server.js

const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const rateLimit = require('express-rate-limit');
const http = require('http');
const socketIo = require('socket.io');
require('dotenv').config();

const { testConnection } = require('./config/database');

// Import routes
const authRoutes = require('./routes/auth');
const productRoutes = require('./routes/products');
const inventoryRoutes = require('./routes/inventory');
const orderRoutes = require('./routes/orders');

const app = express();
const server = http.createServer(app);
const io = socketIo(server, {
  cors: {
    origin: process.env.CLIENT_URL || "http://localhost:3000",
    methods: ["GET", "POST"]
  }
});

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

// Rate limiting
const limiter = rateLimit({
  windowMs: 1 * 60 * 1000, // 1 minute
  max: 1000, // limit each IP to 1000 requests per minute (much more generous for development)
  message: 'Too many requests from this IP, please try again later.'
});
app.use('/api/', limiter);

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

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

// Static files
app.use('/uploads', express.static('uploads'));

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

// API routes
app.use('/api/auth', authRoutes);
app.use('/api/products', productRoutes);
app.use('/api/inventory', inventoryRoutes);
app.use('/api/orders', orderRoutes);

// Socket.IO for real-time features
io.on('connection', (socket) => {
  console.log('User connected:', socket.id);

  // Join user to their personal room
  socket.on('join-user-room', (userId) => {
    socket.join(`user-${userId}`);
    console.log(`User ${userId} joined their room`);
  });

  // Handle order status updates
  socket.on('order-status-update', (data) => {
    const { orderId, status, userId } = data;
    
    // Notify both buyer and seller about order status change
    socket.to(`user-${userId}`).emit('order-updated', {
      orderId,
      status,
      timestamp: new Date().toISOString()
    });
  });

  // Handle new order notifications
  socket.on('new-order', (data) => {
    const { sellerId, orderId } = data;
    
    // Notify seller about new order
    socket.to(`user-${sellerId}`).emit('new-order-notification', {
      orderId,
      timestamp: new Date().toISOString()
    });
  });

  socket.on('disconnect', () => {
    console.log('User disconnected:', socket.id);
  });
});

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

// Error handling middleware
app.use((err, req, res, next) => {
  console.error('Error:', err);
  
  if (err.type === 'entity.parse.failed') {
    return res.status(400).json({ message: 'Invalid JSON format' });
  }
  
  res.status(500).json({ 
    message: 'Internal server error',
    ...(process.env.NODE_ENV === 'development' && { error: err.message })
  });
});

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

const PORT = process.env.PORT || 5000;

// Start server
const startServer = async () => {
  try {
    // Test database connection
    await testConnection();
    
    server.listen(PORT, () => {
      console.log(`🚀 Server running on port ${PORT}`);
      console.log(`📊 Health check: http://localhost:${PORT}/health`);
      console.log(`🌍 Environment: ${process.env.NODE_ENV || 'development'}`);
    });
  } catch (error) {
    console.error('Failed to start server:', error);
    process.exit(1);
  }
};

// Handle graceful shutdown
process.on('SIGTERM', () => {
  console.log('SIGTERM received. Shutting down gracefully...');
  server.close(() => {
    console.log('Process terminated');
  });
});

process.on('SIGINT', () => {
  console.log('SIGINT received. Shutting down gracefully...');
  server.close(() => {
    console.log('Process terminated');
  });
});

startServer();