const express = require('express');
const mongoose = require('mongoose');
const session = require('express-session');
const MongoStore = require('connect-mongo');
const bodyParser = require('body-parser');
const cookieParser = require('cookie-parser');
const path = require('path');
const { paginateQuery } = require('./utils/pagination');
const app = express();

// 增强的 MongoDB 连接配置
mongoose.connect('mongodb://127.0.0.1:27017/blog', {  // 使用127.0.0.1而不是localhost
  useNewUrlParser: true,
  useUnifiedTopology: true,
  serverSelectionTimeoutMS: 5000,  // 添加服务器选择超时
  socketTimeoutMS: 45000,         // 添加socket超时
  family: 4                       // 强制使用IPv4
})
    .then(() => {
      console.log('MongoDB 已经连接');
      // 连接成功后启动服务器
      startServer();
    })
    .catch(err => {
      console.error('MongoDB 连接错误:', err);
      process.exit(1); // 如果数据库连接失败，退出应用
    });

// 添加Mongoose连接状态监听
mongoose.connection.on('connecting', () => console.log('正在连接MongoDB...'));
mongoose.connection.on('disconnected', () => console.log('MongoDB 连接断开'));
mongoose.connection.on('reconnected', () => console.log('MongoDB 重新连接'));

// 其他中间件配置
app.set('view engine', 'ejs');
app.set('views', path.join(__dirname, 'views'));
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use(cookieParser());

// 增强的session配置
app.use(session({
  secret: 'chenlilong_blog_secret',
  resave: false,
  saveUninitialized: false,
  store: MongoStore.create({
    mongoUrl: 'mongodb://127.0.0.1:27017/blog',
    ttl: 24 * 60 * 60, // 1天
    autoRemove: 'native' // 自动清理过期session
  }),
  cookie: {
    maxAge: 1000 * 60 * 60 * 24,
    httpOnly: true,
    secure: process.env.NODE_ENV === 'production'
  }
}));

// 路由配置
app.get('/', async (req, res) => {
  try {
    const Post = require('./models/Post');
    const Link = require('./models/Link');
    const { paginateQuery } = require('./utils/pagination');
    
    // 获取分页参数
    const page = parseInt(req.query.page) || 1;
    const limit = 5; // 每页显示5篇文章
    
    // 获取博客文章（带分页，只获取已发布的文章）
    const postsResult = await paginateQuery(
      Post, 
      { isPublished: true }, // 只显示已发布的文章
      { sort: { isTop: -1, createdAt: -1 } }, // 置顶文章优先，然后按时间倒序
      page, 
      limit
    );
    
    // 获取所有友情链接
    const links = await Link.find().sort({ order: 1, createdAt: -1 });
    
    res.render('user/index', { 
      user: req.session.user || null,
      posts: postsResult.data,
      links: links,
      pagination: postsResult.pagination,
      baseUrl: '/',
      query: {}
    });
  } catch (error) {
    console.error('获取首页数据失败:', error);
    res.render('user/index', { 
      user: req.session.user || null,
      posts: [],
      links: [],
      pagination: { currentPage: 1, totalPages: 1, total: 0 },
      baseUrl: '/',
      query: {}
    });
  }
});

const userAuthRouter = require('./routes/user/auth');
app.use('/', userAuthRouter);
const adminRouter = require('./routes/admin/index');
app.use('/admin', adminRouter);

app.use((req, res) => {
  res.status(404).send('404 Not Found');
});

// 将服务器启动封装为函数
function startServer() {
  const PORT = process.env.PORT || 3001;
  app.listen(PORT, () => {
    console.log(`Server running at http://localhost:${PORT}`);
  });
}