using System;

using System.Text.RegularExpressions;

using FluentAssertions;

#nullable enable

public class Program

{

    public static void Main()

    {

        Console.WriteLine("----------------------------TEST PAN--------------------------------------------------------");

​

        TestCC("123456789123", "xxxxxxxx9123");

        TestCC("1234-5678-9123-4567", "xxxx-xxxx-xxxx-4567");

        TestCC("123123123123131For8640", "xxxxxxxxxxx3131For8640");

        TestCC("123123123123131to123123123123177", "xxxxxxxxxxx3131toxxxxxxxxxxx3177");

        TestCC("1234-5678-9123-4567-891", "xxxx-xxxx-xxxx-xxx7-891");

        TestCC("1234 5678 9123 4567", "xxxx xxxx xxxx 4567");

        TestCC("1234567", "1234567");

        Console.WriteLine("-----------------------------TEST ACCOUNT NUM-------------------------------------------------------");

        TestAccNo("12345678","xxxx5678");

        TestAccNo("123456789","xxxxx6789");

        TestAccNo("1234567","1234567");

        Console.WriteLine("----------------------------TEST BOTH--------------------------------------------------------");

​

        TestCCAndAccNo("Im paying 2700 dollars with my credit card(123456789012345) to my account(12345678)","Im paying 2700 dollars with my credit card(xxxxxxxxxxx2345) to my account(xxxx5678)");

        TestCC("Im paying 2700 dollars with my credit card(123456789012345) to my account(12345678)","Im paying 2700 dollars with my credit card(xxxxxxxxxxx2345) to my account(12345678)");

​

​

    }

    public static void TestCC(string @value, string expected)

    {

        var result = @value.MaskCCNo();

        result.Should().Be(expected);

        Console.WriteLine($"{@value} => {result}");

    }

    public static void TestAccNo(string @value, string expected)

    {

        var result = @value.MaskAccNo();

        result.Should().Be(expected);

        Console.WriteLine($"{@value} => {result}");

    }

    public static void TestCCAndAccNo(string @value, string expected)

    {

        var result = @value.MaskIfContainCreditCardPanorAcctNumNew();

        result.Should().Be(expected);

        Console.WriteLine($"{@value} => {result}");

    }

}

​

public static class MaskingExtensions

{   

    public static string MaskCCNo(this string value)

  {

      var a = Regex.Replace(value, @"(?<=(?<![\d-|\s])(?=(?:-?\d|\s){12,19}(?![\d-|\s]))[\d-|\s]*)\d(?!(?:-?\d|\s){0,3}(?![\d-|\s]))", "x");

      return a;

  }

    public static string MaskAccNo(this string value)

  {

      var a = Regex.Replace(value, @"(?<=(?<![\d-|\s])(?=(?:-?\d|\s){8,9}(?![\d-|\s]))[\d-|\s]*)\d(?!(?:-?\d|\s){0,3}(?![\d-|\s]))", "x");

      return a;

  }

    public static string MaskIfContainCreditCardPanorAcctNumNew(this string value)

{

    if (string.IsNullOrEmpty(value))

        return value;

​

    var maskedAccountNumber = value.MaskAccNo();

​

    return maskedAccountNumber.MaskCCNo();

}

}