public void TestBasketSubtractFromTotalLessThanZero()
{
BasketItemModel basketItemApple = new BasketItemModel(_apple);
BasketModel basket = new BasketModel();
basket.AddOrUpdateBasket(basketItemApple);
basket.AddOrUpdateBasket(basketItemApple);
Assert.AreEqual(2, basket.Total);
basket.SubtractFromTotal(3);
Assert.AreEqual(0, basket.Total);
}
/// <summary>
/// Takes a basket of items and a list of promotions and sees if any apply.
/// If they apply it will add it to the item and subtract it from the total basket price.
/// This only allows one Promotion per Item.
/// </summary>
/// <param name="basket"></param>
/// <param name="promotions"></param>
public void ApplyPromotionsToBasket(BasketModel basket, List <PromotionModel> promotions)
{
foreach (var basketItem in basket.Basket)
{
var promotion = promotions.FirstOrDefault(p => p.ItemId == basketItem.ItemId);
if (promotion == null)
{
continue;
}
var discount = new DiscountModel(promotion, basketItem.ItemPrice);
decimal discountAmount = ApplyDiscountToBasketItems(basketItem, discount);
basket.SubtractFromTotal(discountAmount);
}
}