/// <summary>
/// Verifies that the CurrentStore can fulfill the product request and then adds it to the Cart.
/// </summary>
/// <param name="productId"></param>
/// <param name="quantity"></param>
public void AddProductToCart(int productId, int quantity)
{
List <Product> availableProducts = CurrentStore.GetAvailableProducts();
if (productId > availableProducts.Count || productId < 0)
{
throw new Exception("Invalid product id");
}
Product product = availableProducts[productId];
OrderDetails cartItem;
if (!_cart.Exists(item => item.Product.ProductId == product.ProductId))
{
cartItem = new OrderDetails
{
Product = product,
Quantity = quantity
};
_cart.Add(cartItem);
}
else
{
cartItem = _cart.Find(item => item.Product.ProductId == product.ProductId);
cartItem.Quantity += quantity;
}
if (!CurrentStore.CanFulfillProductQty(cartItem))
{
cartItem.Quantity -= quantity;
if (cartItem.Quantity == 0)
{
_cart.Remove(cartItem);
}
throw new Exception($"Inventory cannot fulfill quantity: {product.Name} x {quantity}");
}
}