<?php
// $Id: textile.module,v 1.25.2.13 2011-01-19 03:47:14 kiam Exp $

/**
 * @file
 * The textile module allows input of Textile shorthand.
 */

/**
 * Implements hook_filter_info().
 */
function textile_filter_info() {
  $filters['textile'] = array(
    'title' => t('Textile'),
    'description' => t('Allows content to be submitted using Textile, a simple, plain text syntax that is filtered into valid XHTML.'),
    'process callback' => '_textile_process',
    'settings callback' => '_textile_settings',
    'default settings' => array(
      'textile_tags' => FALSE,
    ),
    'tips callback' => '_textile_filter_tips',
  );

  return $filters;
}

/**
 * Implements hook_help().
 */
function textile_help($path, $arg) {
  switch ($path) {
    case 'admin/help#textile':
      return '<p>' . t('
        The Textile module allows users to enter content using Textile, a
        simple, plain text syntax that is filtered into valid XHTML. The <a
        href="filter/tips" title="Textile help">filter tips page</a>
        provides syntax descriptions and examples.') . '</p>';
  }
}

/**
 * Retrivies where the Textile library has been copied.
 *
 * @return
 *   The path of the Textile library.
 */
function textile_library_path() {
  $path = &Vars::staticValue(__FUNCTION__, '');
  $vars = new Vars();

  if ($path) {
    return $path;
  }

  $dirs = $vars->getLibraryPath('textile');
  $dirs[] = drupal_get_path('module', 'textile') . '/include';
  foreach ($dirs as $dir) {
    $bool = (
      is_dir(DRUPAL_ROOT . '/' . $dir) &&
      file_exists(DRUPAL_ROOT . "$dir/classTextile.php") &&
      is_file(DRUPAL_ROOT . "/$dir/classTextile.php")
    );
    if ($bool) {
      $path = $dir;
      break;
    }
  }

  // Allow third-party modules to alter the path where the library is found.
  drupal_alter('textile_library_path', $path);

  return $path;
}

/**
 * Filter tips callback for the Textile filter.
 */
function _textile_filter_tips($filter, $format, $long = FALSE) {
  if ($long) {
    module_load_include('inc', 'textile', 'textile.tips');
    return _textile_filter_long_tips();
  }
  elseif (isset($filter->settings['textile_tags']) && $filter->settings['textile_tags']) {
    return t('You can use Textile markup to format text between the [textile] and (optional) [/textile] tags.');
  }
  else {
    return t('You can use Textile markup to format text.');
  }
}

/**
 * Helper function for preg_replace_callback().
 */
function _textile_match_process($matches) {
  static $textile = NULL;
  $path = textile_library_path();

  if (empty($textile) && $path) {
    require_once DRUPAL_ROOT . '/' . $path . '/classTextile.php';

    $textile = new Textile();
    // $textile->hu is the string that preceeds all relative URLs.
    $textile->hu = url(NULL);
  }

  return is_null($textile) ? $matches[1] : $textile->TextileThis($matches[1]);
}

/**
 * Textile filter. Provides filtering of Textile tags into XHTML.
 */
function _textile_process($text, $filter, $format, $langcode, $cache, $cache_id) {
  if ($filter->settings['textile_tags']) {
    return preg_replace_callback('{\[textile\](.*?)(\[/textile\]|$)}is', '_textile_match_process', $text);
  }
  else {
    return _textile_match_process(array(NULL, $text));
  }
}

/**
 * Settings callback for the Textile filter.
 */
function _textile_settings($form, &$form_state, $filter, $format, $defaults, $filters) {
  $filter->settings += $defaults;
  $settings = array();

  $settings['textile_tags'] = array(
    '#type' => 'checkbox',
    '#title' => t('Use tags'),
    '#default_value' => $filter->settings['textile_tags'],
    '#description' => t('If enabled, only text between [textile] and optional [/textile] tags will be processed; otherwise, all text will be processed as Textile markup.')
  );

  return $settings;
}