<?
class Data
{

  public static function type($data, $type, $clean = false)
  {

    if ($clean) {
      // removes words that contain sql syntax
      $data = preg_replace("/(select|update|insert|delete|where|drop table|drop|show tables|mgi|\*|--|\\\\)/", "", $data);
      $data = trim($data);
      $data = strip_tags($data);
      $data = addslashes($data);
    }

    if (is_array($type)) {
      foreach ($type as $k => $v) {
        if ($data == $v) return $data;
      }

      return null;
    } else {

      switch ($type) {
        case "char":
          $data = preg_replace("/[^A-Za-z0-9@._-]+/", "", $data);
          break;
        case "slug":
          $data = preg_replace("/[^\w\ก-๏\-]+/", "", $data);
          break;
        case "number":
          $data = preg_replace("/[^0-9]+/", "", $data);
          break;
        case "date":
          if (!preg_match("/^\d{4}[\-](0?[1-9]|1[012])[\-](0?[1-9]|[12][0-9]|3[01])$/", $data)) {
            $data = '';
          }
          break;
        case "dateslash":
          $d = str_replace("/", "-", $data);
          if (preg_match("/^\d{4}[\-](0?[1-9]|1[012])[\-](0?[1-9]|[12][0-9]|3[01])$/", $d)) {
            $data = '';
          } else {
            $data = str_replace("-", "/", $d);
          }
          break;
        case "datetime":

          if (strlen($data) > 16) {
            if (!preg_match("/^\d{4}[\-](0?[1-9]|1[012])[\-](0?[1-9]|[12][0-9]|3[01])[ *](\d{2}):(\d{2}):(\d{2})$/", $data)) {
              $data = '';
            }
          } else {
            if (!preg_match("/^\d{4}[\-](0?[1-9]|1[012])[\-](0?[1-9]|[12][0-9]|3[01])[ *](\d{2}):(\d{2})$/", $data)) {
              $data = '';
            }
          }

          break;
        case "lang":
          if (in_array($data, array("th", "en", "cn"))) {
            $data = $data;
          } else {
            $data = 'en';
          }
          break;
        case "email":
          $data = preg_replace("/[^a-zA-Z0-9@._-]+/", "", $data);
          $data = strtolower($data);
          break;
        case "url":

          $data = preg_replace("/[^a-zA-Z0-9@._\-\:\/?]+/", "", $data);
          break;
        case "token":

          $data = preg_replace("/[^a-zA-Z0-9@._\-\:]+/", "", $data);

          break;
        case "string":
          $data = strip_tags($data);
          $data = htmlspecialchars($data, ENT_QUOTES);
          break;
      }
    }

    return $data;
  }

  public static function  clean_string($sql)
  {
    // removes words that contain sql syntax
    $sql = preg_replace("/(select|update|insert|delete|where|drop table|drop|show tables|mgi|\*|--|\\\\)/", "", $sql);
    $sql = trim($sql); // strip whitespace
    //$sql = strip_tags($sql); // strip HTML and PHP tags
    $sql = addslashes($sql); // quote string with slashes
    return $sql;
  }

  public static function slug($title, $separator = '-')
  {
    $string = preg_replace('/[^a-z0-9ก-๙เแ]/i', $separator, $title);
    $string = preg_replace('/-+/', $separator, $string);
    $string = preg_replace('/-$|^-/', '', $string);
    return strtolower($string);
  }

  public static function  NormalStr($string)
  {
    $string = html_entity_decode($string);
    $string = strip_tags($string);
    $string = str_replace("&#039;", "'", $string);
    return $string;
  }

  public static function encrypt($text, $time = 0)
  {
    $plaintext = $text;

    if ($time != 0) {
      // $plaintext = $plaintext . '&' . (time() + $time);
    }

    $ivlen = openssl_cipher_iv_length($cipher = "AES-128-CBC");
    $iv = openssl_random_pseudo_bytes($ivlen);
    $ciphertext_raw = openssl_encrypt($plaintext, $cipher, $key, $options = OPENSSL_RAW_DATA, $iv);
    $hmac = hash_hmac('sha256', $ciphertext_raw, $key, $as_binary = true);
    $ciphertext = base64_encode($iv . $hmac . $ciphertext_raw);

    return $ciphertext;
  }

  public static function decrypt($ciphertext)
  {

    $ciphertext = str_replace(" ", "+", $ciphertext);

    $c = base64_decode($ciphertext);
    $ivlen = openssl_cipher_iv_length($cipher = "AES-128-CBC");
    $iv = substr($c, 0, $ivlen);
    $hmac = substr($c, $ivlen, $sha2len = 32);
    $ciphertext_raw = substr($c, $ivlen + $sha2len);
    $original_plaintext = openssl_decrypt($ciphertext_raw, $cipher, $key, $options = OPENSSL_RAW_DATA, $iv);
    $calcmac = hash_hmac('sha256', $ciphertext_raw, $key, $as_binary = true);

    if (hash_equals($hmac, $calcmac)) // timing attack safe comparison
    {
      //$time = end(explode('&', $original_plaintext));

      // if (intval($time) > 0) {
      //   if ($time < time()) {
      //     return "expire";
      //   }
      // }

      // $text = substr($original_plaintext, 0, (strlen($time) + 1) * -1);
      $text = $original_plaintext;
      return $text;
    }
  }
}