const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const path = require('path');
require('dotenv').config();

const { sequelize } = require('./config/database');
const authRoutes = require('./routes/auth');
const userRoutes = require('./routes/users');
const courseRoutes = require('./routes/courses');
const enrollmentRoutes = require('./routes/enrollments');
const attendanceRoutes = require('./routes/attendance');
const assignmentRoutes = require('./routes/assignments');

const app = express();
const PORT = process.env.PORT || 5000;

// Middleware
app.use(helmet());
app.use(cors({
  origin: process.env.CORS_ORIGIN || 'http://localhost:3000',
  credentials: true
}));
app.use(express.json({ limit: '10mb' }));
app.use(express.urlencoded({ extended: true, limit: '10mb' }));

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

// Routes
app.use('/api/auth', authRoutes);
app.use('/api/users', userRoutes);
app.use('/api/courses', courseRoutes);
app.use('/api/enrollments', enrollmentRoutes);
app.use('/api/attendance', attendanceRoutes);
app.use('/api/assignments', assignmentRoutes);

// Health check endpoint
app.get('/api/health', (req, res) => {
  res.json({ status: 'OK', message: 'CourseWorx API is running' });
});

// Error handling middleware
app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).json({ 
    error: 'Something went wrong!',
    message: process.env.NODE_ENV === 'development' ? err.message : 'Internal server error'
  });
});

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

// Database connection and server start
const startServer = async () => {
  try {
    await sequelize.authenticate();
    console.log('✅ Database connection established successfully.');
    
    // Sync database (in development)
    if (process.env.NODE_ENV === 'development') {
      await sequelize.sync({ alter: true });
      console.log('✅ Database synchronized.');
    }
    
    app.listen(PORT, () => {
      console.log(`🚀 Server running on port ${PORT}`);
      console.log(`📱 API available at http://localhost:${PORT}/api`);
    });
  } catch (error) {
    console.error('❌ Unable to connect to the database:', error);
    process.exit(1);
  }
};

startServer();