import express, { Request, Response, NextFunction } from 'express';
import cors from 'cors';
import swaggerUi from 'swagger-ui-express';
import config from './config';
import { swaggerSpec } from './config/swagger';

// Routes
import publicRoutes from './routes/public';
import webhookRoutes from './routes/webhooks';
import userRoutes from './routes/user';
import adminRoutes from './routes/admin';

// Middleware
import { generalRateLimiter } from './middleware/rateLimit';

const app = express();

// Trust proxy for rate limiting (needed when behind reverse proxy)
if (config.app.nodeEnv === 'production') {
  app.set('trust proxy', 1); // Trust first proxy
}

// CORS configuration
app.use(cors({
  origin: config.app.nodeEnv === 'production' 
    ? config.cors.allowedOrigins 
    : true,
  credentials: true,
}));

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

// General rate limiting
app.use(generalRateLimiter);

// Swagger API Documentation
app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerSpec, {
  customCss: '.swagger-ui .topbar { display: none }',
  customSiteTitle: 'Lightning Lottery API Docs',
}));

// Swagger JSON endpoint
app.get('/api-docs.json', (req: Request, res: Response) => {
  res.setHeader('Content-Type', 'application/json');
  res.send(swaggerSpec);
});

// Health check endpoint
app.get('/health', async (req: Request, res: Response) => {
  const { db } = await import('./database');
  const { lnbitsService } = await import('./services/lnbits');

  const dbHealth = await db.healthCheck();
  const lnbitsHealth = await lnbitsService.healthCheck();

  const healthy = dbHealth && lnbitsHealth;

  res.status(healthy ? 200 : 503).json({
    version: '1.0',
    status: healthy ? 'healthy' : 'unhealthy',
    checks: {
      database: dbHealth ? 'ok' : 'failed',
      lnbits: lnbitsHealth ? 'ok' : 'failed',
    },
    timestamp: new Date().toISOString(),
  });
});

// API routes
app.use('/', publicRoutes);
app.use('/webhooks', webhookRoutes);
app.use('/', userRoutes);
app.use('/admin', adminRoutes);

// 404 handler
app.use((req: Request, res: Response) => {
  res.status(404).json({
    version: '1.0',
    error: 'NOT_FOUND',
    message: 'Endpoint not found',
  });
});

// Error handler
app.use((err: Error, req: Request, res: Response, next: NextFunction) => {
  console.error('Unhandled error:', err);
  
  res.status(500).json({
    version: '1.0',
    error: 'INTERNAL_ERROR',
    message: config.app.nodeEnv === 'production' 
      ? 'An internal error occurred' 
      : err.message,
  });
});

export default app;