const cluster = require('cluster');
const http = require('http');

if (cluster.isPrimary) {
  // Setup sticky session logic
  cluster.schedulingPolicy = cluster.SCHED_NONE;
  
  // Start workers
  const numCPUs = require('os').cpus().length;
  for (let i = 0; i < numCPUs; i++) {
    cluster.fork();
  }
  
  // Create routes based on connection's remote IP
  cluster.on('connection', (connection, address) => {
    // Calculate which worker gets connection based on IP
    const worker = Object.values(cluster.workers)[
      Number(address.toString().split(':')[3]) % Object.keys(cluster.workers).length
    ];
    worker.send('sticky-session:connection', connection);
  });
} else {
  // Worker code
  http.createServer((req, res) => {
    res.end(`Handled by worker ${process.pid}`);
  }).listen(8000, () => {
    console.log(`Worker ${process.pid} listening`);
  });
  
  // Receive sticky connections
  process.on('message', (message, connection) => {
    if (message !== 'sticky-session:connection') return;
    
    // Emulate a connection event on the server
    server.emit('connection', connection);
    connection.resume();
  });
}