const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const session = require('express-session');
const morgan = require('morgan');

// Import database (uses environment variables from docker-compose.yml)
const database = require('./config/database');

// Import services
const EnhancedDiffProcessingService = require('./services/enhanced-diff-processing.service');

// Import routes
const githubRoutes = require('./routes/github-integration.routes');
const githubOAuthRoutes = require('./routes/github-oauth');
const webhookRoutes = require('./routes/webhook.routes');
const vcsRoutes = require('./routes/vcs.routes');

// Import new enhanced routes
const commitsRoutes = require('./routes/commits.routes');
const oauthProvidersRoutes = require('./routes/oauth-providers.routes');
const enhancedWebhooksRoutes = require('./routes/enhanced-webhooks.routes');

const app = express();
const PORT = process.env.PORT || 8012;

// Middleware
app.use(helmet());
app.use(cors());
app.use(morgan('combined'));
// Preserve raw body for webhook signature verification

app.use(express.json({
  limit: '10mb',
  verify: (req, res, buf) => {
    req.rawBody = buf;
  }
}));

app.use(express.urlencoded({
  extended: true,
  verify: (req, res, buf) => {
    req.rawBody = buf;
  }
}));

// Session middleware
app.use(session({
  secret: process.env.SESSION_SECRET || 'git-integration-secret-key-2024',
  resave: false,
  saveUninitialized: false,
  cookie: {
    secure: false, // Set to true if using HTTPS
    httpOnly: true,
    maxAge: 24 * 60 * 60 * 1000 // 24 hours
  }
}));

// Routes
app.use('/api/github', githubRoutes);
app.use('/api/github', githubOAuthRoutes);
app.use('/api/github', webhookRoutes);
app.use('/api/vcs', vcsRoutes);

// Enhanced routes
app.use('/api/commits', commitsRoutes);
app.use('/api/oauth', oauthProvidersRoutes);
app.use('/api/webhooks', enhancedWebhooksRoutes);

// Health check endpoint
app.get('/health', (req, res) => {
  res.status(200).json({
    status: 'healthy',
    service: 'git-integration',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    version: '1.0.0'
  });
});

// API health check endpoint for gateway compatibility
app.get('/api/github/health', (req, res) => {
  res.status(200).json({
    status: 'healthy',
    service: 'git-integration',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    version: '1.0.0'
  });
});

// Root endpoint
app.get('/', (req, res) => {
  res.json({
    message: 'Git Integration Service',
    version: '1.0.0',
    endpoints: {
      health: '/health',
      github: '/api/github',
      oauth: '/api/github/auth',
      webhook: '/api/github/webhook',
      vcs: '/api/vcs/:provider',
      commits: '/api/commits',
      oauth_providers: '/api/oauth',
      enhanced_webhooks: '/api/webhooks'
    }
  });
});

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

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

// Graceful shutdown
process.on('SIGTERM', async () => {
  console.log('SIGTERM received, shutting down gracefully');
  await database.close();
  process.exit(0);
});

process.on('SIGINT', async () => {
  console.log('SIGINT received, shutting down gracefully');
  await database.close();
  process.exit(0);
});

// Initialize services
async function initializeServices() {
  try {
    // Initialize diff processing service
    const diffProcessingService = new EnhancedDiffProcessingService();
    await diffProcessingService.initialize();
    
    // Start background diff processing if enabled
    if (process.env.ENABLE_BACKGROUND_DIFF_PROCESSING !== 'false') {
      const processingInterval = parseInt(process.env.DIFF_PROCESSING_INTERVAL_MS) || 30000;
      diffProcessingService.startBackgroundProcessing(processingInterval);
      console.log('🔄 Background diff processing started');
    }
    
    console.log('✅ All services initialized successfully');
  } catch (error) {
    console.error('❌ Error initializing services:', error);
  }
}

// Start server
app.listen(PORT, '0.0.0.0', async () => {
  console.log(`🚀 Git Integration Service running on port ${PORT}`);
  console.log(`📊 Health check: http://localhost:8000/health`);
  console.log(`🔗 GitHub API: http://localhost:8000/api/github`);
  console.log(`📝 Commits API: http://localhost:8000/api/commits`);
  console.log(`🔐 OAuth API: http://localhost:8000/api/oauth`);
  console.log(`🪝 Enhanced Webhooks: http://localhost:8000/api/webhooks`);
  
  // Initialize services after server starts
  await initializeServices();
});

module.exports = app;