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

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

    Project: repoman
   Filename: src/config.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Registry parse/serialize/migrate (schema 1 -> 2 -> 3) and per-project overrides
     
******************************************************************************/

module config

import core.str
import core.result_generic as rg
import encoding.toml as toml
import io.file as iofile
import io.dir as iodir
import io.path as iopath
import paths

export
    type Defaults
    type Host
    type Project
    type Override
    type Mount
    type Registry
    type EffectiveConfig
    fn parse_registry(toml_text: string): rg.Result[Registry, string]
    fn serialize_registry(reg: Registry): string
    fn parse_override(toml_text: string): rg.Result[Override, string]
    fn merge_with_defaults(name: string, repo: string, image_flag: string, ov: Override, d: Defaults): EffectiveConfig
    fn with_projects(reg: Registry, new_projects: [Project]): Registry
    fn add_project(reg: Registry, p: Project): rg.Result[Registry, string]
    fn update_last_sync(reg: Registry, name: string, ts: string): rg.Result[Registry, string]
    fn remove_project(reg: Registry, name: string): rg.Result[Registry, string]
    fn registry_path(home_dir: string): string
    fn default_registry(home_dir: string): Registry
    fn load_or_init(home_dir: string): rg.Result[Registry, string]
    fn save(reg: Registry, cfg_path: string): rg.Result[bool, string]
end export

type Host = struct
    lan_ip: string
end Host

type Defaults = struct
    repos_root: string
    backup_root: string
    logdir: string
    incus_project: string
    default_image: string
    profiles: [string]
end Defaults

type Project = struct
    name: string
    repo: string
    image: string
    profiles: [string]
    created: string
    last_sync: string
    backup: bool
end Project

type Mount = struct
    source: string
    path: string
end Mount

type Override = struct
    image: string
    profiles: [string]
    has_profiles: bool
    mounts: [Mount]
    env_keys: [string]
    env_values: [string]
end Override

type Registry = struct
    schema: int
    host: Host
    output: string
    defaults: Defaults
    projects: [Project]
end Registry

type EffectiveConfig = struct
    name: string
    repo: string
    repo_path: string
    image: string
    profiles: [string]
    mounts: [Mount]
    env_keys: [string]
    env_values: [string]
end EffectiveConfig

// Extract the host portion of an `http://<host>:<port>` URL string.
// Returns "" if the input doesn't match that shape.
fn extract_lan_ip_from_url(url: string): string
    let n: int = str.length(url)
    if n == 0
        return ""
    end if
    let prefix: string = "http://"
    let prefix_len: int = 7
    if not str.starts_with(url, prefix)
        return ""
    end if
    // Find ':' after the prefix
    mut i: int = prefix_len
    while i < n and url[i] != ':'
        i = i + 1
    end while
    if i <= prefix_len
        return ""
    end if
    return str.substring(url, prefix_len, i - prefix_len)
end extract_lan_ip_from_url

// Parse a comma-separated TOML inline array of strings: `["a", "b"]`.
// Tolerates whitespace and missing brackets; returns empty if input is empty.
fn parse_string_array(raw: string): [string]
    let n: int = str.length(raw)
    if n == 0
        return new [string](0)
    end if
    // Strip leading [ and trailing ]
    mut start: int = 0
    mut end_idx: int = n
    if n > 0 and raw[0] == '['
        start = 1
    end if
    if end_idx > start and raw[end_idx - 1] == ']'
        end_idx = end_idx - 1
    end if
    let inner: string = str.substring(raw, start, end_idx - start)

    // Split on commas, then trim quotes and whitespace from each element.
    let inner_len: int = str.length(inner)
    if inner_len == 0
        return new [string](0)
    end if

    // Reef doesn't have a dynamic split-and-collect; use str.split with a max.
    mut parts: [string] = new [string](64)
    let count: int = str.split(inner, ',', parts, 64)

    mut result: [string] = new [string](count)
    mut i: int = 0
    while i < count
        let p: string = str.trim_ws(parts[i])
        // Strip surrounding double quotes if present
        let pl: int = str.length(p)
        if pl >= 2 and p[0] == '"' and p[pl - 1] == '"'
            result[i] = str.substring(p, 1, pl - 2)
        else
            result[i] = p
        end if
        i = i + 1
    end while
    return result
end parse_string_array

fn parse_registry(toml_text: string): rg.Result[Registry, string]
    let doc: toml.TomlDoc = toml.toml_parse_doc(toml_text)
    if doc.truncated
        return @Result[Registry, string].Err("registry too large (>1024 entries)")
    end if

    let schema: int = toml.toml_get_int_doc(doc, "repoman.schema")
    if schema != 1 and schema != 2 and schema != 3
        return @Result[Registry, string].Err("unsupported schema (expected 1, 2, or 3)")
    end if

    // [repoman].output: "quiet" (default) | "verbose"
    mut output: string = toml.toml_get_doc(doc, "repoman.output")
    if str.length(output) == 0
        output = "quiet"
    end if
    if output != "quiet" and output != "verbose"
        return @Result[Registry, string].Err("invalid [repoman].output: " + output + " (expected 'quiet' or 'verbose')")
    end if

    // [defaults].logdir: ~/.local/state/repoman by default
    mut logdir: string = toml.toml_get_doc(doc, "defaults.logdir")
    if str.length(logdir) == 0
        logdir = "~/.local/state/repoman"
    end if

    let defaults: Defaults = Defaults {
        repos_root:    toml.toml_get_doc(doc, "defaults.repos_root"),
        backup_root:   toml.toml_get_doc(doc, "defaults.backup_root"),
        logdir:        logdir,
        incus_project: toml.toml_get_doc(doc, "defaults.incus_project"),
        default_image: toml.toml_get_doc(doc, "defaults.default_image"),
        profiles:      parse_string_array(toml.toml_get_doc(doc, "defaults.profiles"))
    }

    let project_count: int = toml.toml_array_count(doc.keys, doc.count, "project")
    mut projects: [Project] = new [Project](project_count)
    mut i: int = 0
    while i < project_count
        let p: Project = Project {
            name:      toml.toml_array_get(doc.keys, doc.values, doc.count, "project", i, "name"),
            repo:      toml.toml_array_get(doc.keys, doc.values, doc.count, "project", i, "repo"),
            image:     toml.toml_array_get(doc.keys, doc.values, doc.count, "project", i, "image"),
            profiles:  parse_string_array(toml.toml_array_get(doc.keys, doc.values, doc.count, "project", i, "profiles")),
            created:   toml.toml_array_get(doc.keys, doc.values, doc.count, "project", i, "created"),
            last_sync: toml.toml_array_get(doc.keys, doc.values, doc.count, "project", i, "last_sync"),
            backup:    toml.toml_array_get(doc.keys, doc.values, doc.count, "project", i, "backup") != "false"
        }
        projects[i] = p
        i = i + 1
    end while

    // [host].lan_ip — schema 3 reads it directly; schema 2 migration extracts from
    // the now-removed [defaults.llm.ollama_url]; schema 1 has no such value (empty).
    mut lan_ip: string = toml.toml_get_doc(doc, "host.lan_ip")
    if str.length(lan_ip) == 0
        // Fall back: schema 2 migration via [defaults.llm.ollama_url]
        let old_url: string = toml.toml_get_doc(doc, "defaults.llm.ollama_url")
        if str.length(old_url) > 0
            lan_ip = extract_lan_ip_from_url(old_url)
        end if
    end if

    let host: Host = Host {
        lan_ip: lan_ip
    }
    let reg: Registry = Registry {
        schema:   3,
        host:     host,
        output:   output,
        defaults: defaults,
        projects: projects
    }
    return @Result[Registry, string].Ok(reg)
end parse_registry

fn serialize_registry(reg: Registry): string
    let b: toml.TomlBuilder = toml.toml_builder()

    toml.toml_begin_table(b, "repoman")
    toml.toml_set_int(b, "schema", reg.schema)
    toml.toml_set_string(b, "output", reg.output)

    toml.toml_begin_table(b, "host")
    toml.toml_set_string(b, "lan_ip", reg.host.lan_ip)

    toml.toml_begin_table(b, "defaults")
    toml.toml_set_string(b, "repos_root", reg.defaults.repos_root)
    toml.toml_set_string(b, "backup_root", reg.defaults.backup_root)
    toml.toml_set_string(b, "logdir", reg.defaults.logdir)
    toml.toml_set_string(b, "incus_project", reg.defaults.incus_project)
    toml.toml_set_string(b, "default_image", reg.defaults.default_image)
    toml.toml_set_string_array(b, "profiles", reg.defaults.profiles)

    let pn: int = reg.projects.length()
    mut i: int = 0
    while i < pn
        let p: Project = reg.projects[i]
        toml.toml_array_append_table(b, "project")
        toml.toml_set_string(b, "name", p.name)
        toml.toml_set_string(b, "repo", p.repo)
        toml.toml_set_string(b, "image", p.image)
        toml.toml_set_string_array(b, "profiles", p.profiles)
        toml.toml_set_string(b, "created", p.created)
        toml.toml_set_string(b, "last_sync", p.last_sync)
        toml.toml_set_bool(b, "backup", p.backup)
        i = i + 1
    end while

    return toml.toml_render(b)
end serialize_registry

fn parse_override(toml_text: string): rg.Result[Override, string]
    let doc: toml.TomlDoc = toml.toml_parse_doc(toml_text)
    if doc.truncated
        return @Result[Override, string].Err("override too large")
    end if

    let image: string = toml.toml_get_doc(doc, "container.image")
    let profiles_raw: string = toml.toml_get_doc(doc, "container.profiles")
    let has_profiles: bool = toml.toml_has_key_doc(doc, "container.profiles")
    let profiles: [string] = parse_string_array(profiles_raw)

    let mount_count: int = toml.toml_array_count(doc.keys, doc.count, "mount")
    mut mounts: [Mount] = new [Mount](mount_count)
    mut i: int = 0
    while i < mount_count
        mounts[i] = Mount {
            source: toml.toml_array_get(doc.keys, doc.values, doc.count, "mount", i, "source"),
            path:   toml.toml_array_get(doc.keys, doc.values, doc.count, "mount", i, "path")
        }
        i = i + 1
    end while

    // Walk doc.keys for entries starting with "env."
    mut env_keys_buf: [string] = new [string](128)
    mut env_vals_buf: [string] = new [string](128)
    mut env_count: int = 0
    mut k: int = 0
    while k < doc.count
        let key: string = doc.keys[k]
        if str.starts_with(key, "env.")
            if env_count < 128
                env_keys_buf[env_count] = str.substring(key, 4, str.length(key) - 4)
                env_vals_buf[env_count] = doc.values[k]
                env_count = env_count + 1
            end if
        end if
        k = k + 1
    end while

    mut env_keys: [string] = new [string](env_count)
    mut env_vals: [string] = new [string](env_count)
    mut j: int = 0
    while j < env_count
        env_keys[j] = env_keys_buf[j]
        env_vals[j] = env_vals_buf[j]
        j = j + 1
    end while

    let ov: Override = Override {
        image:        image,
        profiles:     profiles,
        has_profiles: has_profiles,
        mounts:       mounts,
        env_keys:     env_keys,
        env_values:   env_vals
    }
    return @Result[Override, string].Ok(ov)
end parse_override

fn merge_with_defaults(name: string, repo: string, image_flag: string, ov: Override, d: Defaults): EffectiveConfig
    let repos_root_expanded: string = paths.expand_home(d.repos_root)
    let repo_path: string = paths.join(repos_root_expanded, repo)

    // Image priority: flag → override → defaults
    mut image: string = d.default_image
    if str.length(ov.image) > 0
        image = ov.image
    end if
    if str.length(image_flag) > 0
        image = image_flag
    end if

    // Profiles: override replaces defaults when has_profiles, else defaults
    mut profiles: [string] = d.profiles
    if ov.has_profiles
        profiles = ov.profiles
    end if

    // Mounts: [auto repo bind] ++ override.mounts
    let ov_mount_count: int = ov.mounts.length()
    mut mounts: [Mount] = new [Mount](1 + ov_mount_count)
    mounts[0] = Mount { source: repo_path, path: repo_path }
    mut i: int = 0
    while i < ov_mount_count
        // Expand ~ in mount source for host paths
        let m: Mount = ov.mounts[i]
        mounts[i + 1] = Mount {
            source: paths.expand_home(m.source),
            path:   m.path
        }
        i = i + 1
    end while

    return EffectiveConfig {
        name:       name,
        repo:       repo,
        repo_path:  repo_path,
        image:      image,
        profiles:   profiles,
        mounts:     mounts,
        env_keys:   ov.env_keys,
        env_values: ov.env_values
    }
end merge_with_defaults

fn add_project(reg: Registry, p: Project): rg.Result[Registry, string]
    let n: int = reg.projects.length()
    mut i: int = 0
    while i < n
        if reg.projects[i].name == p.name
            return @Result[Registry, string].Err("project already exists: " + p.name)
        end if
        i = i + 1
    end while

    mut new_projects: [Project] = new [Project](n + 1)
    mut k: int = 0
    while k < n
        new_projects[k] = reg.projects[k]
        k = k + 1
    end while
    new_projects[n] = p

    return @Result[Registry, string].Ok(with_projects(reg, new_projects))
end add_project

fn update_last_sync(reg: Registry, name: string, ts: string): rg.Result[Registry, string]
    let n: int = reg.projects.length()
    mut found: int = -1
    mut i: int = 0
    while i < n
        if reg.projects[i].name == name
            found = i
        end if
        i = i + 1
    end while

    if found < 0
        return @Result[Registry, string].Err("project not in registry: " + name)
    end if

    mut new_projects: [Project] = new [Project](n)
    mut k: int = 0
    while k < n
        if k == found
            let old: Project = reg.projects[k]
            new_projects[k] = Project {
                name: old.name, repo: old.repo, image: old.image,
                profiles: old.profiles, created: old.created,
                last_sync: ts, backup: old.backup
            }
        else
            new_projects[k] = reg.projects[k]
        end if
        k = k + 1
    end while

    return @Result[Registry, string].Ok(with_projects(reg, new_projects))
end update_last_sync

// Build a new Registry from an existing one plus a replacement projects list.
// Single source of truth for "preserve all top-level Registry fields when
// rewriting projects" — keeps fields from drifting silently across the
// add/update/remove call sites.
fn with_projects(reg: Registry, new_projects: [Project]): Registry
    return Registry {
        schema:   reg.schema,
        host:     reg.host,
        output:   reg.output,
        defaults: reg.defaults,
        projects: new_projects
    }
end with_projects

fn remove_project(reg: Registry, name: string): rg.Result[Registry, string]
    let n: int = reg.projects.length()
    mut found: int = -1
    mut i: int = 0
    while i < n
        if reg.projects[i].name == name
            found = i
        end if
        i = i + 1
    end while

    if found < 0
        return @Result[Registry, string].Err("project not in registry: " + name)
    end if

    mut new_projects: [Project] = new [Project](n - 1)
    mut k: int = 0
    mut j: int = 0
    while k < n
        if k != found
            new_projects[j] = reg.projects[k]
            j = j + 1
        end if
        k = k + 1
    end while

    return @Result[Registry, string].Ok(with_projects(reg, new_projects))
end remove_project

fn registry_path(home_dir: string): string
    let cfg_dir: string = paths.join(home_dir, ".config/repoman")
    return paths.join(cfg_dir, "repoman.toml")
end registry_path

fn default_registry(home_dir: string): Registry
    let repos_root: string = paths.join(home_dir, "repos")
    let logdir: string = paths.join(home_dir, ".local/state/repoman")
    return Registry {
        schema: 3,
        host: Host { lan_ip: "" },
        output: "quiet",
        defaults: Defaults {
            repos_root:    repos_root,
            backup_root:   "/nfs/repos",
            logdir:        logdir,
            incus_project: "repoman",
            default_image: "images:ubuntu/26.04/cloud",
            profiles:      ["default", "claude-share"]
        },
        projects: new [Project](0)
    }
end default_registry

fn load_or_init(home_dir: string): rg.Result[Registry, string]
    let cfg_path: string = registry_path(home_dir)
    let cfg_dir: string = iopath.dirname(cfg_path)

    // Ensure ~/.config/repoman/ exists
    if not iodir.dir_exists(cfg_dir)
        if not iodir.create_dir_all(cfg_dir)
            return @Result[Registry, string].Err("cannot create config dir: " + cfg_dir)
        end if
    end if

    if iofile.fileExists(cfg_path)
        let contents: string = iofile.readFile(cfg_path)
        return parse_registry(contents)
    end if

    // Init: write default registry.
    let reg: Registry = default_registry(home_dir)
    let saved_r = save(reg, cfg_path)
    if rg.is_err(saved_r)
        return @Result[Registry, string].Err(rg.unwrap_err(saved_r))
    end if
    return @Result[Registry, string].Ok(reg)
end load_or_init

// Atomic write: writeFile(.tmp) → fsync(.tmp) → rename(.tmp, target).
// If any step fails, returns Err naming the failing step.
fn save(reg: Registry, cfg_path: string): rg.Result[bool, string]
    let serialized: string = serialize_registry(reg)
    let tmp_path: string = cfg_path + ".tmp"

    if not iofile.writeFile(tmp_path, serialized)
        return @Result[bool, string].Err("write failed: " + tmp_path)
    end if

    if not iofile.fsync(tmp_path)
        // Best effort: clean up tmp
        let _d: bool = iofile.deleteFile(tmp_path)
        return @Result[bool, string].Err("fsync failed: " + tmp_path)
    end if

    if not iofile.rename(tmp_path, cfg_path)
        let _d: bool = iofile.deleteFile(tmp_path)
        return @Result[bool, string].Err("rename failed: " + tmp_path + " → " + cfg_path)
    end if

    return @Result[bool, string].Ok(true)
end save

end module