Phone number beautifier

beautify.php

function format_phone($phone) {
  $prefix = null;

  //Check if number has international prefix
  switch(true){
    case substr($phone, 0, 1) == '+':
      $phone = substr($phone, 1);
      $prefix = '+';
      break;
    case substr($phone, 0, 2) == '00':
      $phone = substr($phone, 2);
      $prefix = '+';
      break;
  }

  //Strip all non numeric characters
  $phone = preg_replace("/[^0-9]/", '', $phone);

  switch(strlen($phone)){
    case 6:
      return preg_replace("/([0-9]{2})([0-9]{2})([0-9]{2})/", "$1-$2-$3", $phone);
      break;
    case 7:
      return preg_replace("/([0-9]{3})([0-9]{4})/", "$1-$2", $phone);
      break;
    case 10:
      return preg_replace("/([0-9]{3})([0-9]{3})([0-9]{4})/", "($1) $2-$3", $phone);
      break;
    case 11:
      return preg_replace("/([0-9]{3})([0-9]{4})([0-9]{4})/", $prefix . " ($1) $2-$3", $phone);
      break;
    case 12:
      return preg_replace("/([0-9]{4})([0-9]{4})([0-9]{4})/", $prefix . " ($1) $2-$3", $phone);
      break;
    default:
      return $phone;
      break;
  }
}