/**
 * 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 } from 'electron';
import path from 'path';
import { spawn, ChildProcess } from 'child_process';

// ─── 配置 ───

const isDev = process.env.NODE_ENV !== 'production';
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');

// ─── 后端服务器 ───

let serverProcess: ChildProcess | null = null;

function startServer(): Promise<void> {
  return new Promise((resolve, reject) => {
    // 在开发模式下，服务器由 concurrently 启动
    if (isDev && process.env.KB_SERVER_RUNNING === '1') {
      resolve();
      return;
    }

    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: 'production',
      },
      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;
    });

    // 超时兜底
    setTimeout(() => resolve(), 5000);
  });
}

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.js'),
      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;
  });
}

// ─── 应用生命周期 ───

app.whenReady().then(async () => {
  try {
    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();
});