agora-ai/backend/src/index.js

import express from 'express';
import cors from 'cors';
import helmet from 'helmet';
import dotenv from 'dotenv';
import { createServer } from 'http';
import { WebSocketServer } from 'ws';
import rateLimit from 'express-rate-limit';
import { parse } from 'url';
import db from './db/schema.js';
import collaborateRoutes from './routes/collaborate.js';
import collaborativeOrchestrator from './services/collaborativeOrchestrator.js';

dotenv.config();

const app = express();
const server = createServer(app);
const wss = new WebSocketServer({ server });

const PORT = process.env.PORT || 3000;

// Middleware
app.use(helmet());
app.use(cors({
  origin: process.env.FRONTEND_URL || 'http://localhost:5173',
  credentials: true
}));
app.use(express.json());

// Rate limiting
const limiter = rateLimit({
  windowMs: 60 * 1000, // 1 minute
  max: 10 // 10 requests per minute
});
app.use('/api', limiter);

// WebSocket connection handling
wss.on('connection', (ws, req) => {
  const { query } = parse(req.url, true);
  const sessionId = query.sessionId ? parseInt(query.sessionId) : null;

  console.log('WebSocket connection', sessionId ? `session ${sessionId}` : 'established');

  if (sessionId) {
    collaborativeOrchestrator.registerWSClient(sessionId, ws);

    ws.send(JSON.stringify({
      type: 'connected',
      sessionId,
      message: 'Connected to session'
    }));
  }

  ws.on('message', (message) => {
    try {
      const data = JSON.parse(message.toString());
      console.log('Received:', data);

      if (data.type === 'subscribe' && data.sessionId) {
        collaborativeOrchestrator.registerWSClient(parseInt(data.sessionId), ws);
        ws.send(JSON.stringify({
          type: 'subscribed',
          sessionId: data.sessionId
        }));
      }
    } catch (error) {
      console.error('WebSocket message error:', error);
    }
  });

  ws.on('close', () => {
    if (sessionId) {
      collaborativeOrchestrator.unregisterWSClient(sessionId, ws);
    }
    console.log('WebSocket closed');
  });
});

// Routes
app.get('/api/health', (req, res) => {
  res.json({ status: 'ok' });
});

app.use('/api/collaborate', collaborateRoutes);

// Start server
server.listen(PORT, () => {
  console.log(`Agora AI Backend running on port ${PORT}`);
  console.log(`WebSocket server ready`);
});