[JS] Wzorzec Mediator

console.clear();
var cl = function(text){ console.log(text); }

var Participant = function(name){
	this.name = name;
	this.chatroom = null;
};

Participant.prototype = {
	send: function(message, to) {
		this.chatroom.send(message, this, to);
	},
	receive: function(message, from) {
		log.add(from.name + ' to ' + this.name + ': ' + message);
	}
};

var log = (function(){
	var log = "";

	return {
		add: function(msg) {
			log += msg + "\n";
		},
		show: function() {
			console.log(log);
			log = "";
		}
	};
})();

var ChatroomMediator = function() {
	var participants = {};

	return {
		register: function(participant) {
			participants[participant.name] = participant;
			participant.chatroom = this;
		},
		send: function(message, from, to) {
			if (to) {
				to.receive(message, from);
			} else {
				var key;
				for (key in participants) {
					if (participants[key] !== from) {
						participants[key].receive(message, from);
					}
				}
			}
		}
	};
};


(function run(){
	var yoko = new Participant('Yoko');
	var john = new Participant('John');
	var paul = new Participant('Paul');


	var chatroom = new ChatroomMediator();
	chatroom.register(yoko);
	chatroom.register(john);
	chatroom.register(paul);

	yoko.send('all you need is love');
	yoko.send('I love you John');
	john.send("Hey, no need to broadcast", yoko);
	paul.send("Ha, I heard that!");

	log.show();
})();