private AddProductResult TryUpdate(Variant item, int quantity, ProductBasketItem matchingItem)
{
var newQuantity = matchingItem.Quantity + quantity;
if (newQuantity > MaximumQuantityForItem)
{
return(new AddProductResult.QuantityExceeded(newQuantity - MaximumQuantityForItem));
}
ApplyChange(new ExistingProductUpdatedEvent(Id, matchingItem.ItemId, item, quantity));
return(new AddProductResult.ProductUpdated());
}
public AddProductResult AddVariant(Variant item, int quantity)
{
if (quantity > MaximumQuantityForItem)
{
return(new AddProductResult.QuantityExceeded(quantity - MaximumQuantityForItem));
}
var matchingItem = Items.Cast <ProductBasketItem>()
.FirstOrDefault(x => x.VariantId == item.VariantId);
if (matchingItem != null)
{
return(TryUpdate(item, quantity, matchingItem));
}
RemoveMatchingExpiredItems(item);
ApplyChange(new NewProductAddedEvent(Id, ProductBasketItem.Create(item, quantity)));
return(new AddProductResult.NewProductAdded());
}