/**
 * HoloLake Desktop · Electron 主进程
 *
 * 职责：
 * 1. 创建应用窗口
 * 2. 启动知识库后端服务器（Express + Git 引擎）
 * 3. 管理应用生命周期
 *
 * 架构：
 *   Electron Main Process
 *   ├── 启动 Express 服务器（Git 引擎层，端口 3890）
 *   ├── 创建 BrowserWindow（加载 Vite 前端或打包后的 dist）
 *   └── 数据存储：~/Library/Application Support/HoloLake Era/data/
 */

import { app, BrowserWindow, shell, dialog, ipcMain, safeStorage } from 'electron';
import path from 'path';
import { spawn, ChildProcess } from 'child_process';
import fs from 'fs';

// ─── 配置 ───

const isDev = !app.isPackaged;
const SERVER_PORT = 3890;
const CLIENT_PORT = 5180;

// 数据目录：macOS 标准位置
const DATA_DIR = path.join(app.getPath('userData'), 'data');
const KB_REPO_PATH = path.join(DATA_DIR, 'knowledge-base');
const MODEL_CONFIG_PATH = path.join(app.getPath('userData'), 'model-config.json');

interface ModelConfigFile {
  baseUrl: string;
  model: string;
  encryptedKey?: string;
}

function readModelConfig(): ModelConfigFile {
  try {
    return JSON.parse(fs.readFileSync(MODEL_CONFIG_PATH, 'utf8')) as ModelConfigFile;
  } catch {
    return { baseUrl: 'https://api.openai.com/v1', model: 'gpt-4o' };
  }
}

function applyModelConfig(): ModelConfigFile {
  const config = readModelConfig();
  process.env.HOLOLAKE_LLM_BASE = config.baseUrl;
  process.env.HOLOLAKE_LLM_MODEL = config.model;
  if (config.encryptedKey && safeStorage.isEncryptionAvailable()) {
    process.env.HOLOLAKE_LLM_KEY = safeStorage.decryptString(Buffer.from(config.encryptedKey, 'base64'));
  }
  return config;
}

// ─── 后端服务器 ───

let serverProcess: ChildProcess | null = null;

function startServer(): Promise<void> {
  return new Promise((resolve, reject) => {
    if (isDev) {
      // 开发模式：用 spawn 启动外部 tsx
      const serverScript = path.resolve(__dirname, '../../guanghu-knowledge-base/server/index.ts');
      serverProcess = spawn('npx', ['tsx', serverScript], {
        env: {
          ...process.env,
          KB_PORT: String(SERVER_PORT),
          KB_REPO_PATH,
          NODE_ENV: 'development',
        },
        cwd: path.resolve(__dirname, '../..'),
        stdio: ['pipe', 'pipe', 'pipe'],
      });

      serverProcess.stdout?.on('data', (data: Buffer) => {
        const msg = data.toString().trim();
        console.log(`[KB Server] ${msg}`);
        if (msg.includes('已启动')) resolve();
      });

      serverProcess.stderr?.on('data', (data: Buffer) => {
        console.error(`[KB Server Error] ${data.toString().trim()}`);
      });

      serverProcess.on('error', (err: Error) => {
        console.error('服务器启动失败:', err);
        reject(err);
      });

      serverProcess.on('exit', (code: number | null) => {
        console.log(`[KB Server] 退出，code=${code}`);
        serverProcess = null;
      });

      setTimeout(() => resolve(), 5000);
    } else {
      // 生产模式：直接在主进程内加载 server-bundle
      try {
        process.env.KB_PORT = String(SERVER_PORT);
        process.env.KB_REPO_PATH = KB_REPO_PATH;
        const serverBundle = path.join(__dirname, 'server-bundle.cjs');
        require(serverBundle);
        console.log(`[KB Server] 内嵌启动，端口 ${SERVER_PORT}`);
        resolve();
      } catch (err) {
        console.error('服务器内嵌启动失败:', err);
        reject(err);
      }
    }
  });
}

function stopServer(): void {
  if (serverProcess) {
    serverProcess.kill('SIGTERM');
    serverProcess = null;
  }
}

// ─── 窗口 ───

let mainWindow: BrowserWindow | null = null;

function createWindow(): void {
  mainWindow = new BrowserWindow({
    width: 1280,
    height: 860,
    minWidth: 800,
    minHeight: 600,
    titleBarStyle: 'hiddenInset',
    trafficLightPosition: { x: 16, y: 16 },
    backgroundColor: '#0d1117',
    webPreferences: {
      preload: path.join(__dirname, 'preload.cjs'),
      contextIsolation: true,
      nodeIntegration: false,
    },
  });

  if (isDev) {
    mainWindow.loadURL(`http://localhost:${CLIENT_PORT}`);
    mainWindow.webContents.openDevTools({ mode: 'detach' });
  } else {
    mainWindow.loadFile(path.join(__dirname, '../dist/index.html'));
  }

  // 外部链接用系统浏览器打开
  mainWindow.webContents.setWindowOpenHandler(({ url }) => {
    if (url.startsWith('http')) shell.openExternal(url);
    return { action: 'deny' };
  });

  mainWindow.on('closed', () => {
    mainWindow = null;
  });
}

ipcMain.handle('get-data-path', () => DATA_DIR);
ipcMain.handle('agent:get-config', () => {
  const config = readModelConfig();
  return {
    baseUrl: config.baseUrl,
    model: config.model,
    configured: Boolean(config.encryptedKey && safeStorage.isEncryptionAvailable()),
  };
});
ipcMain.handle('agent:save-config', (_event, input: { baseUrl: string; model: string; apiKey?: string }) => {
  const baseUrl = String(input.baseUrl || '').trim().replace(/\/$/, '');
  const model = String(input.model || '').trim();
  if (!/^https:\/\//i.test(baseUrl)) throw new Error('模型服务地址必须使用 HTTPS');
  if (!model) throw new Error('模型名称不能为空');
  if (!safeStorage.isEncryptionAvailable()) throw new Error('macOS 加密存储当前不可用');
  const previous = readModelConfig();
  const encryptedKey = input.apiKey
    ? safeStorage.encryptString(String(input.apiKey)).toString('base64')
    : previous.encryptedKey;
  if (!encryptedKey) throw new Error('请填写模型密钥');
  fs.mkdirSync(path.dirname(MODEL_CONFIG_PATH), { recursive: true });
  fs.writeFileSync(MODEL_CONFIG_PATH, JSON.stringify({ baseUrl, model, encryptedKey }), { mode: 0o600 });
  applyModelConfig();
  return { baseUrl, model, configured: true };
});

// ─── 应用生命周期 ───

app.whenReady().then(async () => {
  try {
    applyModelConfig();
    await startServer();
    createWindow();
  } catch (err) {
    dialog.showErrorBox('启动失败', `知识库引擎启动失败：${err}`);
    app.quit();
  }

  app.on('activate', () => {
    if (BrowserWindow.getAllWindows().length === 0) createWindow();
  });
});

app.on('window-all-closed', () => {
  stopServer();
  if (process.platform !== 'darwin') app.quit();
});

app.on('before-quit', () => {
  stopServer();
});