public CreditCardDetector(String cardNumber)
{
if (!ValidationHelper.IsAValidNumber(cardNumber))
throw new ArgumentException("Invalid number. Just numbers and white spaces are accepted on the string.");
_cardNumber = cardNumber.RemoveWhiteSpace();
LoadCard();
}
/// <summary>
/// Verify if the card number is valid.
/// </summary>
/// <param name="creditCardNumber"></param>
/// <returns></returns>
public static bool CheckLuhn(String creditCardNumber)
{
if (!ValidationHelper.IsAValidNumber(creditCardNumber))
throw new ArgumentException("Invalid number. Just numbers and white spaces are accepted on the string.");
var checkSum = creditCardNumber
.RemoveWhiteSpace()
.Select(charToInt)
.Reverse()
.Select((digit, index) => isEven(index + 1) ? doubleDigit(digit) : digit)
.Sum();
return checkSum % 10 == 0;
}
public static String CreateCheckDigit(String number)
{
if (!ValidationHelper.IsAValidNumber(number))
throw new ArgumentException("Invalid number. Just numbers and white spaces are accepted on the string.");
var digitsSum = number
.RemoveWhiteSpace()
.Reverse()
.Select(charToInt)
.Select((digit, index) => isEven(index) ? doubleDigit(digit) : digit)
.Sum();
digitsSum = digitsSum * 9;
return digitsSum.ToString().Last().ToString();
}
public static bool IsAValidNumber(String number)
{
number = number.RemoveWhiteSpace();
return (number.All(Char.IsNumber) && !String.IsNullOrEmpty(number));
}
