function ShoppingBasket() {
    this.subscribers = [];
    var basket = this;
    this.addProduct = function (productId, quantity, data) {

        $.post('/ECommerce/AddProductToBasket', { productId: productId, quantity: quantity, additionalData: $.toJSON(data) },
            function (message) {
                if (message) {
                    alert(message);
                }

                basket.updateBasket();
            });
    }

    this.updateQuantity = function (productId, quantity, callback) {
        $.post("/ECommerce/UpdateBasketAndCalculateProductPrice",
            {
                productId: productId,
                quantity: quantity
            }, function (data) {
                basket.totalPrice = data.TotalPriceString;
                basket.quantity = quantity;
                //basket.notify();

                if (callback) {
                    callback(data.UnitPriceString, data.TotalPriceString);
                }

                basket.updateBasket();

                //$(".basket-totals").load("/ECommerce/RenderBasketTotals");
            });
    }

    this.updateBasket = function () {
        $(".shopping-basket").load("/ECommerce/RenderBasketItems");
        this.notify();
    }

    this.showConfirmation = function () {
        alert("this item has now been added to your basket");
    }

    this.removeProduct = function (productId) {
        $.post("/ECommerce/RemoveProductFromBasket",
            {
                productId: productId
            }, function () {
                basket.notify();
                $(".shopping-basket").load("/ECommerce/RenderBasketItems", function () {
                });
            });
    }

    this.subscribe = function (subscriber) {
        this.subscribers.push(subscriber);
    }

    this.notify = function () {
        for (var i = 0; i < this.subscribers.length; i++) {
            this.subscribers[i].update();
        }
    }
};

ShoppingBasket.Singleton(new ShoppingBasket);