public RetailOrderDetail AddItem(IProduct product, decimal qty)
{
RetailOrderItem item = Items.FirstOrDefault(x => x.Product.Guid == product.Guid);
if (item == null)
{
item = new RetailOrderItem(product);
Items = Items.Union(new[] { item }).ToArray();
}
item.Quantity += qty;
return(this);
}
public RetailOrderDetail RemoveItem(IProduct product, decimal qty)
{
RetailOrderItem item = Items.FirstOrDefault(x => x.Product.Guid == product.Guid);
if (item != null)
{
item.Quantity -= qty;
if (item.Quantity < 1)
{
Items = Items.Where(x => x.Quantity > 0).ToArray();
}
}
return(this);
}