Initial commit: Lightning Lottery - Bitcoin Lightning Network powered lottery

Features:
- Lightning Network payments via LNbits integration
- Provably fair draws using CSPRNG
- Random ticket number generation
- Automatic payouts with retry/redraw logic
- Nostr authentication (NIP-07)
- Multiple draw cycles (hourly, daily, weekly, monthly)
- PostgreSQL and SQLite database support
- Real-time countdown and payment animations
- Swagger API documentation
- Docker support

Stack:
- Backend: Node.js, TypeScript, Express
- Frontend: Next.js, React, TailwindCSS, Redux
- Payments: LNbits

back_end/src/app.ts

@@ -0,0 +1,100 @@
+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;
+