require('dotenv').config({ path: require('path').join(__dirname, '../.env') });
const express = require('express');
const session = require('express-session');
const helmet = require('helmet');
const cors = require('cors');
const logger = require('./config/logger');
const sessionConfig = require('./config/session');
const { testConnection } = require('./config/database');
const errorHandler = require('./middlewares/errorHandler');
const { apiLimiter } = require('./middlewares/rateLimiter');

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

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

// Dynamic CORS configuration (will be updated from settings)
let corsOptions = {
  origin: process.env.FRONTEND_URL || 'http://localhost:5173',
  credentials: true,
};

app.use((req, res, next) => {
  cors(corsOptions)(req, res, next);
});

// Function to update CORS from database
const updateCorsFromSettings = async () => {
  try {
    const { Settings } = require('./models');
    const corsEnabledSetting = await Settings.findOne({ where: { key: 'cors_enabled' } });
    const frontendUrlSetting = await Settings.findOne({ where: { key: 'frontend_url' } });
    
    if (corsEnabledSetting && corsEnabledSetting.value === 'true' && frontendUrlSetting) {
      corsOptions.origin = frontendUrlSetting.value;
      logger.info(`CORS enabled for: ${frontendUrlSetting.value}`);
    } else {
      // Default: allow both frontend and backend on same origin
      corsOptions.origin = process.env.FRONTEND_URL || 'http://localhost:5173';
    }
  } catch (error) {
    logger.warn('Could not load CORS settings from database, using defaults');
  }
};

// Update CORS on startup (with delay to ensure DB is ready)
setTimeout(updateCorsFromSettings, 2000);

// Export for use in settings controller
app.updateCorsSettings = updateCorsFromSettings;

// Body parsing middleware
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// Serve static files (landing page and frontend build)
const path = require('path');
app.use(express.static(path.join(__dirname, 'public')));

// Serve landing page at /landing route
app.get('/landing', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'landing.html'));
});

// Session middleware
app.use(session(sessionConfig));

// Rate limiting
app.use('/api', apiLimiter);

// Request logging
app.use((req, res, next) => {
  logger.info(`${req.method} ${req.path}`, {
    ip: req.ip,
    userAgent: req.get('user-agent'),
  });
  next();
});

// Health check
app.get('/health', (req, res) => {
  res.json({
    success: true,
    message: 'Server is running',
    timestamp: new Date().toISOString(),
  });
});

// API Routes
app.use('/api/auth', require('./routes/auth.routes'));
app.use('/api/companies', require('./routes/company.routes'));
app.use('/api/tokens', require('./routes/token.routes'));
app.use('/api/templates', require('./routes/template.routes'));
app.use('/api/settings', require('./routes/settings.routes'));
app.use('/api/ollama', require('./routes/ollama.routes'));
app.use('/api/stats', require('./routes/stats.routes'));

// Public tracking route (no rate limit on this specific route)
app.use('/t', require('./routes/tracking.routes'));

// Serve frontend SPA (must be after API routes)
app.get('*', (req, res, next) => {
  // Skip if it's an API route, tracking route, or landing page
  if (req.path.startsWith('/api') || req.path.startsWith('/t') || req.path.startsWith('/landing') || req.path.startsWith('/health')) {
    return next();
  }
  
  // Serve frontend index.html for all other routes
  const frontendPath = path.join(__dirname, 'public', 'dist', 'index.html');
  res.sendFile(frontendPath, (err) => {
    if (err) {
      // If frontend build doesn't exist, return 404
      next();
    }
  });
});

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

// Error handler (must be last)
app.use(errorHandler);

// Start server
const startServer = async () => {
  try {
    // Test database connection
    await testConnection();
    
    // Start listening
    app.listen(PORT, () => {
      logger.info(`🚀 Server is running on port ${PORT}`);
      logger.info(`📊 Environment: ${process.env.NODE_ENV || 'development'}`);
      logger.info(`🔗 Health check: http://localhost:${PORT}/health`);
      console.log(`\n✨ Oltalama Backend Server Started!`);
      console.log(`🌐 API: http://localhost:${PORT}/api`);
      console.log(`🎯 Tracking: http://localhost:${PORT}/t/:token\n`);
    });
  } catch (error) {
    logger.error('Failed to start server:', error);
    process.exit(1);
  }
};

startServer();

module.exports = app;