server.js

var connect = require('connect');
var WebSocketServer = require('ws').Server;
var Serializer = require('./lib/serializer.js');
var Config = require('./lib/config.js');
var Player = new require('./lib/player.js');

var server = connect.createServer();
server.use(connect.static(__dirname));
server.use(require('browserify')({
    require: ['bison', __dirname + '/lib/serializer', __dirname + '/lib/config'],
    mount : '/browserify.js',
}));
server.listen(Config.port);

var players = [];
var wss = new WebSocketServer({server: server});
WebSocketServer.prototype.broadcast = function(data, sender) {
  for(var i in this.clients){
    var receiver = this.clients[i];
    if(sender === undefined || sender.sessionId != receiver.sessionId){
      receiver.send(data);
    }
  }
};

wss.on('connection', function(client){
  addPlayer(client);
  sendPing(client);
  initializeRestart();

  client.on('message', function(data){
    var msg = Serializer.deserialize(data);
    // TODO: check if valid before sending data to clients
    if (msg.t) {
      switch (msg.t) {
        case Serializer.MSG_PLAYER_POSITION:
          msg["i"] = getPlayerId(client.sessionId);
          wss.broadcast(Serializer.serialize(msg.t, msg), client);
          break;
        case Serializer.MSG_NEW_SHELL:
          msg.tankId = getPlayerId(client.sessionId);
          wss.broadcast(Serializer.serialize(msg.t, msg), client);
          break;
        case Serializer.MSG_PING:
          var now = Date.now();
          console.log("Ping[" + getPlayerId(client.sessionId) + "]: " + (now - msg.time) + "ms");
          sendPing(client);
          break;
        default:
          console.log("unknown message:" + msg);
      }
    }
  });

  client.on('close',function(){
    console.log('Client disconnected');
    removePlayer(client.sessionId);
  });
});

// removes player id so server does not send it for new players
var removePlayer = function(sid){
  var msg = Serializer.serialize(Serializer.MSG_GONE_PLAYER, {i: getPlayerId(sid)});
  wss.broadcast(msg);
  for (var i=0; i < players.length; i++) {
    if(players[i].sid == sid){
      players.splice(i, 1);
      break;
    }
  }
  console.log(players.length + " players left");
};

// let new player know about existing players
// TODO: not efficient, send in one message
var introduceExistingSprites = function(client){
  for (var x=0; x < players.length; x++) {
    var sp = Serializer.serialize(Serializer.MSG_NEW_PLAYER, {i: players[x].id});
    client.send(sp);
  }
};

var getPlayerBySid = function(sid){
  for (var i=0; i < players.length; i++) {
    if(players[i].sid == sid){
      return players[i];
    }
  }
  console.log("Player does not exist!" + sid);
  return null;
};

// return "internal" player id given client's sessionId
var getPlayerId = function(sid){
  var player = getPlayerBySid(sid);
  if (player) {
    return player.id;
  }
  return NaN;
};

var addPlayer = function(client){
  client.sessionId = Math.floor((1 + Math.random()) * 0x1000000).toString(16);
  // notify everyone about new player, pass player id
  var p = new Player(client.sessionId);
  var pser = Serializer.serialize(Serializer.MSG_NEW_PLAYER, {i: p.id});
  // notify everyone except new player
  wss.broadcast(pser, client.sessionId);
  // notify new player about existing game objects and positions
  introduceExistingSprites(client);
  players.push(p);
  console.log("Player added " + p.id);
};

var sendPing = function(client) {
  setTimeout(function() {
    if (getPlayerBySid(client.sessionId)){
      var timestamp = String(Date.now());
      client.send(Serializer.serialize(Serializer.MSG_PING, {time: timestamp}));
    }
  }, 3000);
};

var initializeRestart = function(){
  var after = 1;
  // if (players.length > 2) {
  //   after = 30;
  // };
  var msg = Serializer.serialize(Serializer.MSG_RESTART_GAME, {ta: after});
  wss.broadcast(msg);
};

console.log('Server is running on http://'+Config.ip+':'+Config.port);