const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const rateLimit = require('express-rate-limit');
const path = require('path');
const dotenv = require('dotenv');

// 导入路由
const fileRoutes = require('./routes/files');
const conversionRoutes = require('./routes/conversion');
const userRoutes = require('./routes/users');
const systemRoutes = require('./routes/system');

// 导入中间件
const errorHandler = require('./middleware/errorHandler');
const authMiddleware = require('./middleware/auth');

// 加载环境变量
dotenv.config();

const app = express();
const PORT = process.env.PORT || 3001;

// 安全中间件
app.use(helmet());

// CORS配置
app.use(cors({
  origin: process.env.CLIENT_URL || 'http://localhost:3000',
  credentials: true
}));

// 请求限流
const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15分钟
  max: 100, // 每个IP最多100个请求
  message: '请求过于频繁，请稍后再试'
});
app.use('/api/', limiter);

// 解析请求体
app.use(express.json({ limit: '50mb' }));
app.use(express.urlencoded({ extended: true, limit: '50mb' }));

// 静态文件服务
app.use('/uploads', express.static(path.join(__dirname, 'uploads')));

// API路由
app.use('/api/files', fileRoutes);
app.use('/api/convert', conversionRoutes);
app.use('/api/users', userRoutes);
app.use('/api/system', systemRoutes);

// 健康检查端点
app.get('/health', (req, res) => {
  res.json({
    status: 'OK',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    memory: process.memoryUsage()
  });
});

// 错误处理中间件
app.use(errorHandler);

// 404处理
app.use('*', (req, res) => {
  res.status(404).json({
    success: false,
    message: '接口不存在',
    timestamp: new Date().toISOString()
  });
});

// 启动服务器
app.listen(PORT, () => {
  console.log(`🚀 PDF转换工具服务器运行在端口 ${PORT}`);
  console.log(`📊 健康检查: http://localhost:${PORT}/health`);
});

module.exports = app;