peerProxy.js

const { WebSocketServer } = require('ws');
const uuid = require('uuid');

class PeerProxy {
  constructor(httpServer) {
    // Create a websocket object
    const wss = new WebSocketServer({ noServer: true });

    // Handle the protocol upgrade from HTTP to WebSocket
    httpServer.on('upgrade', (request, socket, head) => {
      wss.handleUpgrade(request, socket, head, function done(ws) {
        wss.emit('connection', ws, request);
      });
    });

    // Keep track of all the connections so we can forward messages
    let connections = [];

    wss.on('connection', (ws) => {
      const connection = { id: uuid.v4(), alive: true, ws: ws };
      connections.push(connection);

      // Forward messages to everyone except the sender
      ws.on('message', function message(data) {
        connections.forEach((c) => {
          if (c.id !== connection.id) {
            c.ws.send(data);
          }
        });
      });

      // Remove the closed connection so we don't try to forward anymore
      ws.on('close', () => {
        connections.findIndex((o, i) => {
          if (o.id === connection.id) {
            connections.splice(i, 1);
            return true;
          }
        });
      });

      // Respond to pong messages by marking the connection alive
      ws.on('pong', () => {
        connection.alive = true;
      });
    });

    // Keep active connections alive
    setInterval(() => {
      connections.forEach((c) => {
        // Kill any connection that didn't respond to the ping last time
        if (!c.alive) {
          c.ws.terminate();
        } else {
          c.alive = false;
          c.ws.ping();
        }
      });
    }, 10000);
  }
}

module.exports = { PeerProxy };