private void ApplyPromotionForItemsCombination(IPromotionRule promotion, IItemList items)
{
var discountCombinationItems = promotion.GetItemCombinationList();
var shoppingCartClone = items.GetItemList();
var itemsMarkedForDiscount = new List <KartItem>();
var eligibleForDiscount = false;
foreach (var itemsCountsCombination in discountCombinationItems)
{
var shoppedItem = items.GetItemList()
.Where(ci => ci.ItemObj == itemsCountsCombination.Key)
.Select(ci => ci)
.Single();
if (shoppedItem.Equals(new KeyValuePair <Item, int>()))
{
eligibleForDiscount = false;
break;
}
if (shoppedItem.ItemQuantity >= itemsCountsCombination.Value)
{
eligibleForDiscount = true;
itemsMarkedForDiscount.Add(new KartItem(shoppedItem.ItemObj, shoppedItem.ItemQuantity));
var prod = shoppedItem.ItemObj;
shoppingCartClone.Remove(shoppedItem);
var remainingCount = shoppedItem.ItemQuantity % itemsCountsCombination.Value;
shoppingCartClone.Add(new KartItem(prod, remainingCount));
}
}
if (eligibleForDiscount)
{
int[] arr = new int[itemsMarkedForDiscount.Count];
int i = 0;
// We need to iterate through the collection to get the multipler for promotional KartItem
foreach (var it in itemsMarkedForDiscount)
{
arr[i] = it.ItemQuantity;
i++;
}
int multiplier = arr.Min();
//Once we get the correct multipler, we need to correct Quantity in original Kart, so that correct amount can be calculated.
foreach (var it in itemsMarkedForDiscount)
{
var shoppedItem = items.GetItemList()
.Where(ci => ci.ItemObj == it.ItemObj)
.Select(ci => ci)
.Single();
shoppedItem.ItemQuantity += it.ItemQuantity - multiplier;
shoppedItem.AmountPayable = shoppedItem.ItemQuantity * shoppedItem.ItemObj.ItemPrice;
}
//Here we are adding new KartItem for promotion items.
double amount = promotion.PromotionAmount * multiplier;
Item itm = new Item();
itm.ItemName = promotion.PromotionName;
itm.ItemPrice = promotion.PromotionAmount;
KartItem ktm = new KartItem(itm, multiplier);
items.AddKartItem(ktm);
}
else //reverse and restore
{
itemsMarkedForDiscount.ForEach(it =>
{
shoppingCartClone.Remove(shoppingCartClone.Find(p => p.ItemObj == it.ItemObj));
shoppingCartClone.Add(it);
});
}
}