server.js

const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const compression = require('compression');
const morgan = require('morgan');
const rateLimit = require('express-rate-limit');
const { createServer } = require('http');
const { Server } = require('socket.io');
require('dotenv').config();

const db = require('./config/database');
const authRoutes = require('./routes/auth');
const userRoutes = require('./routes/users');
const itemRoutes = require('./routes/items');
const swapRoutes = require('./routes/swaps');
const adminRoutes = require('./routes/admin');
const uploadRoutes = require('./routes/upload');
const notificationRoutes = require('./routes/notifications');

const app = express();
const server = createServer(app);
const io = new Server(server, {
  cors: {
    origin: process.env.FRONTEND_URL || "http://localhost:5173",
    methods: ["GET", "POST"]
  }
});

// Security middleware
app.use(helmet());
app.use(compression());

// Rate limiting
const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100, // limit each IP to 100 requests per windowMs
  message: 'Too many requests from this IP, please try again later.'
});
app.use('/api/', limiter);

// CORS configuration
app.use(cors({
  origin: process.env.FRONTEND_URL || "http://localhost:5173",
  credentials: true
}));

// Body parsing middleware
app.use(express.json({ limit: '10mb' }));
app.use(express.urlencoded({ extended: true, limit: '10mb' }));

// Logging
if (process.env.NODE_ENV === 'development') {
  app.use(morgan('dev'));
}

// Socket.IO for real-time features
io.on('connection', (socket) => {
  console.log('User connected:', socket.id);
  
  socket.on('join_user_room', (userId) => {
    socket.join(`user_${userId}`);
    console.log(`User ${userId} joined their room`);
  });
  
  socket.on('disconnect', () => {
    console.log('User disconnected:', socket.id);
  });
});

// Make io available to routes
app.set('io', io);

// Routes
app.use('/api/auth', authRoutes);
app.use('/api/users', userRoutes);
app.use('/api/items', itemRoutes);
app.use('/api/swaps', swapRoutes);
app.use('/api/admin', adminRoutes);
app.use('/api/upload', uploadRoutes);
app.use('/api/notifications', notificationRoutes);

// Health check endpoint
app.get('/api/health', (req, res) => {
  res.json({ 
    status: 'OK', 
    timestamp: new Date().toISOString(),
    environment: process.env.NODE_ENV 
  });
});

// Error handling middleware
app.use((err, req, res, next) => {
  console.error(err.stack);
  
  if (err.name === 'ValidationError') {
    return res.status(400).json({
      success: false,
      message: 'Validation Error',
      errors: err.errors
    });
  }
  
  if (err.name === 'JsonWebTokenError') {
    return res.status(401).json({
      success: false,
      message: 'Invalid token'
    });
  }
  
  res.status(err.status || 500).json({
    success: false,
    message: err.message || 'Internal Server Error'
  });
});

// 404 handler
app.use('*', (req, res) => {
  res.status(404).json({
    success: false,
    message: 'Route not found'
  });
});

const PORT = process.env.PORT || 3000;

server.listen(PORT, () => {
  console.log(`🚀 Server running on port ${PORT}`);
  console.log(`📊 Environment: ${process.env.NODE_ENV}`);
  console.log(`🔗 Frontend URL: ${process.env.FRONTEND_URL}`);
});

module.exports = app;