public decimal Total(bool applyDiscounts = true)
{
decimal totalPrice = 0.0m;
var productGroups = _products.GroupBy(x => x.SKU);
foreach (var scannedGroup in productGroups)
{
var groupCount = scannedGroup.Count();
var product = scannedGroup.FirstOrDefault();
PricingRule discount = null;
if (applyDiscounts)
{
discount = _discountRules.FirstOrDefault(x => x.SKU == scannedGroup.Key);
}
if (discount != null && groupCount >= discount.Quantity)
{
totalPrice += GetDiscountedPrice(groupCount, product, discount);
}
else
{
totalPrice += product.UnitPrice * groupCount;
}
}
return(totalPrice);
}
private decimal GetDiscountedPrice(int count, Item product, PricingRule discount)
{
return((count / discount.Quantity * discount.DiscountPrice) +
(count % discount.Quantity * product.UnitPrice));
}