/**
  * valid module package by zip
  * @param $file
  * @return bool
  */
 static function check_module_zipfile($file)
 {
     $dirs = HW_Unzipper::get_root_dirs_fromzip($file);
     $files = HW_Unzipper::get_root_files_fromzip($file);
     if (!count($dirs) || count($dirs) > 1 || count($files)) {
         return false;
     }
     return !in_array($dirs[0], array_values(HW_File_Directory::list_folders(HW_HOANGWEB_PLUGINS)));
 }