<?php
/*
 * Excerpts - Simply add pages excerpts in your pages.
 *
 * @version 0.2.1
 * @author Wojciech "yojoe" Jodła
 * @link http://jodla.ayz.pl
 * @author Nicolas "p01" Liautaud
 * @link http://nliautaud.fr
 * @author Denis "Wakh" Sharov
 * @link http://webdev.wakh.ru/
 */

# register plugin
$thisfile=basename(__FILE__, ".php");
register_plugin(
    $thisfile,      # ID of plugin, should be filename minus php
    'Excerpts 2',       # Title of plugin
    '0.3',      # Version of plugin
    'yojoe + p01 + Wakh',   # Author of plugin
    'http://jodla.ayz.pl',  # Author URL
    'Simply add pages excerpts in your pages.', # Page type of plugin
    ''      # Function that displays content
);

add_filter('content','parse_tags');

/* Parse a string and replace tags by pages excerpts
 * @param string $contents the string to parse
 * @return string the modified string
 */
function parse_tags($contents)
{
  $pattern = '`(?<!<code>)\(%\s*excerpt\s*:\s*([^, ]*)\s*';
  $pattern.= '(?:,\s*([0-9]*)\s*)?'; // chars number
  $pattern.= '(?:,\s*([0-9]*)\s*)?'; // chars number
  $pattern.= '(?:,\s*(text|html)\s*)'; // text or html
  $pattern.= '(?:,\s*(link|nolink)\s*)'; // readmore
  $pattern.= '?%\)`';
  return preg_replace_callback($pattern, 'callback_to_excerpt', $contents);
}

/* Call page_excerpt from expreg with good parameters.
 * @param string $mask the pattern result
 * @return string the page excerpt
 */
function callback_to_excerpt($mask)
{
  $mask['2'] = isset($mask['2']) ? $mask['2'] : 0;
  $mask['3'] = isset($mask['3']) ? $mask['3'] : 200;
  $mask['4'] = isset($mask['4']) ? $mask['4'] : 'text';
  $mask['5'] = isset($mask['5']) ? $mask['5'] : 'link';
  return page_excerpt($mask['1'], $mask['2'], $mask['3'], $mask['4'], $mask['5']);
}

/* Return the excerpt of a defined page.
 * @param string $name the page name
 * @param int $chars the excerpt length (200 by default)
 * @param string $type output type : text or html (text by default)
 * @return string the excerpt
 */
function page_excerpt($name, $offset = 0, $chars = 200, $type = 'text', $link = 'link')
{
  $file_url = GSDATAPAGESPATH . $name . '.xml';
  if(file_exists($file_url))
  {
    $file = file_get_contents($file_url);
    $page = simplexml_load_string($file);
    $page_len = strlen($page->content);
    $excerpt = $page->content;

    if($type == 'text') {
      $excerpt = htmlspecialchars_decode($excerpt);
      $excerpt = trim(strip_html_tags($excerpt));
    } else {
      $excerpt = html_entity_decode($excerpt);
    }
    $excerpt = mb_substr($excerpt, $offset, $chars, 'UTF-8');
    if($page_len > $chars) {
        if($link == 'link') {
      $excerpt .= '... <a class="read-more" href="' . $name . '/">Подробнее</a>';
            }
    }
    return '<p>' . $excerpt . '</p>';
  }
  return '<p>Plugin error: target page not found.</p>';
}


/* Strip html tags and remove invisible html tags content.
 *
 * PHP's strip_tags() function will remove tags, but it
 * doesn't remove scripts, styles, and other unwanted
 * invisible text between tags.  Also, as a prelude to
 * tokenizing the text, we need to insure that when
 * block-level tags (such as <p> or <div>) are removed,
 * neighboring words aren't joined.
*/
function strip_html_tags($text)
{
  $text = preg_replace(
    array(
      // Remove invisible content
      '@<head[^>]*?>.*?</head>@siu',
      '@<style[^>]*?>.*?</style>@siu',
      '@<script[^>]*?.*?</script>@siu',
      '@<object[^>]*?.*?</object>@siu',
      '@<embed[^>]*?.*?</embed>@siu',
      '@<applet[^>]*?.*?</applet>@siu',
      '@<noframes[^>]*?.*?</noframes>@siu',
      '@<noscript[^>]*?.*?</noscript>@siu',
      '@<noembed[^>]*?.*?</noembed>@siu',

      // Add line breaks before & after blocks
      '@<((br)|(hr))@iu',
      '@</?((address)|(blockquote)|(center)|(del))@iu',
      '@</?((div)|(h[1-9])|(ins)|(isindex)|(p)|(pre))@iu',
      '@</?((dir)|(dl)|(dt)|(dd)|(li)|(menu)|(ol)|(ul))@iu',
      '@</?((table)|(th)|(td)|(caption))@iu',
      '@</?((form)|(button)|(fieldset)|(legend)|(input))@iu',
      '@</?((label)|(select)|(optgroup)|(option)|(textarea))@iu',
      '@</?((frameset)|(frame)|(iframe))@iu',
    ),
    array(
      ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
      "\n\$0", "\n\$0", "\n\$0", "\n\$0", "\n\$0", "\n\$0",
      "\n\$0", "\n\$0",
    ),
    $text);

  // Remove all remaining tags and comments and return.
  return strip_tags($text);
}
?>