private void CalculateTotal()
{
if (Promotions.Any())
{
Total = 0;
var itemUsedForPromotions = new List <string>();
foreach (var promo in Promotions)
{
if (promo.Type == PromotionType.PriceForQuantityPromotion)
{
var promoType = (PriceForQuantityPromotion)promo;
var item = promoType.Item;
var cartItem = Items.FirstOrDefault(x => x.Item.SKU == item.SKU);
if (cartItem == null)
{
continue;
}
var totalQuantity = Items.Where(x => x.Item.SKU == item.SKU).Sum(x => x.Quantity);
var qualifiedQty = totalQuantity % promoType.Quantity;
Total = qualifiedQty * promoType.Total + (totalQuantity - (qualifiedQty * promoType.Quantity)) * cartItem.Item.Price;
itemUsedForPromotions.Add(cartItem.Item.SKU);
}
}
//Add another promotion type here.
var nonUsedItems = Items.Where(x => !itemUsedForPromotions.Contains(x.Item.SKU));
foreach (var nonUsedItem in nonUsedItems)
{
Total += nonUsedItem.Item.Price * nonUsedItem.Quantity;
}
}
else
{
Total = Items.Sum(x => x.Item.Price * x.Quantity);
}
}
