// main.js — Electron 主进程
// 功能：启动 FastAPI 后端 → 等待就绪 → 加载 Web UI → 管理生命周期

const { app, BrowserWindow, dialog } = require('electron');
const { spawn } = require('child_process');
const path = require('path');
const http = require('http');
const fs = require('fs');

// ---------- 路径配置 ----------
const AGENT_DIR = path.join(__dirname, '..');                     // Agent/ 目录
const VENV_PYTHON = path.join(AGENT_DIR, 'myenv', 'Scripts', 'python.exe');
const HOST = '127.0.0.1';
const PORT = 8765;
const BASE_URL = `http://${HOST}:${PORT}`;

// ---------- 全局状态 ----------
let mainWindow = null;
let pythonProcess = null;

// ---------- FastAPI 生命周期 ----------
function startFastAPI() {
  return new Promise((resolve, reject) => {
    // 如果找不到虚拟环境 Python，尝试使用系统 Python
    let pythonExe = VENV_PYTHON;
    if (!fs.existsSync(pythonExe)) {
      pythonExe = 'python';  // 回退到 PATH 中的 Python
      console.log('[Electron] 未找到 venv Python，使用系统 Python');
    }
    console.log(`[Electron] Python: ${pythonExe}`);
    console.log(`[Electron] Agent 目录: ${AGENT_DIR}`);

    pythonProcess = spawn(pythonExe, [
      '-m', 'uvicorn',
      'web.server:app',
      '--host', HOST,
      '--port', String(PORT),
      '--log-level', 'warning',
    ], {
      cwd: AGENT_DIR,
      env: {
        ...process.env,
        PYTHONPATH: 'src',
        PYTHONUNBUFFERED: '1',
      },
      shell: true,  // Windows 需要 shell 以正确解析路径
      stdio: ['ignore', 'pipe', 'pipe'],
    });

    pythonProcess.stdout.on('data', (data) => {
      console.log(`[FastAPI] ${data.toString().trim()}`);
    });

    pythonProcess.stderr.on('data', (data) => {
      console.log(`[FastAPI] ${data.toString().trim()}`);
    });

    pythonProcess.on('error', (err) => {
      console.error('[Electron] 启动 FastAPI 失败:', err.message);
      reject(err);
    });

    pythonProcess.on('exit', (code) => {
      console.log(`[Electron] FastAPI 进程退出，退出码: ${code}`);
      pythonProcess = null;
      // 非正常退出时提醒用户
      if (code !== 0 && code !== null && mainWindow) {
        dialog.showErrorBox(
          '后端服务异常',
          `FastAPI 服务意外退出（退出码: ${code}）。\n请检查终端输出了解详情。`
        );
      }
    });

    // 轮询等待服务就绪
    waitForReady(resolve, reject, 30);  // 最多等 30 秒
  });
}

function waitForReady(resolve, reject, retriesLeft) {
  if (retriesLeft <= 0) {
    reject(new Error('FastAPI 启动超时，请检查依赖是否安装完整'));
    return;
  }

  const req = http.get(`${BASE_URL}/api/health`, (res) => {
    if (res.statusCode === 200) {
      console.log('[Electron] FastAPI 服务就绪');
      resolve();
    } else {
      retry();
    }
  });

  req.on('error', () => retry());
  req.setTimeout(2000, () => { req.destroy(); retry(); });

  function retry() {
    setTimeout(() => waitForReady(resolve, reject, retriesLeft - 1), 1000);
  }
}

function stopFastAPI() {
  if (pythonProcess) {
    console.log('[Electron] 正在关闭 FastAPI...');
    // Windows 上 kill 整个进程树
    if (process.platform === 'win32') {
      spawn('taskkill', ['/pid', String(pythonProcess.pid), '/f', '/t']);
    } else {
      pythonProcess.kill('SIGTERM');
    }
    pythonProcess = null;
  }
}

// ---------- 窗口管理 ----------
function createWindow() {
  mainWindow = new BrowserWindow({
    width: 1200,
    height: 800,
    minWidth: 800,
    minHeight: 600,
    title: 'minor Agent',
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false,
    },
    show: false,  // 等 ready-to-show 再显示，避免白屏
  });

  mainWindow.loadURL(BASE_URL);

  mainWindow.once('ready-to-show', () => {
    mainWindow.show();
  });

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

  // 在默认浏览器打开外部链接
  mainWindow.webContents.setWindowOpenHandler(({ url }) => {
    require('electron').shell.openExternal(url);
    return { action: 'deny' };
  });
}

// ---------- 应用生命周期 ----------
app.whenReady().then(async () => {
  try {
    await startFastAPI();
    createWindow();
  } catch (err) {
    dialog.showErrorBox(
      '启动失败',
      `无法启动 minor Agent:\n${err.message}\n\n` +
      '请确保已安装依赖，或通过命令行运行:\n' +
      `cd "${AGENT_DIR}"\n` +
      'set PYTHONPATH=src\n' +
      'python -m uvicorn web.server:app --host 127.0.0.1 --port 8765'
    );
    app.quit();
  }
});

app.on('window-all-closed', () => {
  stopFastAPI();
  app.quit();
});

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

// macOS: 点击 Dock 图标重新创建窗口
app.on('activate', () => {
  if (mainWindow === null) {
    createWindow();
  }
});

// 防止多实例（可选）
const gotLock = app.requestSingleInstanceLock();
if (!gotLock) {
  app.quit();
} else {
  app.on('second-instance', () => {
    if (mainWindow) {
      if (mainWindow.isMinimized()) mainWindow.restore();
      mainWindow.focus();
    }
  });
}