<?php

/*

 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between

 * Copyright (C) 2006-2009 Dan Fuhry

 * render.php - handles fetching pages and parsing them into HTML

 *

 * 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.

 */

class RenderMan {

  public static function strToPageID($string)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    $k = array_keys($paths->nslist);

    $proj_alt = 'Project:';

    if ( substr($string, 0, (strlen($proj_alt))) == $proj_alt )

    {

      $ns = 'Project';

      $pg = substr($string, strlen($proj_alt), strlen($string));

      return Array($pg, $ns);

    }

    for($i=0;$i<sizeof($paths->nslist);$i++)

    {

      $ln = strlen($paths->nslist[$k[$i]]);

      if(substr($string, 0, $ln) == $paths->nslist[$k[$i]])

      {

        $ns = $k[$i];

        $pg = substr($string, strlen($paths->nslist[$ns]), strlen($string));

      }

    }

    return Array($pg, $ns);

  }

  public static function getPage($page_id, $namespace, $wiki = 1, $smilies = true, $filter_links = true, $redir = true, $render = true)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    $page = new PageProcessor($page_id, $namespace);

    $text = $page->fetch_text();

    if ( !$render )

      return $text;

    $text = self::render($text, $wiki, $smilies, $filter_links);

    return $text;

  }

  public static function getTemplate($id, $parms)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    if ( !isPage($paths->get_pathskey($id, 'Template')) ) 

    {

      return '[['.$paths->nslist['Template'].$id.']]';

    }

    if(isset($paths->template_cache[$id]))

    {

      $text = $paths->template_cache[$id];

    }

    else

    {

      $page = new PageProcessor($id, 'Template');

      $text = $page->fetch_text();

      $paths->template_cache[$id] = $text;

    }

    $text = preg_replace('/<noinclude>(.*?)<\/noinclude>/is', '', $text);

    $text = preg_replace('/<nodisplay>(.*?)<\/nodisplay>/is', '\\1', $text);

    preg_match_all('#\(_([0-9]+)_\)#', $text, $matchlist);

    foreach($matchlist[1] as $m)

    {

      if(isset($parms[((int)$m)+1])) 

      {

        $p = $parms[((int)$m)+1];

      }

      else

      {

        $p = '<b>Notice:</b> RenderMan::getTemplate(): Parameter '.$m.' is not set';

      }

      $text = str_replace('(_'.$m.'_)', $p, $text);

      $text = str_replace('{{' . ( $m + 1 ) . '}}', $p, $text);

    }

    $text = RenderMan::include_templates($text);

    return $text;

  }

  public static function fetch_template_text($id)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    $fetch_ns = 'Template';

    if ( !isPage($paths->get_pathskey($id, 'Template')) ) 

    {

      // Transclusion of another page

      // 1.1.5: Now You, Too, Can Be A Template, Even If You're Just A Plain Old Article! (TM)

      $nssep = substr($paths->nslist['Special'], -1);

      $nslist = $paths->nslist;

      foreach ( $nslist as &$ns )

      {

        if ( $ns == '' )

          $ns = $nssep;

      }

      $prefixlist = array_flip($nslist);

      foreach ( $nslist as &$ns )

      {

        $ns = preg_quote($ns);

      }

      $nslist = implode('|', $nslist);

      if ( preg_match("/^($nslist)(.*?)$/", $id, $match) )

      {

        // in practice this should always be true but just to be safe...

        if ( isset($prefixlist[$match[1]]) )

        {

          $new_id = $paths->nslist[ $prefixlist[$match[1]] ] . sanitize_page_id($match[2]);

          if ( !isPage($new_id) )

          {

            return "[[$new_id]]";

          }

          $fetch_ns = $prefixlist[$match[1]];

          $id = sanitize_page_id($match[2]);

        }

      }

      else

      {

        return '[['.$paths->nslist['Template'].$id.']]';

      }

    }

    if(isset($paths->template_cache[$id]))

    {

      $text = $paths->template_cache[$id];

    }

    else

    {

      $text = RenderMan::getPage($id, $fetch_ns, 0, false, false, false, false);

      $paths->template_cache[$id] = $text;

    }

    if ( is_string($text) )

    {

      $text = preg_replace('/<noinclude>(.*?)<\/noinclude>/is', '', $text);

      $text = preg_replace('/<nodisplay>(.*?)<\/nodisplay>/is', '\\1', $text);

    }

    return $text;

  }

  /**

   * Renders a glob of text. Note that this is PHP-safe, so if returned text (or rather, "?>" . $returned) has PHP it can be eval'ed.

   * @param string Text to render

   * @param int Render parameters - see constants.php

   * @return string Rendered text

   */

  public static function render($text, $flags = RENDER_WIKI_DEFAULT, $smilies = true)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    if ( !$smilies )

      $flags |= RENDER_NOSMILIES;

    if ( $flags & ~RENDER_NOSMILIES )

    {

      $text = RenderMan::smilieyize($text);

    }

    if ( $flags & RENDER_WIKI_DEFAULT )

    {

      $text = RenderMan::next_gen_wiki_format($text, $flags);

    }

    else if ( $flags & RENDER_WIKI_TEMPLATE )

    {

      $text = $template->tplWikiFormat($text);

    }           

    return $text;

  }

  private static function next_gen_wiki_format($text, $flags = 0)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    global $lang;

    profiler_log("RenderMan: starting wikitext render");

    require_once( ENANO_ROOT . '/includes/wikiformat.php' );

    require_once( ENANO_ROOT . '/includes/wikiengine/TagSanitizer.php' );

    require_once( ENANO_ROOT . '/includes/wikiengine/Tables.php' );

    // this is still needed by parser plugins

    $random_id = md5( time() . mt_rand() );

    // Strip out <nowiki> sections

    self::nowiki_strip($text, $nowiki_stripped);

    // Run early parsing plugins

    $code = $plugins->setHook('render_wikiformat_veryearly');

    foreach ( $code as $cmd )

    {

      eval($cmd);

    }

    // Strip out embedded PHP

    self::php_strip($text, $php_stripped);

    // Convert newlines for the parser

    $text = str_replace("\r\n", "\n", $text);

    // Perform render through the engine

    $carpenter = new Carpenter();

    $carpenter->flags = $flags;

    $carpenter->hook(array(__CLASS__, 'hook_pre'), PO_AFTER, 'lang');

    $carpenter->hook(array(__CLASS__, 'hook_posttemplates'), PO_AFTER, 'templates');

    if ( $flags & RENDER_WIKI_TEMPLATE )

    {

      // FIXME: Where is noinclude/nodisplay being processed in the pipeline? (Seems to be processed, but not here)

    }

    $text = $carpenter->render($text);

    // For plugin compat

    $result =& $text;

    // Post processing hook

    $code = $plugins->setHook('render_wikiformat_post');

    foreach ( $code as $cmd )

    {

      eval($cmd);

    }

    // Add PHP and nowiki back in

    self::nowiki_unstrip($text, $nowiki_stripped);

    self::php_unstrip($text, $php_stripped);

    profiler_log("RenderMan: finished wikitext render");

    return $text;

  }

  public static function hook_pre($text)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    $code = $plugins->setHook('render_wikiformat_pre');

    foreach ( $code as $cmd )

    {

      eval($cmd);

    }

    return $text;

  }

  public static function hook_posttemplates($text)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    $code = $plugins->setHook('render_wikiformat_posttemplates');

    foreach ( $code as $cmd )

    {

      eval($cmd);

    }

    return $text;

  }

  /**

   * Strip out <nowiki> tags (to bypass parsing on them)

   * @access private

   */

  private static function nowiki_strip(&$text, &$stripdata)

  {

    self::tag_strip('nowiki', $text, $stripdata);

  }

  /**

   * Restore stripped <nowiki> tags.

   * @access private

   */

  public static function nowiki_unstrip(&$text, &$stripdata)

  {

    self::tag_unstrip('nowiki', $text, $stripdata);

  }

  /**

   * Strip out an arbitrary HTML tag.

   * @access private

   */

  public static function tag_strip($tag, &$text, &$stripdata)

  {

    $random_id = md5( time() . mt_rand() );

    preg_match_all("#<$tag>(.*?)</$tag>#is", $text, $blocks);

    foreach ( $blocks[0] as $i => $match )

    {

      $text = str_replace($match, "{{$tag}:{$random_id}:{$i}}", $text);

    }

    $stripdata = array(

        'random_id' => $random_id,

        'blocks' => $blocks[1]

      );

  }

  /**

   * Restore stripped <nowiki> tags.

   * @access private

   */

  public static function tag_unstrip($tag, &$text, &$stripdata, $keep = false)

  {

    $random_id = $stripdata['random_id'];

    foreach ( $stripdata['blocks'] as $i => $block )

    {

      $block = $keep ? "<$tag>$block</$tag>" : $block;

      $text = str_replace("{{$tag}:{$random_id}:{$i}}", $block, $text);

    }

    $stripdata = array();

  }

  /**

   * Strip out PHP code (to prevent it from being sent through the parser). Private because it does not do what you think it does. (The method you are looking for is strip_php.)

   * @access private

   */

  private static function php_strip(&$text, &$stripdata)

  {

    $random_id = md5( time() . mt_rand() );

    preg_match_all('#<\?(?:php)?[\s=].+?\?>#is', $text, $blocks);

    foreach ( $blocks[0] as $i => $match )

    {

      $text = str_replace($match, "{PHP:$random_id:$i}", $text);

    }

    $stripdata = array(

        'random_id' => $random_id,

        'blocks' => $blocks[0]

      );

  }

  /**

   * Restore stripped PHP code

   * @access private

   */

  private static function php_unstrip(&$text, &$stripdata)

  {

    $random_id = $stripdata['random_id'];

    foreach ( $stripdata['blocks'] as $i => $block )

    {

      $text = str_replace("{PHP:$random_id:$i}", $block, $text);

    }

    $stripdata = array();

  }

  /**

   * Deprecated.

   */

  public static function wikiFormat($message, $filter_links = true, $do_params = false, $plaintext = false)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    return RenderMan::next_gen_wiki_format($message, $plaintext, $filter_links, $do_params);

  }

  public static function destroy_javascript($message, $_php = false)

  {

    $message = preg_replace('#<(script|object|applet|embed|iframe|frame|form|input|select)(.*?)>#is', '&lt;\\1\\2&gt;', $message);

    $message = preg_replace('#</(script|object|applet|embed|iframe|frame|form|input|select)(.*?)>#is', '&lt;/\\1\\2&gt;', $message);

    $message = preg_replace('#(javascript|script|activex|chrome|about|applet):#is', '\\1:', $message);

    if ( $_php )

    {

      // Left in only for compatibility

      $message = preg_replace('#&lt;(.*?)>#is', '<\\1>', $message);

      $message = preg_replace('#<(.*?)&gt;#is', '<\\1>', $message);

      $message = preg_replace('#<(\?|\?php|%)(.*?)(\?|%)>#is', '&lt;\\1\\2\\3&gt;', $message);

      // strip <a href="foo" onclick="bar();">-type attacks

      $message = preg_replace('#<([a-zA-Z:\-]+) (.*?)on([A-Za-z]*)=(.*?)>#is', '&lt;\\1\\2on\\3=\\4&gt;', $message);

    }

    return $message;

  }

  public static function strip_php($message)

  {

    return RenderMan::destroy_javascript($message, true);

  }

  public static function sanitize_html($text)

  {

    $text = htmlspecialchars($text);

    $allowed_tags = Array('b', 'i', 'u', 'pre', 'code', 'tt', 'br', 'p', 'nowiki', '!--([\w\W]+)--');

    foreach($allowed_tags as $t)

    {

      $text = preg_replace('#&lt;'.$t.'&gt;(.*?)&lt;/'.$t.'&gt;#is', '<'.$t.'>\\1</'.$t.'>', $text);

      $text = preg_replace('#&lt;'.$t.' /&gt;#is', '<'.$t.' />', $text);

      $text = preg_replace('#&lt;'.$t.'&gt;#is', '<'.$t.'>', $text);

    }

    return $text;

  }

  /**

   * Reverse-renders a blob of text (converts it from XHTML back to wikitext) by using parser hints and educated guesses.

   * @param string XHTML

   * @return string Wikitext

   */

  public static function reverse_render($text)

  {

    // convert \r\n to \n

    $text = str_replace("\r\n", "\n", $text);

    // Separate certain block level elements onto their own lines. This tidies up the tag

    // soup that TinyMCE sometimes produces.

    $block_elements = array('h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'p', 'div', 'table', 'ul', 'pre');

    $block_elements = implode('|', $block_elements);

    $regex = "#(</(?:$block_elements)>)\n?<($block_elements)(>| .+?>)#i";

    $text = preg_replace($regex, "$1\n\n<$2$3", $text);

    $text = self::reverse_process_parser_hints($text);

    $text = self::reverse_process_headings($text);

    $text = self::reverse_process_lists($text);

    $text = self::reverse_process_tables($text);

    // Lastly, strip out paragraph tags.

    $text = preg_replace('|^ *<p>(.+?)</p> *$|m', "\\1", $text);

    return $text;

  }

  public static function reverse_process_parser_hints($text)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    if ( !preg_match_all('|<!--#([a-z0-9_]+)(?: (.+?))?-->([\w\W]*?)<!--#/\\1-->|s', $text, $matches) )

      return $text;

    foreach ( $matches[0] as $i => $match )

    {

      $tag =& $matches[1][$i];

      $attribs =& $matches[2][$i];

      $inner =& $matches[3][$i];

      $attribs = self::reverse_process_hint_attribs($attribs);

      switch($tag)

      {

        case 'smiley':

        case 'internallink':

        case 'imagelink':

          if ( isset($attribs['code']) )

          {

            $text = str_replace($match, $attribs['code'], $text);

          }

          else if ( isset($attribs['src']) )

          {

            $text = str_replace($match, $attribs['src'], $text);

          }

          break;

      }

    }

    return $text;

  }

  public static function reverse_process_hint_attribs($attribs)

  {

    $return = array();

    if ( !preg_match_all('/([a-z0-9_-]+)="([^"]+?)"/', $attribs, $matches) )

      return array();

    foreach ( $matches[0] as $i => $match )

    {

      $name =& $matches[1][$i];

      $value =& $matches[2][$i];

      $value = base64_decode($value);

      $return[$name] = $value;

    }

    return $return;

  }

  /**

   * Escapes a string so that it's safe to use as an attribute in a parser hint.

   * @param string

   * @return string

   */