public string Generate()
{
var peselStringBuilder = new StringBuilder();
DateTime birthDate = GenerateDate(1900, 2099);
AppendPeselDate(birthDate, peselStringBuilder);
peselStringBuilder.Append(GenerateRandomNumbers(4));
peselStringBuilder.Append(PeselCheckSumCalculator.Calculate(peselStringBuilder.ToString()));
return(peselStringBuilder.ToString());
}
public static bool IsValid(string pesel)
{
var regex = new Regex("^\\d{11}$");
if (!regex.IsMatch(pesel))
{
return(false);
}
int checkSum = PeselCheckSumCalculator.Calculate(pesel);
int lastDigit = pesel.Last() - '0';
return(lastDigit == checkSum);
}