<?php
/**
 *
 * @category        framewotk
 * @package         backend admin
 * @author          Ryan Djurovich, WebsiteBaker Project
 * @copyright       WebsiteBaker Org. e.V.
 * @link            http://websitebaker.org/
 * @license         http://www.gnu.org/licenses/gpl.html
 * @platform        WebsiteBaker 2.8.3
 * @requirements    PHP 5.3.6 and higher
 * @version         $Id: class.admin.php 2 2017-07-02 15:14:29Z Manuela $
 * @filesource      $HeadURL: svn://isteam.dynxs.de/wb/2.10.x/trunk/framework/class.admin.php $
 * @lastmodified    $Date: 2017-07-02 17:14:29 +0200 (Sun, 02 Jul 2017) $
 *
 */
/* -------------------------------------------------------- */
// Must include code to stop this file being accessed directly
if(!defined('WB_PATH')) {
    require_once(dirname(__FILE__).'/globalExceptionHandler.php');
    throw new IllegalFileException();
}
/* -------------------------------------------------------- */
if (!class_exists('wb', false)) {require(WB_PATH.'/framework/class.wb.php');}

// Get WB version
require_once(ADMIN_PATH.'/interface/version.php');

// Include EditArea wrapper functions
// require_once(WB_PATH . '/include/editarea/wb_wrapper_edit_area.php');
//require_once(WB_PATH . '/framework/SecureForm.php');


class admin extends wb {

    private $section_name;
    private $section_permission;

    // Authenticate user then auto print the header
    public function __construct($section_name= '##skip##', $section_permission = 'start', $auto_header = true, $auto_auth = true)
    {
        parent::__construct(1);
    if( $section_name != '##skip##' )
    {
        global $database, $MESSAGE;
        $database = @$GLOBALS['database'];
        // Specify the current applications name
        $this->section_name = $section_name;
        $this->section_permission = $section_permission;
        $maintance = ( defined( 'SYSTEM_LOCKED') && ( SYSTEM_LOCKED == true) ? true : false);
        // Authenticate the user for this application
        if($auto_auth == true)
        {
            // First check if the user is logged-in
            if($this->is_authenticated() == false)
            {
                header('Location: '.ADMIN_URL.'/login/index.php');
                exit(0);
            }

            // Now check if they are allowed in this section
            if($this->get_permission($section_permission) == false) {
                die($MESSAGE['ADMIN_INSUFFICIENT_PRIVELLIGES']);
            }
        }
        if( ( $maintance == true) || $this->get_session( 'USER_ID') != 1) {
          //  check for show maintenance screen and terminate if needed
          $this->ShowMaintainScreen( 'locked');
        }

        // Check if the backend language is also the selected language. If not, send headers again.
        $sql  = 'SELECT `language` FROM `'.TABLE_PREFIX.'users` ';
        $sql .= 'WHERE `user_id`='.(int)$this->get_user_id();
        $user_language = $database->get_one($sql);
        $admin_folder = str_replace(WB_PATH, '', ADMIN_PATH);
        if((LANGUAGE != $user_language) && file_exists(WB_PATH .'/languages/' .$user_language .'.php')
            && strpos($_SERVER['SCRIPT_NAME'],$admin_folder.'/') !== false) {
            // check if page_id is set
            $page_id_url = (isset($_GET['page_id'])) ? '&page_id=' .(int) $_GET['page_id'] : '';
            $section_id_url = (isset($_GET['section_id'])) ? '&section_id=' .(int) $_GET['section_id'] : '';
            $sScriptUrl = $_SERVER['SCRIPT_NAME'];
            if(isset($_SERVER['QUERY_STRING']) && $_SERVER['QUERY_STRING'] != '') { // check if there is an query-string
                header('Location: '.$sScriptUrl.'?lang='.$user_language .$page_id_url .$section_id_url.'&'.$_SERVER['QUERY_STRING']);
            } else {
                header('Location: '.$sScriptUrl.'?lang='.$user_language .$page_id_url .$section_id_url);
            }
            exit();
        }

        // Auto header code
        if($auto_header == true) {
            $this->print_header();
        }
    }
    }

    private function mysqlVersion() {
      global $database;
      $sql = 'SELECT VERSION( ) AS versionsinfo';
      if( $oRes = ($database->query($sql)) ) {
          $aRes = $oRes->fetchRow(MYSQLI_ASSOC);
          return $aRes['versionsinfo'];
      }
      return 0;
    }

    private function mysqlStrict() {
      global $database;
      $retVal ='';
      $sql = 'SELECT @@global.sql_mode AS strictinfo';
      if( $oRes = ($database->query($sql)) ) {
          $aRes = $oRes->fetchRow(MYSQLI_ASSOC);
          $retVal = $aRes['strictinfo'];
      }
      return is_numeric( strpos( $retVal,'STRICT' ) );
    }

    public function print_info (){
        global $MENU, $MESSAGE, $TEXT, $database;
// Create new template object with phplib
        $oTpl = new Template(dirname($this->correct_theme_source('call_help.htt')));
        $oTpl->set_file('page', 'call_help.htt');
        $oTpl->set_block('page', 'main_block', 'main');
        $aLang = array(
            'CANCEL' => $TEXT['CANCEL'],
            'TITLE_INFO' => 'WebsiteBaker System-Info',

        );
        $aTplDefaults = array(
            'ADMIN_URL' => ADMIN_URL.'',
            'INFO_URL' => ADMIN_URL.'/start/wb_info.php',
            'sAddonThemeUrl' => THEME_URL.'',
        );
        $oTpl->set_var($aLang);
        $oTpl->set_var($aTplDefaults);
/*-- finalize the page -----------------------------------------------------------------*/
        $oTpl->parse('main', 'main_block', false);
        $oTpl->pparse('output', 'page');

    }

    // Print the admin header
    public function print_header($body_tags = '') {
        // Get vars from the language file
        global $MENU, $MESSAGE, $TEXT, $database;
        // Connect to database and get website title
        // $GLOBALS['FTAN'] = $this->getFTAN();
//        $this->createFTAN();
        $sql = 'SELECT `value` FROM `'.TABLE_PREFIX.'settings` '
             . 'WHERE `name`=\'website_title\'';
        $get_title = $database->query($sql);
        $aWebsiteTitle= $get_title->fetchRow( MYSQLI_ASSOC );
        // Setup template object, parse vars to it, then parse it
        $header_template = new Template(dirname($this->correct_theme_source('header.htt')));
        $header_template->set_file('page', 'header.htt');
        $header_template->set_block('page', 'header_block', 'header');
        if(defined('DEFAULT_CHARSET')) {
            $charset=DEFAULT_CHARSET;
        } else {
            $charset='utf-8';
        }

        // work out the URL for the 'View menu' link in the WB backend
        // if the page_id is set, show this page otherwise show the root directory of WB
        $view_url = WB_URL;
        $info_url = ($this->get_user_id()==1 ? ADMIN_URL.'/start/info.php':ADMIN_URL);
        if(isset($_GET['page_id'])) {
            // extract page link from the database
            $sql = 'SELECT `link` FROM `'.TABLE_PREFIX.'pages` '
                 . 'WHERE `page_id`='.intval($_GET['page_id']);
            $result = @$database->query($sql);
            $row = @$result->fetchRow( MYSQLI_ASSOC );
            if($row) $view_url .= PAGES_DIRECTORY .$row['link']. PAGE_EXTENSION;
        }


        $convertToReadableSize = function ($size){
          $base = log($size) / log(1024);
          $suffix = array("", " KB", " MB", " GB", " TB");
          $f_base = floor($base);
          return round(pow(1024, $base - floor($base)), 1) . $suffix[$f_base];
        };

        $sIconPost = '0';
        $aFileStat = array();
        $sErrorlogFile = WB_PATH.'/var/logs/php_error.log.php';
        $sErrorlogUrl  = WB_URL.'/var/logs/php_error.log.php';
        if (is_readable($sErrorlogFile)){
            clearstatcache($sErrorlogFile);
            $iFileSize = filesize($sErrorlogFile);
            $sIconPost = (($iFileSize>3000)?'1':'0');
        }
        $header_template->set_var('ERROR_SIZE', $convertToReadableSize($iFileSize)); //
//        $header_template->set_var('ERROR_MSG', $sErrorlogMsg); //
        $header_template->set_var('ERROR_LOG', $sErrorlogUrl); // $sErrorlogUrl
        $header_template->set_var('POST',$sIconPost);

        $datalist['Header'] =
                      array(
                            'FTAN_GET' => ( DEBUG ? $this->getFTAN('GET') : '' ),
                            'SECTION_NAME'        => $MENU[strtoupper($this->section_name)],
                            'TEMPLATE_DIR'        => DEFAULT_THEME,
                            'STYLE'               => strtolower($this->section_name),
                            'BODY_TAGS'           => $body_tags,
                            'WEBSITE_TITLE'       => ($aWebsiteTitle['value']),
                            'TEXT_ADMINISTRATION' => $TEXT['ADMINISTRATION'],
                            'CURRENT_USER'        => $MESSAGE['START_CURRENT_USER'],
                            'DISPLAY_NAME'        => $this->get_display_name(),
                            'CHARSET'             => $charset,
                            'LANGUAGE'            => strtolower(LANGUAGE),
                            'WB_URL'              => WB_URL,
                            'ADMIN_URL'           => ADMIN_URL,
                            'THEME_URL'           => THEME_URL,
                            'TEMPLATE'            => defined('TEMPLATE')?TEMPLATE:DEFAULT_TEMPLATE,
                            'EDITOR'              => WYSIWYG_EDITOR,
                            'TITLE_START'         => $MENU['START'],
                            'TITLE_VIEW'          => $MENU['VIEW'],
                            'TITLE_HELP'          => $MENU['HELP'],
                            'TITLE_INFO'          => 'WebsiteBaker System-Info',
                            'TITLE_LOGOUT'        =>  $MENU['LOGOUT'],
                            'URL_VIEW'            => $view_url,
                            'INFO_URL'            => $info_url,
                            'URL_HELP'            => 'http://help.websitebaker.org/',
                            'BACKEND_MODULE_CSS'  => $this->register_backend_modfiles('css'),    // adds backend.css
                            'BACKEND_MODULE_JS'   => $this->register_backend_modfiles('js')      // adds backend.js
                        );

/*------------------------------------------------------------------------------------*/
    $header_template->set_var($datalist['Header'] );
    $header_template->set_block( 'header_block', 'maintenance_block', 'maintenance');
    if( $this->get_user_id() == 1) {

      $sys_locked = ( ( ( int)( defined( 'SYSTEM_LOCKED') ? SYSTEM_LOCKED : 0)) == 1);
      $header_template->set_var( 'MAINTENANCE_MODE', ( $sys_locked ? $this->_oTrans->TEXT_MAINTENANCE_OFF :
        $this->_oTrans->TEXT_MAINTENANCE_ON));
      $header_template->set_var( 'MAINTENANCE_ICON', THEME_URL.'/images/'.( $sys_locked ? 'lock' :
        'unlock').'.png');
      $header_template->set_var( 'MAINTAINANCE_URL', ADMIN_URL.'/settings/locking.php');
      $header_template->parse( 'maintenance', 'maintenance_block', true);
    } else {
      $header_template->set_block( 'maintenance_block', '');
    }
/*------------------------------------------------------------------------------------*/

        // Create the backend menu
        $aMenu = array(
//                    array(ADMIN_URL.'/start/index.php',               '', $MENU['START'],       'start',       1),
                    array(ADMIN_URL.'/pages/index.php',               '', $MENU['PAGES'],       'pages',       1),
                    array(ADMIN_URL.'/media/index.php',               '', $MENU['MEDIA'],       'media',       1),
                    array(ADMIN_URL.'/addons/index.php',              '', $MENU['ADDONS'],      'addons',      1),
                    array(ADMIN_URL.'/preferences/index.php',         '', $MENU['PREFERENCES'], 'preferences', 0),
                    array(ADMIN_URL.'/settings/index.php?advanced=0', '', $MENU['SETTINGS'],    'settings',    1),
                    array(ADMIN_URL.'/admintools/index.php',          '', $MENU['ADMINTOOLS'],  'admintools',  1),
                    array(ADMIN_URL.'/access/index.php',              '', $MENU['ACCESS'],      'access',      1),
                    );
        $header_template->set_block('header_block', 'linkBlock', 'link');
        foreach($aMenu AS $menu_item)
        {
            $link = $menu_item[0];
            $target = ($menu_item[1] == '') ? '_self' : $menu_item[1];
            $titleMenu = $menu_item[2];
            $permission_title = $menu_item[3];
            $required = $menu_item[4];
            $replace_old = array(ADMIN_URL, WB_URL, '/', 'index.php');
            if ($required == false || $this->get_link_permission($permission_title)) {
                $header_template->set_var('LINK', $link);
                $header_template->set_var('TARGET', $target);
                // If link is the current section apply a class name
                if ($permission_title == strtolower($this->section_name)) {
                    $info_url = ($this->get_user_id()==1 ? ADMIN_URL.'/start/info.php?url='.$link:ADMIN_URL);
                    $header_template->set_var('CLASS', $menu_item[3] . ' current');
                } else {
                    $header_template->set_var('CLASS', $menu_item[3]);
                }
                $header_template->set_var('TITLE', $titleMenu);
                // Print link
                $header_template->parse('link', 'linkBlock', true);
                $header_template->set_block('header_block', 'infoBlockBasis',   'infoBasis');
                $header_template->set_block('header_block', 'infoBlockExented', 'infoExented');

                $header_template->set_block('header_block', 'button_info_block', 'button_info');
                $bCanShowInfoBlock = (DEBUG&&$this->ami_group_member('1') || ($this->get_user_id()=='1'));
                if (!$bCanShowInfoBlock){
                    $header_template->set_block('button_info', '');
                } else {
                    $header_template->parse('button_info', 'button_info_block', true);
                }
                if ((strtolower($this->section_name) == 'admintools') && (!$bCanShowInfoBlock))
                {
//                    print ($this->section_name).'<br />';
                    $header_template->set_block('infoBasis', '');
                    $header_template->set_var( array(
                                        'VERSION'             => WB_VERSION,
                                        'SP'                  => (defined('WB_SP') ? WB_SP : ''),
                                        'REVISION'            => WB_REVISION,
                                        'PHP_VERSION'         => phpversion(),
                                        'TEXT_EXT_INFO'       => 'SQL  Server:',
                                        'EXT_INFO'            => $this->mysqlVersion(),
                                        'EXT_INFO1'           => ( ($this->mysqlStrict())?'STRICT': 'NON STRICT' ),
                                    ) );

                    $header_template->parse('infoExented', 'infoBlockExented', true);
                } else {
//                    print '<b>'.$menu_item[3].'/<b><br />';
//                    $header_template->set_block('infoExented', '');
                    $header_template->set_block('infoExented', '');
                    $header_template->set_var( array(
                                        'VERSION'             => VERSION,
                                        'SP'                  => (defined('SP') ? SP : ''),
                                        'REVISION'            => REVISION,
                                        'PHP_VERSION'         => phpversion(),
                                        'SERVER_ADDR'         => ($this->get_user_id() == 1
                                                                   ? (!isset($_SERVER['SERVER_ADDR'])
                                                                      ? '127.0.0.1'
                                                                      : $_SERVER['SERVER_ADDR'])
                                                                  : ''),
                                    ) );
                    $header_template->parse('infoBasis', 'infoBlockBasis', true);
                }
            }
        }

        $header_template->parse('header', 'header_block', false);
        $header_template->pparse('output', 'page');
    }

    // Print the admin footer
        public function print_footer($activateJsAdmin = false) {
        // include the required file for Javascript admin
        if($activateJsAdmin != false) {
            if(file_exists(WB_PATH.'/modules/jsadmin/jsadmin_backend_include.php')){
                @include_once(WB_PATH.'/modules/jsadmin/jsadmin_backend_include.php');
            }
        }

        // Setup template object, parse vars to it, then parse it
        $footer_template = new Template(dirname($this->correct_theme_source('footer.htt')));
        $footer_template->set_file('page', 'footer.htt');
        $footer_template->set_block('page', 'footer_block', 'header');
        $footer_template->set_var(array(
                        'BACKEND_BODY_MODULE_JS' => $this->register_backend_modfiles_body('js'),
                        'WB_URL' => WB_URL,
                        'ADMIN_URL' => ADMIN_URL,
                        'THEME_URL' => THEME_URL,
                        'INFO_URL' =>  ADMIN_URL.'/start/wb_info.php',
             ) );
        $footer_template->parse('header', 'footer_block', false);
        $footer_template->pparse('output', 'page');
    }

    // Return a system permission
    public function get_permission($name, $type = 'system') {
        // Append to permission type
        $type .= '_permissions';
        // Check if we have a section to check for
        if($name == 'start') {
            return true;
        } else {
            // Set system permissions var
            $system_permissions = $this->get_session('SYSTEM_PERMISSIONS');
            // Set module permissions var
            $module_permissions = $this->get_session('MODULE_PERMISSIONS');
            // Set template permissions var
            $template_permissions = $this->get_session('TEMPLATE_PERMISSIONS');
            // Return true if system perm = 1
            if (isset($$type) && is_array($$type) && is_numeric(array_search($name, $$type))) {
                if($type == 'system_permissions') {
                    return true;
                } else {
                    return false;
                }
            } else {
                if($type == 'system_permissions') {
                    return false;
                } else {
                    return true;
                }
            }
        }
    }

 public function get_user_details($user_id) {
  global $database;
  $retval = array('username'=>'unknown','display_name'=>'Unknown','email'=>'');
  $sql  = 'SELECT `username`,`display_name`,`email` ';
  $sql .= 'FROM `'.TABLE_PREFIX.'users` ';
  $sql .= 'WHERE `user_id`='.(int)$user_id;
  if( ($resUsers = $database->query($sql)) ) {
   if( ($recUser = $resUsers->fetchRow(MYSQLI_ASSOC)) ) {
    $retval = $recUser;
   }
  }
  return $retval;
 }

    //
    public function get_section_details( $section_id, $backLink = 'index.php' ) {
    global $database, $TEXT;
        $sql  = 'SELECT * FROM `'.TABLE_PREFIX.'sections` ';
        $sql .= 'WHERE `section_id`='.intval($section_id);
        if(($resSection = $database->query($sql))){
            if(!($recSection = $resSection->fetchRow(MYSQLI_ASSOC))) {
                $this->print_header();
                $this->print_error($TEXT['SECTION'].' '.$TEXT['NOT_FOUND'], $backLink, true);
            }
            } else {
                $this->print_header();
                $this->print_error($database->get_error(), $backLink, true);
            }
        return $recSection;
    }

    public function get_page_details( $page_id, $backLink = 'index.php' ) {
        global $database, $TEXT;
        $sql  = 'SELECT * FROM `'.TABLE_PREFIX.'pages` ';
        $sql .= 'WHERE `page_id`='.intval($page_id);
        if(($resPages = $database->query($sql))){
            if(!($recPage = $resPages->fetchRow(MYSQLI_ASSOC))) {
            $this->print_header();
            $this->print_error($TEXT['PAGE'].' '.$TEXT['NOT_FOUND'], $backLink, true);
            }
        } else {
            $this->print_header();
            $this->print_error($database->get_error(), $backLink, true);
        }
        return $recPage;
    }

    public function get_page_permission($page,$action='admin') {
        if($action != 'viewing') { $action = 'admin'; }
        $action_groups = $action.'_groups';
        $action_users  = $action.'_users';
        $groups = $users = '0';
        if(is_array($page)) {
            $groups = $page[$action_groups];
            $users  = $page[$action_users];
        } else {
            global $database;
            $sql  = 'SELECT `'.$action_groups.'`,`'.$action_users.'` ';
            $sql .= 'FROM `'.TABLE_PREFIX.'pages` ';
            $sql .= 'WHERE `page_id`='.(int)$page;
            if( ($res = $database->query($sql)) ) {
                if( ($rec = $res->fetchRow(MYSQLI_ASSOC)) ) {
                    $groups = $rec[$action_groups];
                    $users  = $rec[$action_users];
                }
            }
        }
        return ($this->ami_group_member($groups) || $this->is_group_match($this->get_user_id(), $users));
    }

    // Returns a system permission for a menu link
    public function get_link_permission($title) {
        $title = str_replace('_blank', '', $title);
        $title = strtolower($title);
        // Set system permissions var
        $system_permissions = $this->get_session('SYSTEM_PERMISSIONS');
        // Set module permissions var
        $module_permissions = $this->get_session('MODULE_PERMISSIONS');
        if($title == 'start') {
            return true;
        } else {
            // Return true if system perm = 1
            if(is_numeric(array_search($title, $system_permissions))) {
                return true;
            } else {
                return false;
            }
        }
    }

    // Function to add optional module Javascript or CSS stylesheets into the <body> section of the backend
    public function register_backend_modfiles_body($file_id="js")
    {
        $sCallingScript = $_SERVER['SCRIPT_NAME'];
        $AcpDir = str_replace('\\','/', ADMIN_PATH).'/';
        if( preg_match( '/'.'pages\/(settings|sections)\.php$/is', $sCallingScript)) {
          return;
        }
        // sanity check of parameter passed to the function
        $file_id = strtolower($file_id);
        if($file_id !== "javascript" && $file_id !== "js")
        {
            return;
        }
        global $database;
        $body_links = "";
        // define default baselink and filename for optional module javascript and stylesheet files
        if($file_id == "js") {
            $base_link = '<script src="'.WB_URL.'/modules/{MODULE_DIRECTORY}/backend_body.js" type="text/javascript"></script>';
            $base_file = "backend_body.js";
        }
        // check if backend_body.js files needs to be included to the <body></body> section of the backend
        if(isset($_GET['tool']))
        {
            // check if displayed page contains a installed admin tool
            $sql  = 'SELECT * FROM `'.TABLE_PREFIX.'addons` ';
            $sql .= 'WHERE `type`=\'module\' AND `function`=\'tool\' AND `directory`=\''.$database->escapeString($_GET['tool']).'\'';
            $result = $database->query($sql);
            if($result->numRows())
            {
                // check if admin tool directory contains a backend_body.js file to include
                $tool = $result->fetchRow(MYSQLI_ASSOC);
                if(file_exists(WB_PATH .'/modules/' .$tool['directory'] .'/'.$base_file))
                {
                    // return link to the backend_body.js file
                    return str_replace('{MODULE_DIRECTORY}', $tool['directory'], $base_link);
                }
            }
        } elseif(isset($_GET['page_id']) || isset($_POST['page_id']))
        {
            // check if displayed page in the backend contains a page module
            if (isset($_GET['page_id']))
            {
                $page_id = (int) $database->escapeString($_GET['page_id']);
            } else {
                $page_id = (int) $database->escapeString($_POST['page_id']);
            }
            // gather information for all models embedded on actual page
            $sql = 'SELECT DISTINCT `module` FROM `'.TABLE_PREFIX.'sections` WHERE `page_id`='.(int)$page_id;
            $query_modules = $database->query($sql);
            while($row = $query_modules->fetchRow(MYSQLI_ASSOC)) {
                // check if page module directory contains a backend_body.js file
                if(file_exists(WB_PATH .'/modules/' .$row['module'] .'/'.$base_file)) {
                    // create link with backend_body.js source for the current module
                    $tmp_link = str_replace("{MODULE_DIRECTORY}", $row['module'], $base_link);
                    // ensure that backend_body.js is only added once per module type
                    if(strpos($body_links, $tmp_link) === false) {
                        $body_links .= $tmp_link ."\n";
                    }
                }
            }
            // write out links with all external module javascript/CSS files, remove last line feed
            return rtrim($body_links);
        }
    }


    // Function to add optional module Javascript or CSS stylesheets into the <head> section of the backend  preg_quote($AcpDir,'/').
    public function register_backend_modfiles($file_id="css") {
        $sCallingScript = $_SERVER['SCRIPT_NAME'];
        $AcpDir = str_replace('\\','/', ADMIN_PATH).'/';
        if( preg_match( '/'.'pages\/(settings|sections)\.php$/is', $sCallingScript)) {
          return;
        }
        // sanity check of parameter passed to the function
        $file_id = strtolower($file_id);
        if($file_id !== "css" && $file_id !== "javascript" && $file_id !== "js") {
            return;
        }

        global $database;
        // define default baselink and filename for optional module javascript and stylesheet files
        $head_links = "";
        if($file_id == "css") {
          $base_link = '<link href="'.WB_URL.'/modules/{MODULE_DIRECTORY}/backend.css"';
            $base_link.= ' rel="stylesheet" type="text/css" media="screen" />';
            $base_file = "backend.css";
        } else {
            $base_link = '<script src="'.WB_URL.'/modules/{MODULE_DIRECTORY}/backend.js" type="text/javascript"></script>';
            $base_file = "backend.js";
        }

        // check if backend.js or backend.css files needs to be included to the <head></head> section of the backend
        if(isset($_GET['tool'])) {
            // check if displayed page contains a installed admin tool
            $sql  = 'SELECT * FROM `'.TABLE_PREFIX.'addons` ';
            $sql .= 'WHERE `type`=\'module\' AND `function`=\'tool\' AND `directory`=\''.$database->escapeString($_GET['tool']).'\'';
            $result = $database->query($sql);
            if($result->numRows()) {
                // check if admin tool directory contains a backend.js or backend.css file to include
                $tool = $result->fetchRow(MYSQLI_ASSOC);
                if(file_exists(WB_PATH .'/modules/' .$tool['directory'] .'/'.$base_file)) {
                    // return link to the backend.js or backend.css file
                    return str_replace("{MODULE_DIRECTORY}", $tool['directory'], $base_link);
                }
            }
        } elseif(isset($_GET['page_id']) || isset($_POST['page_id'])) {
            // check if displayed page in the backend contains a page module
            if (isset($_GET['page_id'])) {
                $page_id = (int)$_GET['page_id'];
            } else {
                $page_id = (int)$_POST['page_id'];
            }
            // gather information for all models embedded on actual page
            $sql = 'SELECT `module` FROM `'.TABLE_PREFIX.'sections` WHERE `page_id`='.(int)$page_id;
            $query_modules = $database->query($sql);
            while($row = $query_modules->fetchRow(MYSQLI_ASSOC)) {
//                if ($row['module']=='wysiwyg') {$row['module']=WYSIWYG_EDITOR;}
                // check if page module directory contains a backend.js or backend.css file
                if(file_exists(WB_PATH .'/modules/' .$row['module'] .'/'.$base_file))
                {
                    // create link with backend.js or backend.css source for the current module
                    $tmp_link = str_replace("{MODULE_DIRECTORY}", $row['module'], $base_link);
                    // ensure that backend.js or backend.css is only added once per module type
                    if(strpos($head_links, $tmp_link) === false) {
                        $head_links .= $tmp_link ."\n";
                    }
                }
            }
            // write out links with all external module javascript/CSS files, remove last line feed
            return rtrim($head_links);
        }
    }
}