'use strict';
// Bot 註冊表：web 控制台管理的 bot 實例清單。
// bot 設定放在 ~/.tgcodex/bots/<name>/tgcodex.config.json。
// pm2 上帶 TGCODEX_CONFIG 但不在註冊表裡的 bot 程序會被自動探索回來
//（registry.json 遺失時的自我修復）。
const fs = require('fs');
const path = require('path');
const { TGCODEX_HOME, jlist } = require('./pm2util');
const { loadConfig, SANDBOX_MODES } = require('./config');

const REG_FILE = path.join(TGCODEX_HOME, 'registry.json');
const BOTS_DIR = path.join(TGCODEX_HOME, 'bots');
const BOT_SCRIPT = path.join(__dirname, 'index.js');

const NAME_RE = /^[A-Za-z0-9][A-Za-z0-9._-]{0,39}$/;

function loadRegistry() {
  try {
    const data = JSON.parse(fs.readFileSync(REG_FILE, 'utf-8'));
    return { bots: data.bots || {} };
  } catch {
    return { bots: {} };
  }
}

function saveRegistry(reg) {
  fs.mkdirSync(TGCODEX_HOME, { recursive: true });
  fs.writeFileSync(REG_FILE, JSON.stringify(reg, null, 2) + '\n');
}

function maskToken(token) {
  if (!token) return '';
  return token.length <= 10 ? '***' : token.slice(0, 6) + '…' + token.slice(-4);
}

// 從 pm2 探索不在註冊表裡的 bot（跑著我們 src/index.js 且帶 TGCODEX_CONFIG 的程序）
function discoverFromPm2(reg, list) {
  let changed = false;
  for (const p of list) {
    // pm2 版本不同，自訂 env 可能在 pm2_env.env 或直接攤平在 pm2_env 上
    const env = { ...(p.pm2_env || {}), ...(p.pm2_env?.env || {}) };
    const script = p.pm2_env?.pm_exec_path || '';
    if (!env.TGCODEX_CONFIG || typeof env.TGCODEX_CONFIG !== 'string') continue;
    if (path.resolve(script) !== path.resolve(BOT_SCRIPT)) continue;
    if (reg.bots[p.name]) continue;
    if (!fs.existsSync(env.TGCODEX_CONFIG)) continue;
    reg.bots[p.name] = { configPath: env.TGCODEX_CONFIG, source: 'external' };
    changed = true;
  }
  if (changed) saveRegistry(reg);
}

async function listBots() {
  const reg = loadRegistry();
  let list = [];
  try {
    list = await jlist();
  } catch { /* pm2 不在也要能列出設定 */ }
  discoverFromPm2(reg, list);

  const bots = [];
  for (const [name, entry] of Object.entries(reg.bots)) {
    let cfg = null;
    let error = null;
    try {
      cfg = loadConfig(entry.configPath);
    } catch (err) {
      error = err.message;
    }
    if (!fs.existsSync(entry.configPath)) error = '設定檔已不存在';
    const proc = cfg ? list.find((p) => p.name === cfg.pm2Name) : list.find((p) => p.name === name);
    bots.push({
      name,
      source: entry.source || 'ui',
      configPath: entry.configPath,
      error,
      workDir: cfg?.workDir || null,
      sandbox: cfg?.sandbox || null,
      model: cfg?.model || '',
      reasoningEffort: cfg?.reasoningEffort || '',
      serviceTier: cfg?.serviceTier || '',
      timeoutMinutes: cfg?.timeoutMinutes || null,
      tokenMasked: maskToken(cfg?.telegramToken),
      hasToken: !!cfg?.telegramToken,
      pm2Name: cfg?.pm2Name || name,
      pmId: proc?.pm_id ?? null,
      status: proc?.pm2_env?.status || 'not_started',
      pid: proc?.pid || null,
      memory: proc?.monit?.memory ?? 0,
      cpu: proc?.monit?.cpu ?? '-',
      restarts: proc?.pm2_env?.restart_time ?? 0,
      uptime: proc?.pm2_env?.pm_uptime ?? null,
    });
  }
  bots.sort((a, b) => a.name.localeCompare(b.name));
  return bots;
}

function validateBotInput({ name, token, workDir, sandbox }, { isCreate }) {
  if (isCreate) {
    if (!name || !NAME_RE.test(name)) {
      throw new Error('名稱只能是英數字開頭，含英數字、點、底線、連字號，最長 40 字');
    }
    if (!token) throw new Error('token 不能是空的');
  }
  if (workDir !== undefined) {
    if (!workDir || !fs.existsSync(workDir)) throw new Error(`工作目錄不存在：${workDir}`);
    if (!fs.statSync(workDir).isDirectory()) throw new Error(`工作目錄不是資料夾：${workDir}`);
  }
  if (sandbox !== undefined && !SANDBOX_MODES.includes(sandbox)) {
    throw new Error(`sandbox 必須是 ${SANDBOX_MODES.join(' / ')}`);
  }
}

async function createBot({ name, token, workDir, sandbox, model, reasoningEffort, serviceTier, timeoutMinutes }) {
  validateBotInput({ name, token, workDir, sandbox }, { isCreate: true });
  const reg = loadRegistry();
  if (reg.bots[name]) throw new Error(`已有同名 bot：${name}`);
  const list = await jlist().catch(() => []);
  if (list.some((p) => p.name === name)) throw new Error(`pm2 上已有同名程序：${name}`);

  const dir = path.join(BOTS_DIR, name);
  fs.mkdirSync(dir, { recursive: true });
  const configPath = path.join(dir, 'tgcodex.config.json');
  const config = {
    telegramToken: token,
    workDir: path.resolve(workDir),
    sandbox: sandbox || 'workspace-write',
    model: model || '',
    reasoningEffort: reasoningEffort || '',
    serviceTier: serviceTier || '',
    timeoutMinutes: Number(timeoutMinutes) || 30,
    pm2Name: name,
    // UI 建的 bot 不各自開 web，統一由控制台管理
    web: { enabled: false, port: 3799, host: '127.0.0.1' },
  };
  fs.writeFileSync(configPath, JSON.stringify(config, null, 2) + '\n');

  reg.bots[name] = { configPath, source: 'ui', createdAt: new Date().toISOString() };
  saveRegistry(reg);
  return loadConfig(configPath);
}

async function updateBot(name, patch) {
  const reg = loadRegistry();
  const entry = reg.bots[name];
  if (!entry) throw new Error(`找不到 bot：${name}`);
  const raw = JSON.parse(fs.readFileSync(entry.configPath, 'utf-8'));

  if (patch.workDir !== undefined && patch.workDir !== '') {
    validateBotInput({ workDir: patch.workDir }, { isCreate: false });
    raw.workDir = path.resolve(patch.workDir);
  }
  if (patch.token) raw.telegramToken = patch.token; // 空字串 = 不變更
  if (patch.sandbox !== undefined) {
    validateBotInput({ sandbox: patch.sandbox }, { isCreate: false });
    raw.sandbox = patch.sandbox;
  }
  if (patch.model !== undefined) raw.model = patch.model;
  if (patch.reasoningEffort !== undefined) raw.reasoningEffort = patch.reasoningEffort;
  if (patch.serviceTier !== undefined) raw.serviceTier = patch.serviceTier;
  if (patch.timeoutMinutes !== undefined && Number(patch.timeoutMinutes) > 0) {
    raw.timeoutMinutes = Number(patch.timeoutMinutes);
  }

  fs.writeFileSync(entry.configPath, JSON.stringify(raw, null, 2) + '\n');
  return loadConfig(entry.configPath);
}

function getBotConfig(name) {
  const reg = loadRegistry();
  const entry = reg.bots[name];
  if (!entry) throw new Error(`找不到 bot：${name}`);
  return loadConfig(entry.configPath);
}

function removeBot(name, { deleteFiles = false } = {}) {
  const reg = loadRegistry();
  const entry = reg.bots[name];
  if (!entry) throw new Error(`找不到 bot：${name}`);
  delete reg.bots[name];
  saveRegistry(reg);
  if (deleteFiles) {
    // 只允許刪除放在 ~/.tgcodex/bots/ 底下的（UI 建的）；folder 模式的設定檔不動
    const dir = path.dirname(entry.configPath);
    if (dir.startsWith(BOTS_DIR + path.sep)) {
      fs.rmSync(dir, { recursive: true, force: true });
    }
  }
  return entry;
}

module.exports = { listBots, createBot, updateBot, removeBot, getBotConfig, maskToken, BOTS_DIR };