<?php
// $Id: freelinking.module,v 1.32.2.11.2.2.2.28 2010-05-04 16:19:02 grayside Exp $
/**
 * Freelinking 3
 *
 * @file
 *   Provides flexible, extensible linking of content, wiki-style
 */

require (drupal_get_path('module', 'freelinking') . '/freelinking.utilities.inc');
require (drupal_get_path('module', 'freelinking') . '/freelinking.forms.inc');

/**
 * Implementation of hook_menu().
 */
function freelinking_menu() {
  $items['admin/settings/freelinking'] = array(
    'title' => 'Freelinking settings',
    'description' => 'Configure settings for the freelinking input filter',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('freelinking_settings'),
    'access arguments' => array('administer freelinking'),
  );
  return $items;
} // endfunction freelinking_menu

/**
 * Implementation of hook_perm().
 */
function freelinking_perm() {
  return array('administer freelinking');
}

/**
 * Implementation of hook_filter().
 */
function freelinking_filter($op, $delta = 0, $format = -1,
  $text = '', $langcode = '', $cache_id = 0) {

  switch ($op) {
    case 'list':
      return array(0 => 'freelinking filter');
    case 'no cache':
      return !freelinking_get_conf('cache');
    case 'description':
      return t('Allows for a flexible format for linking content');
    case 'process':
      $freelinking = freelinking_get_plugins();
      $defaultplugin = variable_get('freelinking_default', 'nodetitle');
      $syntax = variable_get('freelinking_match_syntax', 'double_bracket');
      $regex = _freelinking_match_pattern();

      // Loop through every freelink format
      // Space at text start prevents match failure at start.
      preg_match_all($regex[$syntax], ' ' . $text, $matches, PREG_SET_ORDER);

      foreach ($matches as $match) {
        $current_plugin = '';

        // in markdown mode, the first match is part of the target.
        // This is hacky and temporary while matching is in transition.
        if ($syntax == 'markdown') {
          if (!$match[4]) {
            $match[4] = $match[3];
          }
          else {
            $match[4] = $match[3] . ':' . $match[4];
          }
          // encode pipes in Title.
          $match[2] = urlencode($match[2]);
          $match[1] = $match[4] . '|' . $match[2] . '|' . $match[5];
        }

        // default freelink (no colon)
        if (strpos($match[1], ':') === FALSE) {
          $current_plugin = $defaultplugin;
          $target = $match[1];
        } // end default freelink
        else {
          $delim = strpos($match[1], ':');
          $indicator = substr($match[1], 0, $delim);
          $target = substr($match[1], $delim+1);
          // find a plugin for the match
          foreach (array_keys($freelinking) as $plugin) {
            if ($plugin['enabled']
              && preg_match($freelinking[$plugin]['indicator'], $indicator)) {
                $current_plugin = $plugin;
            }
          }// end looping through plugins
        } // end non-default freelinks
        $target = freelinking_parse_target($target, $current_plugin);
        $link = freelinking_get_freelink($current_plugin, $target);

        if ($link) {
          $text = str_replace($match[0], $link, $text);
        }
      }
      return $text;
    case 'prepare':
    default:
      return $text;
  } // endswitch $op
} // endfunction freelinking_filter

/**
 * Implementation of hook_freelinking().
 * Include plugins/*.inc plugins
 */
function freelinking_freelinking() {
  $files = file_scan_directory(
    drupal_get_path('module', 'freelinking') . '/plugins/', '.inc');
  foreach ($files as $absolute => $file) {
    require $absolute;
  }
  foreach ($freelinking as $plugin => $definition) {
    if (!$definition['settings']) {
      $freelinking[$plugin]['settings'] = 'freelinking_' . $plugin . '_settings';
    }
  }
  return $freelinking;
}

/**
 * Implementation of hook_freelink_alter().
 * Used here to clean up and standardize links.
 */
function freelinking_freelink_alter(&$link, $target, $plugin_name, $plugin) {
  // not a valid link
  if (!$link[1]) {
    $link['error'] = t('Invalid Link');
    return;
  }
  // title text is empty, insert from target or use URL
  if (!$link[0]) {
    $link[0] = $target['text'] ? $target['text'] : $target['target'];
  }

  // support html link text unless plugin overrides
  if ($plugin['html'] !== FALSE) {
    $link[2]['html'] = TRUE;
  }

  // Set an empty tooltip as the URL (unless the target has one)
  if (!$link[2]['attributes']['title']) {
    $link[2]['attributes']['title'] =
      $target['tooltip'] ? $target['tooltip'] : $link[1];
  }

  // standard set of CSS classes
  $link[2]['attributes']['class'] = rtrim('freelink freelink-'
    . strtr($plugin_name, ' ', '-') . ' ' . $link[2]['attributes']['class']);

  // There was more than one effort to generate the link
  if (isset($target['other']['trace'])) {
    $link[2]['attributes']['class'] .= ' notfound';
  }

  // Is this an internal or external link?
  $parts = parse_url($link[1]);
  if ($parts['host'] && $parts['host'] != $_SERVER['SERVER_NAME']) {
    $link[2]['attributes']['class'] .= ' freelink-external';
  }
  else {
    $link[2]['attributes']['class'] .= ' freelink-internal';
  }
}

/**
 * Implementation of hook_filter_tips().
 */
function freelinking_filter_tips($delta, $format, $long = FALSE) {
  $syntax = variable_get('freelinking_syntax_mode', 'double_bracket');
  if ($syntax == 'double_bracket') {
    $pattern = '<tt>[[indicator:target|Title]]</tt>';
  }
  elseif ($syntax == 'markdown') {
    $pattern = '<tt>[Title](indicator:target)</tt>';
  }
  else {
    $pattern = '<tt>[indicator:target|Title]</tt>';
  }
  $text .= t('Freelinking helps you easily create HTML links. Links take the form of !pattern.',
    array('!pattern' => $pattern));

  $plugins = freelinking_get_plugins();

  if ($long == FALSE) {
    $default_tip = $plugins[variable_get('freelinking_default', 'nodetitle')]['tip'];
    if ($default_tip) {
      $text .= ' By default (no indicator): ' . $default_tip;
    }
    return $text;
  }

  $text = '<h4>' . t('Freelinking') . '</h4>' . $text;
  $text .= '<br />';
  $text .= t('Below is a list of available types of freelinks you may use, organized as <strong>Plugin Name</strong>: <em>[indicator]</em>.');

  foreach ($plugins as $name => $plugin) {
    $tips[$name] = '<strong>' . drupal_ucfirst($name) .'</strong> <em>[' . $plugin['indicator'] . ']</em>';
    if ($plugin['tip']) {
      $tips[$name] .= ' — ' . $plugin['tip'];
    }
  }
  $text .= theme('item_list', $tips);
  return $text;
}

/**
 * Construct a link out of the $target with the specified plugin
 */
function _freelinking_build_freelink($freelinking, $plugin_name, $target) {
  // by default return false so no replacement happens
  $plugin =& $freelinking[$plugin_name];

  // if a plugin does not exist, go to failure.
  if (!$plugin) {
    return array('error' => t('Plugin %plugin Not Found',
      array('%plugin' => $plugin_name)));
  }

  // run the text through translation
  if ($plugin['translate']) {
    $target['dest'] = strtr($target['dest'], $plugin['translate']);
  }

  // process simple replacement plugins if no callback exists
  if ($plugin['replacement'] && !$plugin['callback']) {
    // %1 is the token all freelinking replacement strings must include
    $url = preg_replace('/%1/', $target['dest'], $plugin['replacement']);
    $link = array('', $url);
  }

  // process replacement callback
  if (function_exists($plugin['callback'])) {
    $link = call_user_func_array($plugin['callback'],
      array($target, $plugin));
  }

  // Standardize link, grab authoritative "structured" version
  // designate the rendered text for display
  if (is_array($link)) {
    if ($link['failover'] && $link['failover'] != 'error' && $link['failover'] != 'none') {
      $target = $link['target'] ? $link['target'] : $target;
      $target['other']['trace'][] = $plugin_name;
      unset($freelinking[$plugin_name]);
      return _freelinking_build_freelink($freelinking, $link['failover'], $target);
    }
    if (is_array($link) && !$link['error']) {
      drupal_alter('freelink', $link, $target, $plugin_name, $plugin);
    }
  }
  // if empty/false, nothing will happen
  return $link;
}

/**
 * Parse target for secondary link arguments.
 * This is raw user input and needs to be checked by the HTML Filter.
 */
function freelinking_parse_target($target, $plugin = NULL, $separator = NULL) {
  if (!$separator) {
    $separator = '|';
  }

  $args = array();
  $args['target'] = $target;
  $items = explode($separator, $target);
  // first three unnamed args are dest, text, tooltip
  $index = 0;
  foreach ($items as $key => $item) {
    if (strpos($item, '=')) {
      list($name, $value) = explode('=', $item);
      $args[$name] = $value;
    }
    elseif ($index < 3) {
      switch($index) {
        case '0':
          $args['dest'] = $item;
          break;
        case '1':
          $args['text'] = $item;
          break;
        case '2':
          $args['tooltip'] = $item;
          break;
      }
      $index++;
    }
    else {
      $args['other'][] = $item;
    }
  }
  // Convert URL-encoded text into something readable for link text & tooltip.
  $args['text'] = urldecode($args['text']);
  $args['tooltip'] = urldecode($args['tooltip']);
  return $args;
}

/**
 * Theme Functions
 */

/**
 * Implementation of hook_theme().
 */
function freelinking_theme() {
  return array(
    'freelink' => array('theme_freelink', 'plugin' => NULL, 'link' => NULL),
    'freelink_error' => array('theme_freelink', 'plugin' => NULL, 'message' => NULL),
  );
}

/**
 * Theme the Freelink
 */
function theme_freelink($plugin = NULL, $link = NULL) {
  if ($link['extra']) {
    $prefix = $link['extra']['prefix'];
    $suffix = $link['extra']['suffix'];
    unset($link['extra']);
  }
  
  $rendered = $prefix . call_user_func_array('l', $link) . $suffix;
  return $rendered;
}

/**
 * Theme the error message
 */
function theme_freelink_error($plugin = NULL, $message = NULL) {
  if ($message) {
    $message = ': ' . $message;
  }
  return '<code class="freelink freelink-error freelink-'
    . $plugin . ' freelink-error-' . $plugin . '">['
    . t('Bad Link') . $message . ']</code>';
}


/**
 * Helper Functions
 */

/**
 * Collect freelink format patterns for filtering.
 */
function _freelinking_match_pattern($separator = NULL) {
  if (!$separator) {
    $separator = ':';
  }
  $separator = preg_quote($separator);

  $option['double_bracket'] =
    '/(?<!\\\\)\[\[(.+' . $separator . '?.+)]]/Uu';
  $option['single_bracket'] =
    '/(?<!\\\\)\[(.+' . $separator . '?.+)]/Uu';
  $option['markdown'] =
    '/(?<!\\\\)(\[([^\]]+)\]\((.+)(?:' . $separator . '(.+))?(?:\s"(.+)")?\))/Uu';
  return $option;
}

// vim: tw=300 nowrap syn=php