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

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

    Project: repoman
   Filename: src/profile.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Profile library: vendor/user shadowing and ${HOST_LAN_IP}/${USER}/${HOME} substitution
     
******************************************************************************/

module profile

import core.str
import core.result_generic as rg
import core.convert as convert
import io.file as iofile
import io.dir as iodir
import sys.env
import paths
import incus

export
    type ProfileEntry
    type HostFacts
    fn vendor_dir(): string
    fn user_dir(home_dir: string): string
    fn render(yaml: string, host: HostFacts): string
    fn lookup(name: string, home_dir: string): rg.Result[string, string]
    fn list_all(home_dir: string): [ProfileEntry]
    fn install(name: string, home_dir: string, host: HostFacts): rg.Result[bool, string]
    fn remove_profile(name: string): rg.Result[bool, string]
    fn show(name: string, home_dir: string, host: HostFacts): rg.Result[string, string]
    fn diff(name: string, home_dir: string, host: HostFacts): rg.Result[string, string]
end export

// One entry from the profile library, populated by list_all.
type ProfileEntry = struct
    name:      string         // e.g., "claude-share"
    source:    string         // "user", "vendor", or "user (shadows vendor)"
    file_path: string         // resolved file path
    installed: bool           // present in incus state
end ProfileEntry

// Substitution context for templated profile YAML.
type HostFacts = struct
    lan_ip: string
    user:   string
    home:   string
end HostFacts

// (function bodies follow in subsequent tasks)

fn vendor_dir(): string
    return "/usr/local/share/repoman/profiles"
end vendor_dir

fn user_dir(home_dir: string): string
    let suffix: string = ".config/repoman/profiles.d"
    if str.is_empty(home_dir)
        return "/" + suffix
    end if
    return paths.join(home_dir, suffix)
end user_dir

fn render(yaml: string, host: HostFacts): string
    let s1: string = str.replace(yaml, "\${HOST_LAN_IP}", host.lan_ip)
    let s2: string = str.replace(s1,   "\${USER}",        host.user)
    let s3: string = str.replace(s2,   "\${HOME}",        host.home)
    return s3
end render

fn lookup(name: string, home_dir: string): rg.Result[string, string]
    let user_path: string = paths.join(user_dir(home_dir), name + ".yml")
    if iofile.fileExists(user_path)
        return @Result[string, string].Ok(user_path)
    end if
    let vendor_path: string = paths.join(vendor_dir(), name + ".yml")
    if iofile.fileExists(vendor_path)
        return @Result[string, string].Ok(vendor_path)
    end if
    return @Result[string, string].Err("profile not found: " + name + " (looked in " + user_path + " and " + vendor_path + ")")
end lookup

fn list_all(home_dir: string): [ProfileEntry]
    // Buffers for filename lists. Cap at 256 per dir; profile libraries
    // are not expected to be enormous.
    let max_files: int = 256
    mut user_buf: [string] = new [string](max_files)
    mut vendor_buf: [string] = new [string](max_files)

    let u_dir: string = user_dir(home_dir)
    mut user_count: int = 0
    if iodir.dir_exists(u_dir)
        user_count = iodir.list_dir(u_dir, user_buf, max_files)
    end if

    let v_dir: string = vendor_dir()
    mut vendor_count: int = 0
    if iodir.dir_exists(v_dir)
        vendor_count = iodir.list_dir(v_dir, vendor_buf, max_files)
    end if

    // Pre-allocate result buffer at worst-case size.
    let cap: int = user_count + vendor_count
    mut entries_buf: [ProfileEntry] = new [ProfileEntry](cap)
    mut e_count: int = 0

    // Pass 1: add all user-dir *.yml files
    mut i: int = 0
    while i < user_count
        let fname: string = user_buf[i]
        if str.ends_with(fname, ".yml")
            let name: string = str.substring(fname, 0, str.length(fname) - 4)
            let path: string = paths.join(u_dir, fname)
            let installed_r = incus.profile_exists("default", name)
            mut installed: bool = false
            if rg.is_ok(installed_r)
                installed = rg.unwrap_ok(installed_r)
            end if
            entries_buf[e_count] = ProfileEntry {
                name:      name,
                source:    "user",
                file_path: path,
                installed: installed
            }
            e_count = e_count + 1
        end if
        i = i + 1
    end while

    // Pass 2: add vendor-dir *.yml files NOT already present (so user wins)
    mut j: int = 0
    while j < vendor_count
        let fname: string = vendor_buf[j]
        if str.ends_with(fname, ".yml")
            let name: string = str.substring(fname, 0, str.length(fname) - 4)
            // Check if name already in entries_buf
            mut shadowed: bool = false
            mut k: int = 0
            while k < e_count
                if entries_buf[k].name == name
                    shadowed = true
                    // Update the existing user entry's source label to indicate shadow
                    entries_buf[k] = ProfileEntry {
                        name:      entries_buf[k].name,
                        source:    "user (shadows vendor)",
                        file_path: entries_buf[k].file_path,
                        installed: entries_buf[k].installed
                    }
                end if
                k = k + 1
            end while
            if not shadowed
                let path: string = paths.join(v_dir, fname)
                let installed_r = incus.profile_exists("default", name)
                mut installed: bool = false
                if rg.is_ok(installed_r)
                    installed = rg.unwrap_ok(installed_r)
                end if
                entries_buf[e_count] = ProfileEntry {
                    name:      name,
                    source:    "vendor",
                    file_path: path,
                    installed: installed
                }
                e_count = e_count + 1
            end if
        end if
        j = j + 1
    end while

    // Compact to actual size
    mut entries: [ProfileEntry] = new [ProfileEntry](e_count)
    mut m: int = 0
    while m < e_count
        entries[m] = entries_buf[m]
        m = m + 1
    end while
    return entries
end list_all

fn install(name: string, home_dir: string, host: HostFacts): rg.Result[bool, string]
    // Resolve the file (user or vendor)
    let path_r = lookup(name, home_dir)
    if rg.is_err(path_r)
        return @Result[bool, string].Err(rg.unwrap_err(path_r))
    end if
    let path: string = rg.unwrap_ok(path_r)

    // Read the file
    let yaml: string = iofile.readFile(path)
    if str.length(yaml) == 0
        return @Result[bool, string].Err("empty or unreadable profile file: " + path)
    end if

    // Render — but if HOST_LAN_IP is needed and host.lan_ip is empty, fail with a hint
    if str.contains(yaml, "\${HOST_LAN_IP}") and str.length(host.lan_ip) == 0
        return @Result[bool, string].Err("profile " + name + " requires \${HOST_LAN_IP} but [host].lan_ip is empty in registry. Run 'repoman setup' to detect and store the host LAN IP.")
    end if
    let rendered: string = render(yaml, host)

    // Apply via incus
    return incus.profile_create_or_edit("default", name, rendered)
end install

fn remove_profile(name: string): rg.Result[bool, string]
    return incus.delete_profile("default", name)
end remove_profile

fn show(name: string, home_dir: string, host: HostFacts): rg.Result[string, string]
    let path_r = lookup(name, home_dir)
    if rg.is_err(path_r)
        return @Result[string, string].Err(rg.unwrap_err(path_r))
    end if
    let path: string = rg.unwrap_ok(path_r)
    let yaml: string = iofile.readFile(path)
    let rendered: string = render(yaml, host)
    return @Result[string, string].Ok(rendered)
end show

fn diff(name: string, home_dir: string, host: HostFacts): rg.Result[string, string]
    // Render the file
    let path_r = lookup(name, home_dir)
    if rg.is_err(path_r)
        return @Result[string, string].Err(rg.unwrap_err(path_r))
    end if
    let path: string = rg.unwrap_ok(path_r)
    let yaml: string = iofile.readFile(path)
    let rendered: string = render(yaml, host)

    // Fetch incus state
    let incus_r = incus.profile_get("default", name)
    if rg.is_err(incus_r)
        // Profile not installed — diff shows the rendered file as "would install"
        let msg: string = "profile " + name + " is not installed. Rendered would-be content:\n\n" + rendered
        return @Result[string, string].Ok(msg)
    end if
    let live: string = rg.unwrap_ok(incus_r)

    if rendered == live
        return @Result[string, string].Ok("(no drift)")
    end if

    // Simple side-by-side: file content marked '-- file --', incus content '-- incus --'.
    let header: string = "--- profile file (rendered): " + path + "\n+++ incus state\n"
    let body: string = "-- file --\n" + rendered + "\n-- incus --\n" + live
    return @Result[string, string].Ok(header + body)
end diff

end module