(function () {
	function Promise(resolver) {
		var
		self = this,
		then = self.then = function () {
			return Promise.prototype.then.apply(self, arguments);
		};

		then.fulfilled = [];
		then.rejected = [];

		function timeout(state, object) {
			then.state = 'pending';

			if (then[state].length) setTimeout(function () {
				timeout(state, then.value = then[state].shift().call(self, object));
			}, 0);
			else then.state = state;
		}

		then.fulfill = function (object) {
			timeout('fulfilled', object);
		};

		then.reject = function (object) {
			timeout('rejected', object);
		};

		resolver.call(self, then.fulfill, then.reject);

		return self;
	}

	Promise.prototype = {
		'constructor': Promise,
		'then': function (onFulfilled, onRejected) {
			if (onFulfilled) this.then.fulfilled.push(onFulfilled);
			if (onRejected) this.then.rejected.push(onRejected);

			if (this.then.state === 'fulfilled') this.then.fulfill(this.then.value);

			return this;
		},
		'catch': function (onRejected) {
			if (onRejected) this.then.rejected.push(onRejected);

			return this;
		}
	};

	Promise.all = function () {
		var
		args = Array.prototype.slice.call(arguments),
		countdown = args.length;

		function process(promise, fulfill, reject) {
			promise.then(function onfulfilled(value) {
				if (promise.then.fulfilled.length > 1) promise.then(onfulfilled);
				else if (!--countdown) fulfill(value);

				return value;
			}, function (value) {
				reject(value);
			});
		}

		return new Promise(function (fulfill, reject) {
			while (args.length) process(args.shift(), fulfill, reject);
		});
	};

	window.Promise = Promise;
})();