app.js

var express = require('express');
var app = express();

var http = require('http').Server(app);
var socket_io = require('socket.io');
var io = socket_io(http);

var users = require('./users');
var logger = require('./logger');

app.use('/static', express.static(__dirname + '/public'));

app.get('/', function(req, res) {
    logger.log('[New HTTP connection]');
    res.sendFile(__dirname + '/index.html');
});

io.on('connection', function(socket) {
    logger.log('[New socket created]', socket.id);

    var user;

    socket.on('user joined', function(userInfo) {
        user = users.addUser(userInfo, socket).userInfo;
        logger.log('[User joined]', user.name);
    });

    socket.on('chat message', function(msg) {
        if (!user) {
            socket.emit('user not joined');
            return;
        }
        logger.log('[New message]', '[from: ' + user.name + ' ]', msg.message);
        socket.broadcast.emit('new message', {
            timestamp: msg.timestamp,
            message: msg.message,
            socket_id: socket.id,
            user: user
        });
    });

    socket.on('user name changed', function (new_name) {
        if (!new_name.length) {
            return;
        }
        var old_name = user.name;
        user = users.changeName(socket.id, new_name).userInfo;
        logger.log('[User name has been changed]', old_name, new_name);
    });

    socket.on('disconnect', function() {
        var disconnectedUser = users.removeUserBySocket(socket.id);
        if (!disconnectedUser) {
            return;
        }
        logger.log('[User has been left]', disconnectedUser.userInfo.name || user.socket.id);
    });
});

http.listen(3000, function() {
    console.log("Server listening 3000 port");
});