public void Charge(Money price, DiscountProgram discountProgram)
{
if (price == null)
{
throw new ArgumentNullException(nameof(price));
}
if (discountProgram == null)
{
throw new ArgumentNullException(nameof(discountProgram));
}
var toCredit = discountProgram
.GetBestDiscount(DiscountCard)
.ApplyOn(price);
Account = Account.Credit(toCredit);
DiscountCard = DiscountCard.RegisterPurchase(price);
}
public User(DiscountCard discountCard, Account account)
{
DiscountCard = discountCard ?? throw new ArgumentNullException(nameof(discountCard));
Account = account ?? throw new ArgumentNullException(nameof(account));
}
