<?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.
 */

class Carpenter_Parse_MediaWiki
{
  public $rules = array(
    'bold'   => "/'''(.+?)'''/",
    'italic' => "/''(.+?)''/",
    'underline' => '/__(.+?)__/',
    'externalwithtext' => '#\[((?:https?|irc|ftp)://.+?) (.+?)\]#',
    'externalnotext' => '#\[((?:https?|irc|ftp)://.+?)\]#',
    'mailtonotext' => '#\[mailto:([^ \]]+?)\]#',
    'mailtowithtext' => '#\[mailto:([^ \]]+?) (.+?)\]#',
    'hr' => '/^[-]{4,} *$/m',
    'code' => '/^<code>(?:\r?\n)?(.+?)(?:\r?\n)?<\/code>$/mis'
  );
  
  private $blockquote_rand_id;
  
  public function lang(&$text)
  {
    global $lang;
    
    preg_match_all('/<lang (?:code|id)="([a-z0-9_-]+)">([\w\W]+?)<\/lang>/', $text, $langmatch);
    foreach ( $langmatch[0] as $i => $match )
    {
      if ( $langmatch[1][$i] == $lang->lang_code )
      {
        $text = str_replace_once($match, $langmatch[2][$i], $text);
      }
      else
      {
        $text = str_replace_once($match, '', $text);
      }
    }
    
    return array();
  }
  
  public function templates(&$text)
  {
    $template_regex = "/\{\{(.+)((\n|\|[ ]*([A-z0-9]+)[ ]*=[ ]*(.+))*)\}\}/isU";
    $i = 0;
    while ( preg_match($template_regex, $text, $match) )
    {
      $i++;
      if ( $i == 5 )
        break;
      $text = RenderMan::include_templates($text);
    }
    
    return array();
  }
  
  public function heading(&$text)
  {
    if ( !preg_match_all('/^(={1,6}) *(.+?) *\\1 *$/m', $text, $results) )
      return array();
    
    $headings = array();
    foreach ( $results[0] as $i => $match )
    {
      $headings[] = array(
          'level' => strlen($results[1][$i]),
          'text' => $results[2][$i]
        );
    }
    
    $text = Carpenter::tokenize($text, $results[0]);
    
    return $headings;
  }
  
  public function multilist(&$text)
  {
    // Match entire lists
    $regex = '/^
                ([:#\*])+     # Initial list delimiter
                [ ]*
                .+?
                (?:
                  \r?\n
                  (?:\\1|[ ]{2,})
                  [ ]*
                  .+?)*
                $/mx';
    
    if ( !preg_match_all($regex, $text, $lists) )
      return array();
    
    $types = array(
        '*' => 'unordered',
        '#' => 'ordered',
        ':' => 'indent'
      );
    
    $pieces = array();
    foreach ( $lists[0] as $i => $list )
    {
      $token = $lists[1][$i];
      $piece = array(
          'type' => $types[$token],
          'items' => array()
        );
      
      // convert windows newlines to unix
      $list = str_replace("\r\n", "\n", $list);
      $items_pre = explode("\n", $list);
      $items = array();
      // first pass, go through and combine items that are newlined
      foreach ( $items_pre as $item )
      {
        if ( substr($item, 0, 1) == $token )
        {
          $items[] = $item;
        }
        else
        {
          // it's a continuation of the previous LI. Don't need to worry about
          // undefined indices here since the regex should filter out all invalid
          // markup. Just append this line to the previous.
          $items[ count($items) - 1 ] .= "\n" . trim($item);
        }
      }
      
      // second pass, separate items and tokens
      unset($items_pre);
      foreach ( $items as $item )
      {
        // get the depth
        $itemtoken = preg_replace('/^([#:\*]+).*$/s', '$1', $item);
        // get the text
        $itemtext = trim(substr($item, strlen($itemtoken)));
        $piece['items'][] = array(
            // depth starts at 1
            'depth' => strlen($itemtoken),
            'text' => $itemtext
          );
      }
      $pieces[] = $piece;
    }
    
    $text = Carpenter::tokenize($text, $lists[0]);
    
    return $pieces;
  }
  
  public function blockquote(&$text)
  {
    $rand_id = hexencode(AESCrypt::randkey(16), '', '');
    
    while ( preg_match_all('/^(?:(>+) *.+(?:\r?\n|$))+/m', $text, $quotes) )
    {
      foreach ( $quotes[0] as $quote )
      {
        $piece = trim(preg_replace('/^> */m', '', $quote));
        $text = str_replace_once($quote, "{blockquote:$rand_id}\n$piece\n{/blockquote:$rand_id}\n", $text);
      }
    }
    //die('<pre>' . htmlspecialchars($text) . '</pre>');
    
    $this->blockquote_rand_id = $rand_id;
  }
  
  public function blockquotepost(&$text)
  {
    return $this->blockquote_rand_id;
  }
  
  public function paragraph(&$text)
  {
    // The trick with paragraphs is to not turn things into them when a block level element already wraps the block of text.
    // First we need a list of block level elements (http://htmlhelp.com/reference/html40/block.html + some Enano extensions)
    $blocklevel = 'address|blockquote|center|code|div|dl|fieldset|form|h1|h2|h3|h4|h5|h6|hr|li|ol|p|pre|table|ul|tr|td|th|tbody|thead|tfoot';
    
    // Wrap all block level tags
    RenderMan::tag_strip('_paragraph_bypass', $text, $_nw);
    
    // I'm not sure why I had to go through all these alternatives. Trying to bring it
    // all down to one by ?'ing subpatterns was causing things to return empty and throwing
    // errors in the parser. Eventually, around ~3:57AM I just settled on this motherf---er
    // of a regular expression.
    
    // FIXME: This regexp triggers a known PHP stack size issue under win32 and possibly
    // other platforms (<http://bugs.php.net/bug.php?id=47689>). The workaround is going to
    // involve writing our own parser that takes care of recursion without using the stack,
    // which is going to be a bitch, and may not make it in until Caoineag RCs.
    
    $regex = ";
              <($blocklevel)
              (?:
                # self closing, no attributes
                [ ]*/>
              |
                # self closing, attributes
                [ ][^>]+? />
              |
                # with inner text, no attributes
                >
                (?: (?R) | .*? )*</\\1>
              |
                # with inner text and attributes
                [ ][^>]+?     # attributes
                >
                (?: (?R) | .*? )*</\\1>
              )
                ;sx";
                
    // oh. and we're using this tokens thing because for identical matches, the first match will
    // get wrapped X number of times instead of all matches getting wrapped once; replacing each
    // with a unique token id remedies this
    
    $tokens = array();
    $rand_id = sha1(microtime() . mt_rand());
    
    // Temporary hack to fix crashes under win32. Sometime I'll write a loop based
    // parser for this whole section. Maybe. Perhaps the Apache folks will fix their
    // Windows binaries first.
    if ( PHP_OS == 'WIN32' || PHP_OS == 'WINNT' )
    {
      $regex = str_replace("(?: (?R) | .*? )*", "(?: .*? )", $regex);
    }
    if ( preg_match_all($regex, $text, $matches) )
    {
      foreach ( $matches[0] as $i => $match )
      {
        $text = str_replace_once($match, "{_pb_:$rand_id:$i}", $text);
        $tokens[$i] = '<_paragraph_bypass>' . $match . '</_paragraph_bypass>';
      }
    }
    
    foreach ( $tokens as $i => $match )
    {
      $text = str_replace_once("{_pb_:$rand_id:$i}", $match, $text);
    }
    
    // die('<pre>' . htmlspecialchars($text) . '</pre>');
	
    RenderMan::tag_unstrip('_paragraph_bypass', $text, $_nw, true);
    
    // This is potentially a hack. It allows the parser to stick in <_paragraph_bypass> tags
    // to prevent the paragraph parser from interfering with pretty HTML generated elsewhere.
    RenderMan::tag_strip('_paragraph_bypass', $text, $_nw);
    
    $startcond = "(?!(?:[\\r\\n]|\{_paragraph_bypass:[a-f0-9]{32}:[0-9]+\}|[ ]*<\/?(?:$blocklevel)(?: .+>|>)))";
    $regex = "/^
                $startcond        # line start condition - do not match if the line starts with the condition above
                .+?               # body text
                (?:
                  \\n             # additional lines
                  $startcond      # make sure of only one newline in a row, and end the paragraph if a new line fails the start condition
                  .*?
                )*                # keep going until it fails
              $
              /mx";
    
    if ( !preg_match_all($regex, $text, $matches) )
    {
      RenderMan::tag_unstrip('_paragraph_bypass', $text, $_nw);
      return array();
    }
    
    // Debugging :)
    // die('<pre>' . htmlspecialchars($text) . "\n-----------------------------------------------------------\n" . htmlspecialchars(print_r($matches, true)) . '</pre>');
    
    // restore stripped
    RenderMan::tag_unstrip('_paragraph_bypass', $text, $_nw);
    
    // tokenize
    $text = Carpenter::tokenize($text, $matches[0]);
    
    return $matches[0];
  }
}

function parser_mediawiki_xhtml_image($text)
{
  $text = RenderMan::process_image_tags($text, $taglist);
  $text = RenderMan::process_imgtags_stage2($text, $taglist);
  return $text;
}

function parser_mediawiki_xhtml_tables($text)
{
  return process_tables($text);
}