// main.js —— Electron 主进程(瘦客户端壳)。
// 启动流程:读后端各服务地址配置 → 起本地静态 + /api 反代服务器(仅监听 127.0.0.1)→ 建窗口加载。
// 前端 ui/ 源码零改动:相对路径 /api 与 SSE 流靠「同源」天然可用,后端 CORS 也无需改。
// 反代功能上只走 bff(BFF 是前端唯一入口);qa/rag/vstore/paper/bioflow 地址在设置里可改、持久化,
// 实际的各服务再路由由 BFF 自己的 config/.env 完成(见 README)。
const { app, BrowserWindow, Menu, ipcMain, dialog } = require('electron');
const path = require('path');
const fs = require('fs');
const { createServer } = require('./server');
const { loadServices, saveServices } = require('./config');

let mainWindow = null;
let settingsWindow = null;
let server = null;
let currentOrigin = null;

/** 前端构建产物目录:开发态在 desktop/renderer-dist,打包态在 resources/renderer-dist(extraResources)。 */
function staticDir() {
  return app.isPackaged
    ? path.join(process.resourcesPath, 'renderer-dist')
    : path.join(__dirname, 'renderer-dist');
}

function startServer(bffUrl) {
  return new Promise((resolve, reject) => {
    const srv = createServer({ staticDir: staticDir(), backendUrl: bffUrl });
    srv.once('error', reject);
    srv.listen(0, '127.0.0.1', () => {
      server = srv;
      resolve(`http://127.0.0.1:${srv.address().port}`);
    });
  });
}

function stopServer() {
  if (server) {
    server.close();
    server = null;
  }
}

async function restartServer(bffUrl) {
  stopServer();
  currentOrigin = await startServer(bffUrl);
  return currentOrigin;
}

function createMainWindow() {
  mainWindow = new BrowserWindow({
    width: 1280,
    height: 860,
    minWidth: 960,
    minHeight: 640,
    title: '海古纪 PlantAI',
    backgroundColor: '#0f1115',
    show: false,
    webPreferences: {
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: true,
    },
  });
  mainWindow.loadURL(currentOrigin);
  mainWindow.once('ready-to-show', () => mainWindow.show());
  mainWindow.on('closed', () => {
    mainWindow = null;
  });
}

function openSettingsWindow() {
  if (settingsWindow) {
    settingsWindow.focus();
    return;
  }
  settingsWindow = new BrowserWindow({
    width: 500,
    height: 560,
    resizable: false,
    minimizable: false,
    maximizable: false,
    title: '后端服务设置',
    parent: mainWindow || undefined,
    modal: !!mainWindow,
    autoHideMenuBar: true,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: true,
    },
  });
  settingsWindow.loadFile(path.join(__dirname, 'settings.html'));
  settingsWindow.on('closed', () => {
    settingsWindow = null;
  });
}

function buildMenu() {
  const template = [
    {
      label: '设置',
      submenu: [
        { label: '后端服务地址…', click: openSettingsWindow },
        { type: 'separator' },
        { role: 'reload' },
        { role: 'toggleDevTools' },
        { type: 'separator' },
        { role: 'quit', label: '退出' },
      ],
    },
  ];
  if (process.platform === 'darwin') {
    template.unshift({
      label: app.name,
      submenu: [{ role: 'about' }, { type: 'separator' }, { role: 'quit' }],
    });
  }
  Menu.setApplicationMenu(Menu.buildFromTemplate(template));
}

app.whenReady().then(async () => {
  buildMenu();

  const dir = staticDir();
  if (!fs.existsSync(path.join(dir, 'index.html'))) {
    dialog.showErrorBox(
      '缺少前端构建产物',
      `未找到 ${dir}\n\n请先构建前端:\n  cd ui && npm run build\n  cd desktop && npm run build:ui`
    );
    app.quit();
    return;
  }

  ipcMain.handle('desktop:get-config', () => loadServices(app.getPath('userData')));
  ipcMain.handle('desktop:set-config', async (_event, services) => {
    // 用户显式保存后,文件配置优先于环境变量(否则 env 会一直盖住用户设置)
    delete process.env.PLANTAI_BFF_URL;
    const saved = saveServices(app.getPath('userData'), services);
    await restartServer(saved.bff);
    if (mainWindow) await mainWindow.loadURL(currentOrigin);
    return saved;
  });

  const services = loadServices(app.getPath('userData'));
  currentOrigin = await startServer(services.bff);
  createMainWindow();

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

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

app.on('will-quit', stopServer);