const express = require('express');
const WebSocket = require('ws');
const cors = require('cors');
const helmet = require('helmet');
const rateLimit = require('express-rate-limit');
const { spawn } = require('child_process');
const jwt = require('jsonwebtoken');
const redis = require('redis');
require('dotenv').config();
const app = express();
const PORT = process.env.PORT || 3001;
// Middleware
app.use(helmet());
app.use(cors());
app.use(express.json());
app.use(rateLimit({ windowMs: 15 * 60 * 1000, max: 100 })); // Rate limiting
// Redis for caching
const redisClient = redis.createClient();
redisClient.connect();
// WebSocket Server
const wss = new WebSocket.Server({ port: 8080 });
wss.on('connection', (ws) => {
console.log('Client connected');
ws.on('message', (message) => {
console.log('Received:', message);
});
// Stream sim data
setInterval(() => {
const simData = runSim('quantum_ledger.py'); // Simplified
ws.send(JSON.stringify(simData));
}, 10000);
});
// Auth Middleware
const authenticate = (req, res, next) => {
const token = req.header('Authorization')?.replace('Bearer ', '');
if (!token) return res.status(401).send('Access denied');
try {
req.user = jwt.verify(token, process.env.JWT_SECRET);
next();
} catch (err) {
res.status(400).send('Invalid token');
}
};
// Routes
app.get('/api/sim-data', authenticate, async (req, res) => {
const cached = await redisClient.get('simData');
if (cached) return res.json(JSON.parse(cached));
const data = await runSimAsync('simulations/quantum_ledger.py');
await redisClient.setEx('simData', 300, JSON.stringify(data)); // Cache 5min
res.json(data);
});
app.post('/api/ai-predict', authenticate, async (req, res) => {
const { query } = req.body;
const prediction = await getAIPrediction(query);
res.json({ prediction });
});
app.post('/api/contract-interact', authenticate, async (req, res) => {
// Placeholder for contract calls via ethers
res.json({ status: 'Interaction successful' });
});
// Helper Functions
function runSim(script) {
// Synchronous sim run (for demo)
return { synced: 'data', consensus: 'agreed' };
}
async function runSimAsync(script) {
return new Promise((resolve) => {
const process = spawn('python', [script]);
let data = '';
process.stdout.on('data', (chunk) => data += chunk);
process.on('close', () => resolve(JSON.parse(data || '{}')));
});
}
async function getAIPrediction(query) {
const response = await axios.post('https://api.openai.com/v1/chat/completions', {
model: 'gpt-3.5-turbo',
messages: [{ role: 'user', content: query }]
}, {
headers: { 'Authorization': `Bearer ${process.env.OPENAI_API_KEY}` }
});
return response.data.choices[0].message.content;
}
app.listen(PORT, () => {
console.log(`Gaia Backend running on port ${PORT}`);
});
