server.js

const express = require('express');
const session = require('express-session');
const cors = require('cors');
const bodyParser = require('body-parser');
const path = require('path');
require('dotenv').config();

const app = express();
const PORT = process.env.PORT || 3000;

// HTTP Basic Auth middleware (password only)
const basicAuth = (req, res, next) => {
  const AUTH_PASSWORD = process.env.AUTH_PASSWORD || 'migration2024';
  
  // Get the Authorization header
  const authHeader = req.headers.authorization;
  
  if (!authHeader || !authHeader.startsWith('Basic ')) {
    // Send authentication challenge
    res.set('WWW-Authenticate', 'Basic realm="Email Migration Tool"');
    return res.status(401).send('Authentication required');
  }
  
  // Decode the Base64 encoded credentials
  const base64Credentials = authHeader.split(' ')[1];
  const credentials = Buffer.from(base64Credentials, 'base64').toString('ascii');
  
  // For password-only auth, we expect format: ":password" or "password"
  // Split on : and take the last part as password
  const parts = credentials.split(':');
  const password = parts.length > 1 ? parts.slice(1).join(':') : parts[0];
  
  if (password !== AUTH_PASSWORD) {
    res.set('WWW-Authenticate', 'Basic realm="Email Migration Tool"');
    return res.status(401).send('Invalid password');
  }
  
  next();
};

// Apply Basic Auth to all routes
app.use(basicAuth);

// Middleware
app.use(cors());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(express.static('public'));
app.set('view engine', 'ejs');
app.set('views', path.join(__dirname, 'views'));

// Set up express-ejs-layouts for layout support
const expressLayouts = require('express-ejs-layouts');
app.use(expressLayouts);
app.set('layout', 'layout');

// Session configuration
app.use(session({
  secret: process.env.SESSION_SECRET || 'your-secret-key',
  resave: false,
  saveUninitialized: false,
  cookie: { 
    secure: false, // Set to true if using HTTPS
    maxAge: 24 * 60 * 60 * 1000 // 24 hours
  }
}));

// Database initialization
const db = require('./config/database');
db.init();

// Routes
const authRoutes = require('./routes/auth');
const migrationRoutes = require('./routes/migration');
const apiRoutes = require('./routes/api');
const jobRoutes = require('./routes/jobs');
const pairsRoutes = require('./routes/pairs');

app.use('/auth', authRoutes);
app.use('/migration', migrationRoutes);
app.use('/api', apiRoutes);
app.use('/jobs', jobRoutes);
app.use('/pairs', pairsRoutes);

// Home route
app.get('/', (req, res) => {
  res.render('index', { 
    title: 'Email Migration Tool',
    user: req.session.user 
  });
});

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

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

// 404 handler
app.use((req, res) => {
  res.status(404).render('error', {
    title: '404 - Page Not Found',
    message: 'The page you are looking for does not exist.'
  });
});

// Initialize background processing if enabled
if (process.env.ENABLE_BACKGROUND_PROCESSING !== 'false') {
  const WorkerManager = require('./workers/worker-manager');
  const progressService = require('./services/progress-service');
  const workerManager = new WorkerManager();
  
  // Initialize progress service
  progressService.init();
  
  // Start workers
  const numWorkers = parseInt(process.env.MAX_WORKERS) || 2;
  workerManager.startWorkers(numWorkers);
  workerManager.startHeartbeat();
  
  // Graceful shutdown handling
  process.on('SIGTERM', async () => {
    console.log('🛑 Received SIGTERM, shutting down gracefully...');
    await workerManager.stopAllWorkers();
    process.exit(0);
  });
  
  process.on('SIGINT', async () => {
    console.log('🛑 Received SIGINT, shutting down gracefully...');
    await workerManager.stopAllWorkers();
    process.exit(0);
  });
  
  console.log(`🔧 Background processing enabled with ${numWorkers} workers`);
}

app.listen(PORT, () => {
  console.log(`GW-Migrate server running on port ${PORT}`);
  console.log(`Visit http://localhost:${PORT} to get started`);
});