<?php

  function getSubclassesOf($parent) {
    $result = array();
    foreach (get_declared_classes() as $class) {
        if (is_subclass_of($class, $parent))
            $result[] = $class;
    }
    return $result;
  }

  function getProtocol() {
    return stripos($_SERVER['SERVER_PROTOCOL'],'https') === 0 ? 'https' : 'http';
  }

  function generateRandomString($length) : string {
    $randomString = '';
    if($length > 0) {
      $numCharacters = 26 + 26 + 10; // a-z + A-Z + 0-9
      for ($i = 0; $i < $length; $i++)
      {
        try {
          $num = random_int(0, $numCharacters - 1);
        } catch (Exception $e) {
          $num = rand(0, $numCharacters - 1);
        }

        if($num < 26) $randomString .= chr(ord('a') + $num);
        else if($num - 26 < 26) $randomString .= chr(ord('A') + $num - 26);
        else $randomString .= chr(ord('0') + $num - 26 - 26);
      }
    }

    return $randomString;
  }

  function startsWith($haystack, $needle) {
   $length = strlen($needle);
   return (substr($haystack, 0, $length) === $needle);
  }

  function endsWith($haystack, $needle) {
    $length = strlen($needle);
    if ($length == 0)
        return true;

    return (substr($haystack, -$length) === $needle);
  }

  function intendCode($code, $escape=true) {
    $newCode = "";
    $first = true;
    $brackets = array();
    $intend = 0;

    foreach(explode("\n", $code) as $line) {
      if(!$first) $newCode .= "\n";
      if($escape) $line = htmlspecialchars($line);
      $line = trim($line);

      if(count($brackets) > 0 && startsWith($line, current($brackets))) {
        $intend = max(0, $intend - 2);
        array_pop($brackets);
      }

      $newCode .= str_repeat(" ", $intend);
      $newCode .= $line;
      $first = false;

      if(endsWith($line, "{")) {
        $intend += 2;
        array_push($brackets, "}");
      } else if(endsWith($line, "(")) {
        $intend += 2;
        array_push($brackets, ")");
      }
    }

    return $newCode;
  }

  function replaceCssSelector($sel) {
    return preg_replace("~[.#<>]~", "_", preg_replace("~[:\-]~", "", $sel));
  }

  function getClassPath($class, $suffix=true) {
    $path = str_replace('\\', '/', $class);
    $suffix = ($suffix ? ".class" : "");
    return "core/$path$suffix.php";
  }

  function createError($msg) {
    return json_encode(array("success" => false, "msg" => $msg));
  }