Daily Challenge #179 - Hide Phone Numbers

const encryptNum = num => num.replace(/(\d[ .-]?){6}$/, x => x.replace(/\d/g, 'X'))

function encryptNum(num){
  return num.substr(0, 5) + 'XX-XXXX'
}

fn encrypt_num(phone_number: String) -> String {
    let mut bytes = phone_number.into_bytes();
    for ch in bytes.iter_mut().rev().filter(|b| {
        let c = **b as char;
        '0' <= c && c <= '9'
    }).take(6) {
        *ch = 'X' as u8;
    }
    String::from_utf8(bytes).unwrap()
}

fn main() {
    assert_eq!(encrypt_num("328 6587120".to_owned()), "328 6XXXXXX");
    assert_eq!(encrypt_num("212-420-0202".to_owned()), "212-4XX-XXXX");
    assert_eq!(encrypt_num("211-458-7851".to_owned()), "211-4XX-XXXX");
}

import Data.Char (isDigit)

encryptNum :: String -> String
encryptNum = reverse . encryptDigit 0 . reverse
    where
        encryptDigit 6 xs     = xs
        encryptDigit i (x:xs) | isDigit x = 'X' : encryptDigit (i+1) xs
                              | otherwise =  x  : encryptDigit i xs

def encrypt(phone_num):
  # define some const. easy to refactor into method sig or config elsewhere later
  ENCRYPT_NUMBER = 6
  ENCRYPT_SYMBOL = 'X'

  # we'll return this at the end - reversed and joined.
  encrypted = []
  # count the numbers we encrypt
  counter = 0

  # start at the end and encrypt numbers until we reach ENCRYPT_NUMBER
  for ch in phone_num[::-1]:
    # we're done encrypting so pass everything along
    if counter == ENCRYPT_NUMBER:
      encrypted.append(ch)
      continue

    try:
      # if character is a number, encrypt it
      int(ch)
      counter += 1
      encrypted.append(ENCRYPT_SYMBOL)
    except ValueError:
      # character is not a number so pass it  through
      encrypted.append(ch)

  # return a string in the right order
  return ''.join(encrypted[::-1])

print(encrypt("328 6587120")) # 328 6XXXXXX
print(encrypt("212-420-0202")) # 212-4XX-XXXX
print(encrypt("211-458-7851")) # 211-4XX-XXXX
print(encrypt("211 458 7851")) # 211 4XX XXXX
print(encrypt("2114587851")) # 2114XXXXXX

encryptDigit : Char -> Char
encryptDigit character =
    if Char.isDigit character then
        'X'

    else
        character


encryptNum : String -> String
encryptNum string =
    String.map encryptDigit ( String.dropLeft 5 string )
        |> String.append ( String.left 5 string )

def encryptNum(input : String) = {
  def encryptInner(remain : Int, toGo : List[Char]) : List[Char] = {
    toGo match {
      case Nil => Nil
      case _ if remain == 0 => toGo
      case x::xs if x.isDigit => 'X' :: encryptInner(remain - 1, xs)
      case x::xs => x :: encryptInner(remain, xs)
    }
  }

  encryptInner(6, input.reverse.toList).reverse.mkString
}

const encryptNum = num => num.replace(/((\d[-\s.]?){4})(\d)([\s.-]?)(\d)([\s.-]?)(\d)([\s.-]?)(\d)([\s.-]?)(\d)([\s.-]?)(\d)/, '$1X$4X$6X$8X$10X$12X');

String encryptNum(String phoneNum) {
  var regexp = RegExp(r"([0-9- .]+)");
  var result = regexp?.firstMatch(phoneNum)?.group(0);
  result = result?.replaceAll(new RegExp(r"(\.|-|\s)"), "");
  if(result.length == 10) {
    var val = StringBuffer();
    for(var idx = 0; idx < result.length; idx++) {
      if(idx < 4) {
        val.write(result[idx]);
      } else {
        val.write("X");
      }
      switch(idx) {
        case 2:
        case 5:
          val.write("-");
        break;
      }
    }
    return val.toString();
  }
  return null;
}

print(encryptNum("142 424 2142"));
print(encryptNum("142 424-2142"));
print(encryptNum("142 424.2142"));
print(encryptNum("142 4242142"));
print(encryptNum("142-424-2142"));
print(encryptNum("142-424 2142"));
print(encryptNum("142-424.2142"));
print(encryptNum("142-4242142"));
print(encryptNum("142.424 2142"));
print(encryptNum("142.424-2142"));
print(encryptNum("142.424.2142"));
print(encryptNum("142.4242142"));
print(encryptNum("142424-2142"));
print(encryptNum("142424.2142"));
print(encryptNum("142424 2142"));
print(encryptNum("1424242142"));

const encryptNum = (num) => {
  const nums = num.match(/\d/gi).join("");
  return `${nums.substring(0,3)}-${nums.substring(3,6)}-${nums.substring(6)}`;
}

const encryptNum = (num) => {
  let numbers = 0;
  let position = num.length - 1;
  let formattedNum = num.split("");

  while (numbers < 6 && position > 0) {
    if (num[position] >= "0" && num[position] <= "9") { 
      formattedNum[position] = "x";
      numbers++;
    }
    position--;
  }

  return formattedNum.join("");
}