Tidy a phone number and make it into a formatted 'tel' link

formatted-phone-link.php

/**
* Formatted Phone Link
*/
function format_phone_link($phone) {
  $phone = preg_replace('/[^0-9]/', '', $phone);
  $length = strlen($phone);
  switch ($length) {
    case 7:
    $phone_formatted = preg_replace('/([0-9]{3})([0-9]{4})/', '$1 $2', $phone);
    break;
    case 10:
    $phone_formatted = preg_replace('/([0-9]{3})([0-9]{3})([0-9]{4})/', '$1 $2 $3', $phone);
    break;
    case 11:
    $phone_formatted = preg_replace('/([0-9]{4})([0-9]{3})([0-9]{4})/', '$1 $2 $3', $phone);
    break;
  }
  return '<a href="tel:' . $phone .'">' . $phone_formatted . '</a>';
}