ajax.php
author Dan
Thu, 17 Dec 2009 04:27:50 -0500
changeset 1168 277a9cdead3e
parent 1162 daa091452877
child 1175 1e2c9819ede3
permissions -rw-r--r--
Namespace_Default: added a workaround for an inconsistency in SQL. Basically, if you join the same table multiple times under multiple aliases, COUNT() always uses the first instance. Was affecting the comment counter in the "discussion" button.

<?php

/*
 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between
 * Copyright (C) 2006-2009 Dan Fuhry
 *
 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
 */
 
  define('ENANO_INTERFACE_AJAX', '');
 
  require('includes/common.php');
  
  global $db, $session, $paths, $template, $plugins; // Common objects
  if(!isset($_GET['_mode'])) die('This script cannot be accessed directly.');
  
  $_ob = '';
  
  switch($_GET['_mode']) {
    case "checkusername":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::checkusername($_GET['name']);
      break;
    case "getsource":
      header('Content-type: text/plain');
      $password = ( isset($_GET['pagepass']) ) ? $_GET['pagepass'] : false;
      $revid = ( isset($_GET['revid']) ) ? intval($_GET['revid']) : 0;
      $page = new PageProcessor($paths->page_id, $paths->namespace, $revid);
      $page->password = $password;
      
      $have_draft = false;
      // Kinda hacky fix for issue 7: draft restore not offered for nonexistent pages
      if ( ($src = $page->fetch_source()) || !$page->exists() )
      {
        $allowed = true;
        $q = $db->sql_query('SELECT author, time_id, page_text, edit_summary, page_format FROM ' . table_prefix . 'logs WHERE log_type = \'page\' AND action = \'edit\'
                               AND page_id = \'' . $db->escape($paths->page_id) . '\'
                               AND namespace = \'' . $db->escape($paths->namespace) . '\'
                               AND is_draft = 1;');
        if ( !$q )
          $db->die_json();
        
        if ( $db->numrows() > 0 )
        {
          $have_draft = true;
          $draft_row = $db->fetchrow($q);
        }
      }
      else if ( $src !== false )
      {
        $allowed = true;
        $src = '';
      }
      else
      {
        $allowed = false;
        $src = '';
      }
      
      $auth_edit = ( $session->get_permissions('edit_page') && ( $session->get_permissions('even_when_protected') || !$page->ns->page_protected ) );
      $auth_wysiwyg = ( $session->get_permissions('edit_wysiwyg') );
      
      $return = array(
          'mode' => 'editor',
          'src' => $src,
          'auth_view_source' => $allowed,
          'auth_edit' => $auth_edit,
          'time' => time(),
          'require_captcha' => false,
          'allow_wysiwyg' => $auth_wysiwyg,
          'revid' => $revid,
          'have_draft' => false
        );
      
      $return['page_format'] = $page->ns->cdata['page_format'];
      if ( $return['page_format'] == 'xhtml' )
      {
        // gently process headings to make tinymce format them correctly
        if ( preg_match_all('/^ *?(={1,6}) *(.+?) *\\1 *$/m', $return['src'], $matches) )
        {
          foreach ( $matches[0] as $i => $match )
          {
            $hi = strlen($matches[1][$i]);
            $heading = "<h{$hi}>{$matches[2][$i]}</h{$hi}>";
            $return['src'] = str_replace_once($match, $heading, $return['src']);
          }
        }
      }
      
      if ( $have_draft )
      {
        $row =& $draft_row;
        $return['have_draft'] = true;
        $return['draft_author'] = $row['author'];
        $return['draft_time'] = enano_date(ED_DATE | ED_TIME, intval($row['time_id']));
        if ( isset($_GET['get_draft']) && @$_GET['get_draft'] === '1' )
        {
          $return['src'] = $row['page_text'];
          $return['edit_summary'] = $row['edit_summary'];
          $return['page_format'] = $row['page_format'];
        }
      }
      
      $return['undo_info'] = array();
      
      if ( $revid > 0 )
      {
        // Retrieve information about this revision and the current one
        $q = $db->sql_query('SELECT l1.author AS currentrev_author, l2.author AS oldrev_author FROM ' . table_prefix . 'logs AS l1
  LEFT JOIN ' . table_prefix . 'logs AS l2
    ON ( l2.log_id = ' . $revid . '
         AND l2.log_type  = \'page\'
         AND l2.action    = \'edit\'
         AND l2.page_id   = \'' . $db->escape($paths->page_id)   . '\'
         AND l2.namespace = \'' . $db->escape($paths->namespace) . '\'
         AND l2.is_draft != 1
        )
  WHERE l1.log_type  = \'page\'
    AND l1.action    = \'edit\'
    AND l1.page_id   = \'' . $db->escape($paths->page_id)   . '\'
    AND l1.namespace = \'' . $db->escape($paths->namespace) . '\'
    AND l1.time_id   > ' . $page->revision_time . '
    AND l1.is_draft != 1
  ORDER BY l1.time_id DESC;');
        if ( !$q )
          $db->die_json();
        
        if ( $db->numrows() > 0 )
        {
          $rev_count = $db->numrows() - 1;
          if ( $rev_count == -1 )
          {
            $return = array(
                'mode' => 'error',
                'error' => '[Internal] No rows returned by revision info query. SQL:<pre>' . $db->latest_query . '</pre>'
              );
          }
          else
          {
            $row = $db->fetchrow();
            $return['undo_info'] = array(
              'old_author'     => $row['oldrev_author'],
              'current_author' => $row['currentrev_author'],
              'undo_count'     => $rev_count
            );
          }
        }
        else
        {
          $return['revid'] = $revid = 0;
        }
      }
      
      if ( $auth_edit && !$session->user_logged_in && getConfig('guest_edit_require_captcha') == '1' )
      {
        $return['require_captcha'] = true;
        $return['captcha_id'] = $session->make_captcha();
      }
      
      $template->load_theme();
      $return['toolbar_templates'] = $template->extract_vars('toolbar.tpl');
      $return['edit_notice'] = $template->get_wiki_edit_notice();
      
      echo enano_json_encode($return);
      break;
    case "getpage":
      // echo PageUtils::getpage($paths->page, false, ( (isset($_GET['oldid'])) ? $_GET['oldid'] : false ));
      $output = new Output_Striptease();
      
      $revision_id = ( (isset($_GET['oldid'])) ? intval($_GET['oldid']) : 0 );
      $page = new PageProcessor( $paths->page_id, $paths->namespace, $revision_id );
      
      $pagepass = ( isset($_REQUEST['pagepass']) ) ? $_REQUEST['pagepass'] : '';
      $page->password = $pagepass;
      $page->allow_redir = ( !isset($_GET['redirect']) || (isset($_GET['redirect']) && $_GET['redirect'] !== 'no') );
            
      $page->send();
      break;
    case "savepage":
      /* **** OBSOLETE **** */
      
      break;
    case "savepage_json":
      header('Content-type: application/json');
      if ( !isset($_POST['r']) )
        die('Invalid request');
      
      try
      {
        $request = enano_json_decode($_POST['r']);
        if ( !isset($request['src']) || !isset($request['summary']) || !isset($request['minor_edit']) || !isset($request['time']) || !isset($request['draft']) )
          die('Invalid request');
      }
      catch(Zend_Json_Exception $e)
      {
        die("JSON parsing failed. View as HTML to see full report.\n<br /><br />\n<pre>" . htmlspecialchars(strval($e)) . "</pre><br />Request: <pre>" . htmlspecialchars($_POST['r']) . "</pre>");
      }
      
      $time = intval($request['time']);
      
      if ( $request['draft'] )
      {
        //
        // The user wants to save a draft version of the page.
        //
        
        // Validate permissions
        if ( !$session->get_permissions('edit_page') )
        {
          $return = array(
            'mode' => 'error',
            'error' => 'access_denied'
          );
        }
        else
        {
          // Delete any draft copies if they exist
          $q = $db->sql_query('DELETE FROM ' . table_prefix . 'logs WHERE log_type = \'page\' AND action = \'edit\'
                                 AND page_id = \'' . $db->escape($paths->page_id) . '\'
                                 AND namespace = \'' . $db->escape($paths->namespace) . '\'
                                 AND is_draft = 1;');
          if ( !$q )
            $db->die_json();
          
          // are we just supposed to delete the draft?
          if ( $request['src'] === -1 )
          {
            $return = array(
              'mode' => 'success',
              'is_draft' => 'delete'
            );
          }
          else
          {
            $src = RenderMan::preprocess_text($request['src'], false, false);
            $draft_format = $request['format'];
            if ( !in_array($draft_format, array('xhtml', 'wikitext')) )
            {
              $return = array(
                'mode' => 'error',
                'error' => 'invalid_format'
              );
            }
            else
            {
              // Save the draft
              $q = $db->sql_query('INSERT INTO ' . table_prefix . 'logs ( log_type, action, page_id, namespace, author, edit_summary, page_text, is_draft, time_id, page_format )
                                     VALUES (
                                       \'page\',
                                       \'edit\',
                                       \'' . $db->escape($paths->page_id) . '\',
                                       \'' . $db->escape($paths->namespace) . '\',
                                       \'' . $db->escape($session->username) . '\',
                                       \'' . $db->escape($request['summary']) . '\',
                                       \'' . $db->escape($src) . '\',
                                       1,
                                       ' . time() . ',
                                       \'' . $draft_format . '\'
                                     );');
              
              // Done!
              $return = array(
                  'mode' => 'success',
                  'is_draft' => true
                );
            }
          }
        }
      }
      else
      {
        // Verify that no edits have been made since the editor was requested
        $q = $db->sql_query('SELECT time_id, author FROM ' . table_prefix . "logs WHERE log_type = 'page' AND action = 'edit' AND page_id = '{$paths->page_id}' AND namespace = '{$paths->namespace}' AND is_draft != 1 ORDER BY time_id DESC LIMIT 1;");
        if ( !$q )
          $db->die_json();
        
        $row = $db->fetchrow();
        $db->free_result();
        
        if ( $row['time_id'] > $time )
        {
          $return = array(
            'mode' => 'obsolete',
            'author' => $row['author'],
            'date_string' => enano_date(ED_DATE | ED_TIME, $row['time_id']),
            'time' => $row['time_id'] // time() ???
            );
          echo enano_json_encode($return);
          break;
        }
        
        // Verify captcha, if needed
        if ( false && !$session->user_logged_in && getConfig('guest_edit_require_captcha') == '1' )
        {
          if ( !isset($request['captcha_id']) || !isset($request['captcha_code']) )
          {
            die('Invalid request, need captcha metadata');
          }
          $code_correct = strtolower($session->get_captcha($request['captcha_id']));
          $code_input = strtolower($request['captcha_code']);
          if ( $code_correct !== $code_input )
          {
            $return = array(
              'mode' => 'errors',
              'errors' => array($lang->get('editor_err_captcha_wrong')),
              'new_captcha' => $session->make_captcha()
            );
            echo enano_json_encode($return);
            break;
          }
        }
        
        // Verification complete. Start the PageProcessor and let it do the dirty work for us.
        $page = new PageProcessor($paths->page_id, $paths->namespace);
        if ( $page->update_page($request['src'], $request['summary'], ( $request['minor_edit'] == 1 ), $request['format']) )
        {
          $return = array(
              'mode' => 'success',
              'is_draft' => false
            );
        }
        else
        {
          $errors = array();
          while ( $err = $page->pop_error() )
          {
            $errors[] = $err;
          }
          $return = array(
            'mode' => 'errors',
            'errors' => array_values($errors)
            );
          if ( !$session->user_logged_in && getConfig('guest_edit_require_captcha') == '1' )
          {
            $return['new_captcha'] = $session->make_captcha();
          }
        }
      }
      
      // If this is based on a draft version, delete the draft - we no longer need it.
      if ( @$request['used_draft'] && !$request['draft'] )
      {
        $q = $db->sql_query('DELETE FROM ' . table_prefix . 'logs WHERE log_type = \'page\' AND action = \'edit\'
                               AND page_id = \'' . $db->escape($paths->page_id) . '\'
                               AND namespace = \'' . $db->escape($paths->namespace) . '\'
                               AND is_draft = 1;');
      }
      
      echo enano_json_encode($return);
      
      break;
    case "diff_cur":
      
      // Lie about our content type to fool ad scripts
      header('Content-type: application/xhtml+xml');
      
      if ( !isset($_POST['text']) )
        die('Invalid request');
      
      $page = new PageProcessor($paths->page_id, $paths->namespace);
      if ( !($src = $page->fetch_source()) )
      {
        die('Access denied');
      }
      
      $diff = RenderMan::diff($src, $_POST['text']);
      if ( $diff == '<table class="diff"></table>' )
      {
        $diff = '<p>' . $lang->get('editor_msg_diff_empty') . '</p>';
      }
      
      echo '<div class="info-box">' . $lang->get('editor_msg_diff') . '</div>';
      echo $diff;
      
      break;
    case "protect":
      // echo PageUtils::protect($paths->page_id, $paths->namespace, (int)$_POST['level'], $_POST['reason']);
      
      if ( @$_POST['reason'] === '__ROLLBACK__' )
      {
        // __ROLLBACK__ is a keyword for log entries.
        die('"__ROLLBACK__" ain\'t gonna do it, buddy. Try to _not_ use reserved keywords next time, ok?');
      }
      
      $page = new PageProcessor($paths->page_id, $paths->namespace);
      header('Content-type: application/json');
      
      $result = $page->protect_page(intval($_POST['level']), $_POST['reason']);
      echo enano_json_encode($result);
      break;
    case "histlist":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::histlist($paths->page_id, $paths->namespace);
      break;
    case "rollback":
      $id = intval(@$_GET['id']);
      $page = new PageProcessor($paths->page_id, $paths->namespace);
      header('Content-type: application/json');
      
      $result = $page->rollback_log_entry($id);
      echo enano_json_encode($result);
      break;
    case "comments":
      require_once(ENANO_ROOT.'/includes/comment.php');
      $comments = new Comments($paths->page_id, $paths->namespace);
      if ( isset($_POST['data']) )
      {
        $comments->process_json($_POST['data']);
      }
      else
      {
        die('{ "mode" : "error", "error" : "No input" }');
      }
      break;
    case "rename":
      $page = new PageProcessor($paths->page_id, $paths->namespace);
      header('Content-type: application/json');
      
      $result = $page->rename_page($_POST['newtitle']);
      echo enano_json_encode($result);
      break;
    case "flushlogs":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::flushlogs($paths->page_id, $paths->namespace);
      break;
    case "deletepage":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      $reason = ( isset($_POST['reason']) ) ? $_POST['reason'] : false;
      if ( empty($reason) )
        die($lang->get('page_err_need_reason'));
      echo PageUtils::deletepage($paths->page_id, $paths->namespace, $reason);
      break;
    case "delvote":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::delvote($paths->page_id, $paths->namespace);
      break;
    case "resetdelvotes":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::resetdelvotes($paths->page_id, $paths->namespace);
      break;
    case "getstyles":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::getstyles($_GET['id']);
      break;
    case "catedit":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::catedit($paths->page_id, $paths->namespace);
      break;
    case "catsave":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::catsave($paths->page_id, $paths->namespace, $_POST);
      break;
    case "setwikimode":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::setwikimode($paths->page_id, $paths->namespace, (int)$_GET['mode']);
      break;
    case "setpass":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      echo PageUtils::setpass($paths->page_id, $paths->namespace, $_POST['password']);
      break;
    case "fillusername":
      break;
    case "fillpagename":
      break;
    case "preview":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      $template->init_vars();
      echo PageUtils::genPreview($_POST['text']);
      break;
    case "transform":
      header('Content-type: text/javascript');
      if ( !isset($_GET['to']) )
      {
        echo enano_json_encode(array(
            'mode' => 'error',
            'error' => '"to" not specified'
          ));
        break;
      }
      if ( !isset($_POST['text']) )
      {
        echo enano_json_encode(array(
            'mode' => 'error',
            'error' => '"text" not specified (must be on POST)'
          ));
        break;
      }
      switch($_GET['to'])
      {
        case 'xhtml':
          $result = RenderMan::render($_POST['text'], RENDER_BLOCK | RENDER_NOSMILIES, false);
          break;
        case 'wikitext':
          $result = RenderMan::reverse_render($_POST['text']);
          break;
        default:
          $text =& $_POST['text'];
          $result = false;
          $code = $plugins->setHook('ajax_transform');
          foreach ( $code as $cmd )
          {
            eval($cmd);
          }
          if ( !$result )
          {
            echo enano_json_encode(array(
                'mode' => 'error',
                'error' => 'Invalid target format'
              ));
            break;
          }
          break;
      }
      
      // mostly for debugging, but I suppose this could be useful elsewhere.
      if ( isset($_POST['plaintext']) )
        die($result);
      
      echo enano_json_encode(array(
          'mode' => 'transformed_text',
          'text' => $result
        ));
      break;
    case "pagediff":
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      $id1 = ( isset($_GET['diff1']) ) ? (int)$_GET['diff1'] : false;
      $id2 = ( isset($_GET['diff2']) ) ? (int)$_GET['diff2'] : false;
      if(!$id1 || !$id2) { echo '<p>Invalid request.</p>'; $template->footer(); break; }
      if(!preg_match('#^([0-9]+)$#', (string)$_GET['diff1']) ||
         !preg_match('#^([0-9]+)$#', (string)$_GET['diff2']  )) { echo '<p>SQL injection attempt</p>'; $template->footer(); break; }
      echo PageUtils::pagediff($paths->page_id, $paths->namespace, $id1, $id2);
      break;
    case "jsres":
      die('// ERROR: this section is deprecated and has moved to includes/clientside/static/enano-lib-basic.js.');
      break;
    case "rdns":
      if(!$session->get_permissions('mod_misc')) die('Go somewhere else for your reverse DNS info!');
      $ip = $_GET['ip'];
      if ( !is_valid_ip($ip) )
      {
        echo $lang->get('acpsl_err_invalid_ip');
      }
      $rdns = gethostbyaddr($ip);
      if ( $rdns == $ip )
        echo $lang->get('acpsl_err_ptr_no_resolve');
      else echo $rdns;
      break;
    case 'acljson':
      require_once(ENANO_ROOT.'/includes/pageutils.php');
      $parms = ( isset($_POST['acl_params']) ) ? rawurldecode($_POST['acl_params']) : false;
      echo PageUtils::acl_json($parms);
      break;
    case 'theme_list':
      header('Content-type: application/json');
      
      $return = array();
      foreach ( $template->theme_list as $theme )
      {
        if ( $theme['enabled'] != 1 )
          continue;
        
        $return[] = array(
            'theme_name' => $theme['theme_name'],
            'theme_id' => $theme['theme_id'],
            'have_thumb' => file_exists(ENANO_ROOT . "/themes/{$theme['theme_id']}/preview.png")
          );
      }
      
      echo enano_json_encode($return);
      
      break;
    case "get_styles":
      if ( !preg_match('/^[a-z0-9_-]+$/', $_GET['theme_id']) )
        die(enano_json_encode(array()));
      
      $theme_id = $_GET['theme_id'];
      $return = array();
      
      if ( $dr = @opendir(ENANO_ROOT . "/themes/$theme_id/css/") )
      {
        while ( $dh = @readdir($dr) )
        {
          if ( preg_match('/\.css$/', $dh) && $dh != '_printable.css' )
          {
            $return[] = preg_replace('/\.css$/', '', $dh);
          }
        }
      }
      else
      {
        $return = array(
            'mode' => 'error',
            'error' => 'Could not open directory.'
          );
      }
      echo enano_json_encode($return);
      break;
    case "change_theme":
      if ( !isset($_POST['theme_id']) || !isset($_POST['style_id']) )
      {
        die(enano_json_encode(array('mode' => 'error', 'error' => 'Invalid parameter')));
      }
      if ( !preg_match('/^([a-z0-9_-]+)$/i', $_POST['theme_id']) || !preg_match('/^([a-z0-9_-]+)$/i', $_POST['style_id']) )
      {
        die(enano_json_encode(array('mode' => 'error', 'error' => 'Invalid parameter')));
      }
      if ( !file_exists(ENANO_ROOT . '/themes/' . $_POST['theme_id'] . '/css/' . $_POST['style_id'] . '.css') )
      {
        die(enano_json_encode(array('mode' => 'error', 'error' => 'Can\'t find theme file: ' . ENANO_ROOT . '/themes/' . $_POST['theme_id'] . '/css/' . $_POST['style_id'] . '.css')));;
      }
      if ( !$session->user_logged_in )
      {
        die(enano_json_encode(array('mode' => 'error', 'error' => 'You must be logged in to change your theme')));
      }
      // Just in case something slipped through...
      $theme_id = $db->escape($_POST['theme_id']);
      $style_id = $db->escape($_POST['style_id']);
      $e = $db->sql_query('UPDATE ' . table_prefix . "users SET theme = '$theme_id', style = '$style_id' WHERE user_id = $session->user_id;");
      if ( !$e )
        die( $db->get_error() );
      
      echo enano_json_encode(array(
          'success' => true
        ));
      break;
    case 'get_tags':
      
      $ret = array('tags' => array(), 'user_level' => $session->user_level, 'can_add' => $session->get_permissions('tag_create'));
      $q = $db->sql_query('SELECT t.tag_id, t.tag_name, pg.pg_target IS NOT NULL AS used_in_acl, t.user_id FROM '.table_prefix.'tags AS t
        LEFT JOIN '.table_prefix.'page_groups AS pg
          ON ( ( pg.pg_type = ' . PAGE_GRP_TAGGED . ' AND pg.pg_target=t.tag_name ) OR ( pg.pg_type IS NULL AND pg.pg_target IS NULL ) )
        WHERE t.page_id=\'' . $db->escape($paths->page_id) . '\' AND t.namespace=\'' . $db->escape($paths->namespace) . '\';');
      if ( !$q )
        $db->_die();
      
      while ( $row = $db->fetchrow() )
      {
        $can_del = true;
        
        $perm = ( $row['user_id'] != $session->user_id ) ?
                'tag_delete_other' :
                'tag_delete_own';
        
        if ( $row['user_id'] == 1 && !$session->user_logged_in )
          // anonymous user trying to delete tag (hardcode blacklisted)
          $can_del = false;
          
        if ( !$session->get_permissions($perm) )
          $can_del = false;
        
        if ( $row['used_in_acl'] == 1 && !$session->get_permissions('edit_acl') && $session->user_level < USER_LEVEL_ADMIN )
          $can_del = false;
        
        $ret['tags'][] = array(
          'id' => $row['tag_id'],
          'name' => $row['tag_name'],
          'can_del' => $can_del,
          'acl' => ( $row['used_in_acl'] == 1 )
        );
      }
      
      echo enano_json_encode($ret);
      
      break;
    case 'addtag':
      $resp = array(
          'success' => false,
          'error' => 'No error',
          'can_del' => ( $session->get_permissions('tag_delete_own') && $session->user_logged_in ),
          'in_acl' => false
        );
      
      // first of course, are we allowed to tag pages?
      if ( !$session->get_permissions('tag_create') )
      {
        $resp['error'] = 'You are not permitted to tag pages.';
        die(enano_json_encode($resp));
      }
      
      // sanitize the tag name
      $tag = sanitize_tag($_POST['tag']);
      $tag = $db->escape($tag);
      
      if ( strlen($tag) < 2 )
      {
        $resp['error'] = 'Tags must consist of at least 2 alphanumeric characters.';
        die(enano_json_encode($resp));
      }
      
      // check if tag is already on page
      $q = $db->sql_query('SELECT 1 FROM '.table_prefix.'tags WHERE page_id=\'' . $db->escape($paths->page_id) . '\' AND namespace=\'' . $db->escape($paths->namespace) . '\' AND tag_name=\'' . $tag . '\';');
      if ( !$q )
        $db->_die();
      if ( $db->numrows() > 0 )
      {
        $resp['error'] = 'This page already has this tag.';
        die(enano_json_encode($resp));
      }
      $db->free_result();
      
      // tricky: make sure this tag isn't being used in some page group, and thus adding it could affect page access
      $can_edit_acl = ( $session->get_permissions('edit_acl') || $session->user_level >= USER_LEVEL_ADMIN );
      $q = $db->sql_query('SELECT 1 FROM '.table_prefix.'page_groups WHERE pg_type=' . PAGE_GRP_TAGGED . ' AND pg_target=\'' . $tag . '\';');
      if ( !$q )
        $db->_die();
      if ( $db->numrows() > 0 && !$can_edit_acl )
      {
        $resp['error'] = 'This tag is used in an ACL page group, and thus can\'t be added to a page by people without administrator privileges.';
        die(enano_json_encode($resp));
      }
      $resp['in_acl'] = ( $db->numrows() > 0 );
      $db->free_result();
      
      // we're good
      $q = $db->sql_query('INSERT INTO '.table_prefix.'tags(tag_name,page_id,namespace,user_id) VALUES(\'' . $tag . '\', \'' . $db->escape($paths->page_id) . '\', \'' . $db->escape($paths->namespace) . '\', ' . $session->user_id . ');');
      if ( !$q )
        $db->_die();
      
      $resp['success'] = true;
      $resp['tag'] = $tag;
      $resp['tag_id'] = $db->insert_id();
      
      echo enano_json_encode($resp);
      break;
    case 'deltag':
      
      $tag_id = intval($_POST['tag_id']);
      if ( empty($tag_id) )
        die('Invalid tag ID');
      
      $q = $db->sql_query('SELECT t.tag_id, t.user_id, t.page_id, t.namespace, pg.pg_target IS NOT NULL AS used_in_acl FROM '.table_prefix.'tags AS t
  LEFT JOIN '.table_prefix.'page_groups AS pg
    ON ( pg.pg_id IS NULL OR ( pg.pg_target = t.tag_name AND pg.pg_type = ' . PAGE_GRP_TAGGED . ' ) )
  WHERE t.tag_id=' . $tag_id . ';');
      
      if ( !$q )
        $db->_die();
      
      if ( $db->numrows() < 1 )
        die('Could not find a tag with that ID');
      
      $row = $db->fetchrow();
      $db->free_result();
      
      if ( $row['page_id'] == $paths->page_id && $row['namespace'] == $paths->namespace )
        $perms =& $session;
      else
        $perms = $session->fetch_page_acl($row['page_id'], $row['namespace']);
        
      $perm = ( $row['user_id'] != $session->user_id ) ?
                'tag_delete_other' :
                'tag_delete_own';
      
      if ( $row['user_id'] == 1 && !$session->user_logged_in )
        // anonymous user trying to delete tag (hardcode blacklisted)
        die('You are not authorized to delete this tag.');
        
      if ( !$perms->get_permissions($perm) )
        die('You are not authorized to delete this tag.');
      
      if ( $row['used_in_acl'] == 1 && !$perms->get_permissions('edit_acl') && $session->user_level < USER_LEVEL_ADMIN )
        die('You are not authorized to delete this tag.');
      
      // We're good
      $q = $db->sql_query('DELETE FROM '.table_prefix.'tags WHERE tag_id = ' . $tag_id . ';');
      if ( !$q )
        $db->_die();
      
      echo 'success';
      
      break;
    case 'ping':
      echo 'pong';
      break;
    default:
      die('Hacking attempt');
      break;
  }
  
?>