private static CheckoutResult ValidateMasterCard(int number)
{
if (number.ToString().EndsWith('9'))
{
return(CheckoutResult.StaticFailure);
}
return(CheckoutResult.Success("MasterCard"));
}
private static CheckoutResult CheckoutWithCheck(decimal amount, Check check)
{
if (check.Number.ToString().EndsWith('7'))
{
return(CheckoutResult.StaticFailure);
}
return(CheckoutResult.Success("check for " + amount.ToString("#.00") + "$"));
}
private static CheckoutResult ValidateVisa(int number)
{
if (number.ToString().EndsWith('3'))
{
return(CheckoutResult.StaticFailure);
}
return(CheckoutResult.Success("Visa"));
}
private static CheckoutResult CheckoutWithCard(decimal amount, Card card)
{
var result = card.Type.Match(
visa => ValidateVisa(card.Number),
masterCard => ValidateMasterCard(card.Number));
CheckoutResult checkoutWithValidCard(CheckoutSuccess success)
=> CheckoutResult.Success("with " + success.Message + " for " + amount.ToString("#.00") + "$");
return(result.Match(() => CheckoutResult.StaticFailure, succ => checkoutWithValidCard(succ)));
}
private static CheckoutResult CheckoutWithCash(decimal amount)
=> CheckoutResult.Success("cash for " + amount.ToString("#.00") + "$");