index.js

var app = require('express')();
var server = require('http').Server(app);
var io = require('socket.io')(server);
var port = 8888;
var clients = {};

io.on('connection', (socket) => {
    console.log("Server detect a connection")
    
    //Add user to connected clients
    clients[socket.handshake.query.userId] = {
        name:socket.handshake.query.name,
        surname:socket.handshake.query.surname,
        jobTitle:socket.handshake.query.jobTitle,
        socket:socket
    }

    socket.on('join', function (data) {
        console.log("Connection")
        console.log(data)
        socket.join(data.roomId);
        socket.room = data.roomId;
        const sockets = io.of('/').in().adapter.rooms[data.roomId];
        if (sockets.length === 1) {
            socket.emit('init')
        } else {
            if (sockets.length === 2) {
                io.to(data.roomId).emit('ready')
            } else {
                socket.room = null
                socket.leave(data.roomId)
                socket.emit('full')
            }

        }
    });
    socket.on('signal', (data) => {
        io.to(data.room).emit('desc', data.desc)
    })
    socket.on('disconnect', () => {
        const roomId = Object.keys(socket.adapter.rooms)[0]
        if (socket.room) {
            io.to(socket.room).emit('disconnected')
        }
        //Remove user from connected clients
        Object.keys(clients).forEach(userId=>{
            if (clients[userId].socket ===socket){
                delete clients[userId]
            }
        })

    })
});

server.listen(port, () => { console.log("Server is listening") });