const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const morgan = require('morgan');
const rateLimit = require('express-rate-limit');
const xss = require('xss-clean');
const hpp = require('hpp');
const swaggerUi = require('swagger-ui-express');
const swaggerSpec = require('./config/swagger');

console.log('🔧 初始化Express应用...');

const { globalErrorHandler, notFound } = require('./utils/errors');

// 检查是否为无数据库模式
const NO_DB_MODE = process.env.NO_DB_MODE === 'true';

let authRoutes, userRoutes, travelRoutes, animalRoutes, orderRoutes, adminRoutes, travelRegistrationRoutes, promotionRoutes, merchantRoutes, travelsRoutes;

// 路由导入
if (NO_DB_MODE) {
  console.log('⚠️  无数据库模式：将使用模拟路由');
} else {
  console.log('✅ 数据库模式：加载实际路由');
  authRoutes = require('./routes/auth');
  userRoutes = require('./routes/user');
  travelRoutes = require('./routes/travel');
  travelsRoutes = require('./routes/travels'); // 新增travels路由
  animalRoutes = require('./routes/animal');
  orderRoutes = require('./routes/order');
  adminRoutes = require('./routes/admin'); // 新增管理员路由
  travelRegistrationRoutes = require('./routes/travelRegistration'); // 旅行报名路由
  paymentRoutes = require('./routes/payment-simple');
  animalClaimRoutes = require('./routes/animalClaim-simple'); // 动物认领路由（简化版）
  promotionRoutes = require('./routes/promotion'); // 促销活动路由
  merchantRoutes = require('./routes/merchant'); // 商户路由
}

const app = express();

console.log('✅ Express应用初始化完成');

// 安全中间件
app.use(helmet());

// CORS配置
app.use(cors({
  origin: process.env.NODE_ENV === 'production' 
    ? ['https://your-domain.com'] 
    : [
        'https://www.jiebanke.com', 
        'https://admin.jiebanke.com', 
        'https://webapi.jiebanke.com',
        'http://localhost:3150',  // 管理后台本地开发地址
        'http://localhost:3000',  // 备用端口
        'http://localhost:3200',  // 备用端口
        'http://127.0.0.1:3150',  // 备用地址
        'http://127.0.0.1:3000',  // 备用地址
        'http://127.0.0.1:3200'   // 备用地址
      ],
  credentials: true,
  methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
  allowedHeaders: ['Content-Type', 'Authorization', 'X-Requested-With']
}));

// 请求日志
if (process.env.NODE_ENV === 'development') {
  app.use(morgan('dev'));
} else {
  app.use(morgan('combined'));
}

// 请求频率限制
const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15分钟
  max: process.env.NODE_ENV === 'production' ? 100 : 1000, // 生产环境100次，开发环境1000次
  message: {
    success: false,
    code: 429,
    message: '请求过于频繁，请稍后再试',
    timestamp: new Date().toISOString()
  }
});
app.use('/api', limiter);

// 请求体解析
app.use(express.json({ limit: '10kb' }));
app.use(express.urlencoded({ extended: true, limit: '10kb' }));

// 数据清洗
app.use(xss()); // 防止XSS攻击
app.use(hpp({ // 防止参数污染
  whitelist: [
    'page',
    'pageSize',
    'sort',
    'fields',
    'price',
    'rating',
    'distance'
  ]
}));

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

// Swagger文档路由
if (process.env.NODE_ENV === 'development' || process.env.ENABLE_SWAGGER === 'true') {
  app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerSpec));
  console.log('📚 Swagger文档已启用: https://webapi.jiebanke.com/api-docs');
}

// 健康检查路由
app.get('/health', (req, res) => {
  res.status(200).json({
    status: 'OK',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    environment: process.env.NODE_ENV || 'development',
    noDbMode: NO_DB_MODE
  });
});

// API根路由
app.get('/api/v1', (req, res) => {
  res.status(200).json({
    success: true,
    message: '杰伴客API服务运行正常',
    version: '1.0.0',
    timestamp: new Date().toISOString(),
    endpoints: {
      auth: '/api/v1/auth',
      users: '/api/v1/users',
      travel: '/api/v1/travel',
      animals: '/api/v1/animals',
      orders: '/api/v1/orders',
      payments: '/api/v1/payments',
      animalClaims: '/api/v1/animal-claims',
      admin: '/api/v1/admin',
      travelRegistration: '/api/v1/travel-registration',
      promotion: '/api/v1/promotion'
    },
    documentation: 'https://webapi.jiebanke.com/api-docs'
  });
});

// 系统统计路由
app.get('/system-stats', (req, res) => {
  const stats = {
    status: 'OK',
    timestamp: new Date().toISOString(),
    environment: process.env.NODE_ENV || 'development',
    nodeVersion: process.version,
    memoryUsage: process.memoryUsage(),
    uptime: process.uptime(),
    cpuCount: require('os').cpus().length,
    platform: process.platform,
    architecture: process.arch,
    noDbMode: NO_DB_MODE
  };
  
  res.status(200).json(stats);
});

// 无数据库模式下的模拟路由
if (NO_DB_MODE) {
  // 认证路由
  app.use('/api/v1/auth', (req, res) => {
    if (req.method === 'POST' && req.path === '/login') {
      // 模拟登录响应
      res.status(200).json({
        success: true,
        message: '模拟登录成功',
        data: {
          token: 'mock-jwt-token',
          user: {
            id: 1,
            username: 'mockuser',
            email: 'mock@example.com',
            role: 'user'
          }
        }
      });
    } else {
      res.status(503).json({
        success: false,
        message: '当前为无数据库模式，该功能不可用'
      });
    }
  });
  
  // 其他路由的通用响应
  app.use('/api/v1/users', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，用户管理功能不可用'
    });
  });
  
  app.use('/api/v1/travel', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，旅行相关功能不可用'
    });
  });
  
  app.use('/api/v1/animals', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，动物相关功能不可用'
    });
  });
  
  app.use('/api/v1/orders', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，订单相关功能不可用'
    });
  });
  
  app.use('/api/v1/travel-registration', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，旅行报名功能不可用'
    });
  });
  
  app.use('/api/v1/payments', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，支付功能不可用'
    });
  });
  
  app.use('/api/v1/animal-claims', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，动物认领功能不可用'
    });
  });
  
  app.use('/api/v1/admin', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，管理员功能不可用'
    });
  });
  
  app.use('/api/v1/promotion', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，促销活动功能不可用'
    });
  });
  
  app.use('/api/v1/merchants', (req, res) => {
    res.status(503).json({
      success: false,
      message: '当前为无数据库模式，商户功能不可用'
    });
  });
} else {
  // API路由
  app.use('/api/v1/auth', authRoutes);
  app.use('/api/v1/users', userRoutes);
  app.use('/api/v1/travel', travelRoutes);
  app.use('/api/v1/travels', travelsRoutes); // 新增travels路由
  app.use('/api/v1/animals', animalRoutes);
  app.use('/api/v1/orders', orderRoutes);
  app.use('/api/v1/payments', paymentRoutes);
  // 动物认领路由
  app.use('/api/v1/animal-claims', animalClaimRoutes);
  // 管理员路由
  app.use('/api/v1/admin', adminRoutes);
  // 旅行报名路由
  app.use('/api/v1/travel-registration', travelRegistrationRoutes);
  // 促销活动路由
  app.use('/api/v1/promotion', promotionRoutes);
  // 商户路由
  app.use('/api/v1/merchants', merchantRoutes);
}

// 404处理
app.use('*', notFound);

// 全局错误处理
app.use(globalErrorHandler);

console.log('✅ 应用配置完成');

module.exports = app;