import express from 'express';
import cors from 'cors';
import helmet from 'helmet';
import rateLimit from 'express-rate-limit';
import dotenv from 'dotenv';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';
import { contactRouter } from './routes/contact.js';
import { errorHandler, notFoundHandler } from './middleware/errorHandlers.js';
import { requestLogger } from './middleware/logger.js';
import { initializeEmailService } from './services/emailService.js';

// Get the directory of the current module
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

// Load environment variables from the backend directory
dotenv.config({ path: join(__dirname, '.env') });

async function startServer() {
  // Initialize email service after environment variables are loaded
  await initializeEmailService();

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

  // Security middleware
  app.use(
    helmet({
      crossOriginResourcePolicy: { policy: 'cross-origin' },
    })
  );

  // CORS configuration
  app.use(
    cors({
      origin: process.env.FRONTEND_URL || 'http://localhost:5173',
      methods: ['GET', 'POST'],
      allowedHeaders: ['Content-Type', 'Authorization'],
      credentials: true,
    })
  );

  // Rate limiting
  const limiter = rateLimit({
    windowMs: parseInt(process.env.RATE_LIMIT_WINDOW_MS) || 15 * 60 * 1000, // 15 minutes
    max: parseInt(process.env.RATE_LIMIT_MAX_REQUESTS) || 5, // limit each IP to 5 requests per windowMs
    message: {
      error: 'Too many requests from this IP, please try again later.',
      retryAfter: Math.ceil(
        (parseInt(process.env.RATE_LIMIT_WINDOW_MS) || 15 * 60 * 1000) / 1000
      ),
    },
    standardHeaders: true,
    legacyHeaders: false,
  });

  app.use('/api/', limiter);

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

  // Request logging
  app.use(requestLogger);

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

  // API routes
  app.use('/api/contact', contactRouter);

  // Error handling middleware
  app.use(notFoundHandler);
  app.use(errorHandler);

  // Start server
  app.listen(PORT, () => {
    console.log(`🚀 Server is running on port ${PORT}`);
    console.log(
      `📧 Email service: ${process.env.EMAIL_SERVICE || 'Not configured'}`
    );
    console.log(`🌍 Environment: ${process.env.NODE_ENV || 'development'}`);
    console.log(
      `🔗 Frontend URL: ${process.env.FRONTEND_URL || 'http://localhost:5173'}`
    );
  });

  // Graceful shutdown
  process.on('SIGTERM', () => {
    console.log('SIGTERM signal received: closing HTTP server');
    process.exit(0);
  });

  process.on('SIGINT', () => {
    console.log('SIGINT signal received: closing HTTP server');
    process.exit(0);
  });
}

// Start the server
startServer().catch((error) => {
  console.error('Failed to start server:', error);
  process.exit(1);
});