)
    end if
    return @Result[bool, string].Ok(false)
end profile_exists

// Idempotent: ensure the profile exists with the given YAML body.
// Step 1: try `incus profile create` (no-op error if exists).
// Step 2: `incus profile edit` reads stdin and replaces the profile body.
fn profile_create_or_edit(project: string, name: string, yaml: string): rg.Result[bool, string]
    // Step 1: create (silent on failure — profile may already exist)
    let create_pid: int = process_run_silent("incus", [
        "profile", "create", "--project", project, name
    ])
    let _ce: int = p.process_wait(create_pid)

    // Step 2: edit with YAML on stdin
    let edit_exit: int = process_run_with_stdin("incus", [
        "profile", "edit", "--project", project, name
    ], yaml)
    if edit_exit == 0
        return @Result[bool, string].Ok(true)
    end if
    return @Result[bool, string].Err("incus profile edit exited with code " + convert.to_string(edit_exit))
end profile_create_or_edit

// Returns the YAML body of the named profile (the same output as
// `incus profile show <project> <name>`). Errors if the profile doesn't
// exist or the subprocess fails.
fn profile_get(project: string, name: string): rg.Result[string, string]
    let cap: CaptureResult = process_run_capture("incus", [
        "profile", "show", "--project", project, name
    ])
    if cap.exit_code != 0
        return @Result[string, string].Err("incus profile show exited " + convert.to_string(cap.exit_code))
    end if
    return @Result[string, string].Ok(cap.stdout)
end profile_get

end module