<?php
/* freelinking.module -- implements CamelCase and [[free links]] filter for Drupal
   ea. Farris <eafarris@gmail.com>
   portions based on code from crw: http://ninjafish.org/project/wiki

   Drupal freelinking project: http://www.drupal.org/project/freelinking

   $Id: freelinking.module,v 1.31.2.7 2008-10-29 17:40:42 eafarris Exp $
*/

function freelinking_menu($may_cache) {
  global $user;
  $items = array();

  if ($may_cache) {
    $items[] = array(
      'path' => 'freelinking', 
        'title' => t('Freelinks'),
        'access' => user_access('access freelinking list'),
        'callback' => 'freelinking_page',
      );
    $items[] = array(
      'path' => 'admin/settings/freelinking', 
      'title' => t('Freelinking'),
      'description' => t('Configure wiki-style freelinking settings for node content.'),
      'access' => user_access('administer freelinking'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('freelinking_settings'),
    );
  }
  return $items;
} // endfunction freelinking_menu

function freelinking_perm() {
  return array('administer freelinking', 'access freelinking list');
}

function freelinking_page($thetitle = NULL) {

  if ($_POST['operation'] == 'delete' && $_POST['links']) {
    return drupal_get_form('freelinking_multiple_delete_confirm', $_POST['links']);
  } elseif ($_POST['operation'] == 'delete-all') {
    return drupal_get_form('freelinking_delete_all_confirm');
  }

  if ($thetitle) { // find the matching title
    $freelink = _freelinking_make_link($thetitle);
    drupal_goto($freelink['path'], $freelink['args'] ? $freelink['args'] : '');
  }
  else { // no title was passed -- show a list of wikiwords and status
    return drupal_get_form('freelinking_page_form', user_access('administer freelinking'));
  } // big else
} // endfunction freelinking_page

function freelinking_page_form($admin = TRUE) {

  if ($admin) {
    $form['options'] = array('#type' => 'fieldset',
      '#title' => t('Update options'),
      '#prefix' => '<div class="container-inline">',
      '#suffix' => '</div>',
    );
    
    $options = array('delete' => t('Delete'), 'delete-all' => t('Delete All'));
    $form['options']['operation'] = array('#type' => 'select', '#options' => $options,  '#default_value' => 'delete');
    $form['options']['submit'] = array('#type' => 'submit', '#value' => t('Update'));

    $header = array(
      array('data' => theme('table_select_header_cell')),
      array('data' => t('Phrase'), 'field' => 'phrase', 'sort' => 'asc'),
      array('data' => t('Target'), 'field' => 'path'),
    );
  } else {
    $header = array(
      array('data' => t('Phrase'), 'field' => 'phrase', 'sort' => 'asc'),
      array('data' => t('Target'), 'field' => 'path'),
    );
  }

  $query = "SELECT hash, phrase, path FROM {freelinking}" . tablesort_sql($header);
  $result = pager_query($query,50);

  while ($freelink = db_fetch_object($result)) { // looping through phrase, target pairs
    $hash = $freelink->hash;
    $links[$hash] = '';
    $form['phrase'][$hash] = array('#value' => urldecode($freelink->phrase));

    $fltargetnid = _freelinking_exists($freelink->phrase);
    $freelink = _freelinking_make_link($freelink->phrase);
    if ($fltargetnid) {
      $link = l(t('see this content'), drupal_get_path_alias('node/' . $fltargetnid));
    }
    else { // content not found, show link to create
      $link = '<a href="' . url($freelink['path'], $freelink['args']) . '">' . t('create this content') . '</a>';
    }
    $form['target'][$hash] = array('#value' => $link);
  }

  if ($admin) { $form['links'] = array('#type' => 'checkboxes', '#options' => $links); }
  $form['pager'] = array('#value' => theme('pager', NULL, 50, 0));
  return $form;
  
} // endfunction freelinking_page

function theme_freelinking_page_form($form) {
  if (isset($form['options']) && is_array($form['options'])) {
    // Only admins see the options form and the tableselect checkbox
    $output .= drupal_render($form['options']);
    $header = array(
      theme('table_select_header_cell'),
      array('data' => t('Phrase'), 'field' => 'phrase', 'sort' => 'asc'),
      array('data' => t('Target'), 'field' => 'path'),
    );
  } else {
    $header = array(
      array('data' => t('Phrase'), 'field' => 'phrase', 'sort' => 'asc'),
      array('data' => t('Target'), 'field' => 'path'),
    );
  }

  if (isset($form['phrase']) && is_array($form['phrase'])) {
    foreach (element_children($form['phrase']) as $key) {
      $row = array();
      if (isset($form['links'][$key])) { // Only admins see the checkbox
	$row[] = drupal_render($form['links'][$key]);
      }
      $row[] = drupal_render($form['phrase'][$key]);
      $row[] = drupal_render($form['target'][$key]);
      $rows[] = $row;
    }
  } else  {
    $rows[] = array(array('data' => t('No freelinks available.'), 'colspan' => user_access("administer freelinking")?'3':'2'));
  }

  $output .= theme('table', $header, $rows);
  if ($form['pager']['#value']) {
    $output .= drupal_render($form['pager']);
  }

  $output .= drupal_render($form);

  return $output;
}

function freelinking_page_form_validate($form_id, $form_values) {
  $links = array_filter($form_values['links']);
  if (count($links) == 0) {
    form_set_error('', t('No items selected.'));
  }
}


function freelinking_page_form_submit($form_id, $form_values) {
  // Can I assume at this point the user has the right privs, or they wouldn't have been able to render the form in the first place?
  // (probly not, i spose, but we'll make this simplifying assumption for now..)
  $op = $form_values['operation'];

  // Filter out unchecked links
  $links = array_filter($form_values['links']); 

  // perhaps perform other operations besides delete (which requires a confirm form, from the _page callback)
  // maybe this would be better done with a multistep form, that would allow for more complex operations like
  // creating a bunch of nodes at once?
  // for now, don't do anything, and let the _page callback confirm the delete
}

function freelinking_multiple_delete_confirm($links = array()) {
  $form['links'] = array('#prefix' => '<ul>', '#suffix' => '</ul>', '#tree' => TRUE);
  // array_filter returns only elements with TRUE values
  foreach ($links as $hash => $value) {
    $phrase = db_result(db_query('SELECT phrase FROM {freelinking} WHERE hash = "%s"', $hash));
    $form['links'][$hash] = array(
      '#type' => 'hidden', 
      '#value' => $hash, 
      '#prefix' =>  '<li>', 
      '#suffix' => check_plain($phrase) . "</li>\n");
  }
  $form['operation'] = array('#type' => 'hidden', '#value' => 'delete');

  return confirm_form($form,
                      t('Are you sure you want to delete these items?'),
                      'freelinking', t('This action cannot be undone.'),
                      t('Delete all'), t('Cancel'));
}

function freelinking_multiple_delete_confirm_submit($form_id, $form_values) {
  if ($form_values['confirm']) {
    foreach ($form_values['links'] as $hash => $phrase) {
      _freelinking_delete($hash);
    }
    drupal_set_message(t('The freelinks have been deleted.'));
  }
  return 'freelinking';
}

function freelinking_delete_all_confirm() {
  $form['operation'] = array('#type' => 'hidden', '#value' => 'delete-all');
  return confirm_form($form, t('Are you sure you want to delete ALL freelinks?'),
                      'freelinking', t('This action cannnot be undone.'),
                      t('Delete ALL'), t('Cancel'));
}

function freelinking_delete_all_confirm_submit($form_id, $form_values) {
  if ($form_values['confirm']) {
    _freelinking_delete_all();
    drupal_set_message(t('ALL freelinks have been deleted.'));
  }
  return 'freelinking';
}

function freelinking_block($op = 'list', $delta = 0) {
  switch ($op) {
    case 'list':
      $blocks[0]['info'] = t('Freelink targets that need to be created');
      return $blocks;
      break;
    case 'configure':
      $form['freelinking_block_options'] = array(
        '#type' => 'fieldset',
        '#title' => t('Freelinking Block Options')
      );
      $form['freelinking_block_options']['freelinking_blocktitle'] = array(
        '#title' => t('Title of freelinks block'),
        '#type' => 'textfield',
        '#default_value' => variable_get('freelinking_blocktitle', t('Create This Content')),
        '#size' => 30,
        '#maxlength' => 60,
        '#description' => t('Title of the block that shows freelinked phrases without content.')
      );
      for ($i = 5; $i <=30; $i=$i+5) {
        $options[$i] = $i;
      }
      $form['freelinking_block_options']['freelinking_blocknum'] = array(
        '#title' => t('Number of non-existing link phrases to show'),
        '#type' => 'select',
        '#options' => $options,
        '#default_value' => variable_get('freelinking_blocknum', '10'),
        '#description' => t('Number of phrases to show in the block.')
      );
      return $form;
      break;
      
    case 'view':
      switch ($delta) {
        case 0:
          $query  = 'SELECT * FROM {freelinking} WHERE path LIKE "%node/add%" ORDER BY RAND()';
          $query .= ' LIMIT ' . variable_get('freelinking_blocknum', 10);
          $result = db_query($query);
          $content = '';
          while ($freelink = db_fetch_object($result)) {
            $items[] = l(urldecode($freelink->phrase), 'freelinking/' . $freelink->phrase);
          } // endwhile looping through flpairs
          $block['subject'] = variable_get('freelinking_blocktitle', 'Create This Content');
          $block['content'] = theme('item_list', $items);
          return $block;
        default:
          break;
      } // endswitch $delta
    default:
      break;
  } // endswitch $op
} // endfunction freelinking_block

function freelinking_settings() {
  $notfoundoptions = array(
    'create only' => t('Only try to create content'),
    'no access search' => t('Search for content if user can\'t create'),
    'always search' => t('Always search for content'),
  );
  $form["freelinking_nodetype"] = array(
    '#title' => t('Default for new content'),
    '#type' => 'select',
    '#options' => node_get_types('names'),
    '#default_value' => variable_get("freelinking_nodetype", 'story'),
    '#description' => t('Type of content that the freelinking filter will create when clicking on a freelink without a target.')
  );
  $form['freelinking_notfound'] = array(
    '#title' => t('What to do if content not found'),
    '#type' => 'select',
    '#options' => $notfoundoptions,
    '#default_value' => variable_get('freelinking_notfound', 'no access search'),
    '#description' => t('What to do when clicking on a freelink without a target. Choose to always attempt to create the content, search if the user doesn\'t have permission to create (the default), or to always search. NOTE: search functions require search.module to be activated.'),
  );

  $form["freelinking_restriction"] = array(
    '#title' => t('Restrict free links to this content type'),
    '#type' => 'select',
    '#options' => array_merge(array('none' => t('No restrictions')), node_get_types('names')),
    '#default_value' => variable_get("freelinking_restriction", 'none'),
    '#description' => t('If desired, you can restrict the freelinking title search to just content of this type. Note that if it is not the same as the "Default for new content," above, new freelinked content cannot be found.')
  );
  $form["freelinking_camelcase"] = array(
    '#title' => t('Allow CamelCase linking'),
    '#type' => 'checkbox',
    '#default_value' => variable_get("freelinking_camelcase", 1) == 1 ? TRUE : FALSE,
    '#description' => t('If desired, you can disable CamelCase linking')
  );
  $form["freelinking_onceonly"] = array(
    '#title' => t('Only link first occurrence'),
    '#type'  => 'checkbox',
    '#default_value' => variable_get("freelinking_onceonly", 0) == 1 ? TRUE : FALSE,
    '#description' => t('If desired you can only turn the first occurrence of a freelink into a link. This can improve the appearance of content that includes a lot of the same CamelCase words.')
  );

  return system_settings_form($form);
}


function freelinking_filter($op, $delta = 0, $format = -1, $text = '') {
  switch ($op) {
    case 'list':
      return (array(0 => t('freelinking filter')));
      break;

    case 'name':
      return t('freelinking filter');
      break;
    
    case 'description':
      return t('Enables freelinking between nodes with CamelCase or delimiters like [[ and ]].');
      break;

    case 'process':
      return _freelinking_do_filtering($text, FALSE);
      break;

    case 'prepare':
      return $text;
      break;

  } // endswitch $op
} // endfunction freelinking_filter

function freelinking_nodeapi(&$node, $op, $teaser = NULL, $page = NULL) {
  switch ($op) {
    case 'update':
      _freelinking_do_filtering($node->body, TRUE);
      break;
    case 'insert':
      _freelinking_do_filtering($node->body, TRUE);
      break;
  } // endswitch $op
} // endfunction freelinking_nodeapi

function freelinking_filter_tips($delta, $format, $long = FALSE) {
  if ($long) {
    $output  = t('Content in [[double square brackets]] will be linked to existing content with that title, or a page to create that content. ');
    $output .= t('Links can contain an optional bar, "|". Content on the left of the bar is the target; to the right, the link shown. ');
    $output .= t('Links to pages outside this site are allowed. They must start with one of the following: "http", "https", "ftp", or "mailto", and can exist either by themselves, or on the left of the bar. ');
    $output .= t('Examples: ');
    $ouptut .= t('<ul>');
    $output .= t('<li>[[simple link]] - will go to the content titled "simple link" or a page to create that content.</li>');
    $output .= t('<li>[[this is the target|this is the source]] - will present "this is the source" as a link to "this is the target", or a page to create that content.</li>');
    $output .= t('<li>[[http://www.example.com|this is the source]] - will present "this is the source" as a link to http://www.example.com.</li>');
    $output .= t('<li>[[http://www.example.com]] - will present "http://www.example.com" as a link to http://www.example.com.</li>');
    $output .= t('</ul>');
    if (variable_get('freelinking_camelcase', TRUE)) {
      $output .= t('Content consisting of two or more capitalized words run together (aka "CamelCase") will be linked to existing content with that title, or a page to create that content.');
    }
  }
  else { // short tips displayed in-line
    $output  = t('Link to content with [[some text]], where "some text" is the title of existing content or the title of a new piece of content to create. You can also link text to a different title by using [[link to this title|show this text]]. ');
    $output .= t('Link to outside URLs with [[http://www.example.com|some text]], or even [[http://www.example.com]]. ');
    if (variable_get('freelinking_camelcase', TRUE)) {
      $output .= t('Link to existing or new content with CamelCaseWords.');
    }
  }
  return $output;
}

function freelinking_form_alter($form_id, &$form) {
  $type = $form['type']['#value'];

  if (variable_get('freelinking_nodetype', 'story') == $type && $_GET['edit']) { // on the right node type, with GET data
    $form['title']['#default_value'] = urldecode($_GET['edit']['title']); // prepopulate the title field
  } // endif node type and data
} // endfunction freelinking_form_alter
    

/* 
 * PRIVATE FUNCTIONS BELOW
 *
 * Please do not use these functions outside of freelinking.module, as they are
 * subject to change without notice.
 *
*/

function _freelinking_do_filtering($text, $store = FALSE) {
  $allowcamelcase = variable_get("freelinking_camelcase", TRUE);
  $freelinkingregexp = '/\[\[.+]]/U'; // this finds [[links like this]], un-greedily
  preg_match_all($freelinkingregexp, $text, $flmatches);
  if ($allowcamelcase) {
     $camelcaseregexp = '/\b([[:upper:]][[:lower:]]+){2,}\b/'; // this gets us close, but is not perfect. Example: ThisIsACamelCaseWord won't match (two caps in a row)
     preg_match_all($camelcaseregexp, $text, $ccmatches);
     $wikiwords = array_merge($ccmatches[0], $flmatches[0]);
  }
  else {
     $wikiwords = $flmatches[0];
  }
  foreach (array_unique($wikiwords) as $wikiword) {
    if (substr($wikiword, 0, 2) == '[[') { // if it's a freelink, the expressions are different
      $phrase = substr($wikiword, 2, -2);
      $freelink = $phrase;
      $barpos = strpos($phrase, '|');
      $pattern = '/\[\[' . preg_quote($phrase,'/') . ']]/';
      if ($barpos) {
         $freelink = substr($freelink, 0, $barpos);
         $phrase = substr($phrase, $barpos + 1);
      }
      if (preg_match('/^(https?|mailto|ftp):/', $freelink)) {
         $replacement = '<a class="freelinking external" href="' . $freelink . '">' . $phrase . '</a>';
         $store = FALSE;
      }
      else {
        $replacement = l($phrase, 'freelinking/' . rawurlencode($freelink), array('class' => 'freelinking'));
      }
    }

    else if ($allowcamelcase) { // it's a CamelCase, expressions are a bit simpler
      $pattern = '/\b' . $wikiword . '\b(?![^<]*>)/';
      $phrase = $wikiword; // consistency for the db
      $freelink = $wikiword; // also for the db
      $replacement = l($wikiword, 'freelinking/' . urlencode($wikiword));
    }
    $text = preg_replace($pattern, $replacement, $text, variable_get("freelinking_onceonly", 0) ? 1 : -1);
    if (variable_get('freelinking_onceonly', 0)) {
      $text = preg_replace($pattern, $phrase, $text);
    }

    if ($store) {
      _freelinking_store($freelink, $replacement);
    }
  } // foreach wikiword
  return $text;
} // endfunction _freelinking_do_filtering

function _freelinking_store($phrase, $path, $args=NULL) { // store freelinking pair in the db
  $hash = md5($phrase . $path . $args);
  $query = "SELECT hash FROM {freelinking} WHERE phrase = '%s'";
  $result = db_query($query, $phrase); 
  if ( !db_num_rows($result)) { // not in the db
    $query = "INSERT INTO {freelinking} (hash, phrase, path, args) VALUES ('%s', '%s', '%s', '%s')";
    $result = db_query($query, $hash, $phrase, $path, $args);
  } // endif row not found in table
  else { // in the db, but does it match?
    $dbhash = db_fetch_object($result);
    if ($dbhash->hash != $hash) { // hashes don't match, replace db entry with new values
      $query = "UPDATE {freelinking} SET hash = '%s', path = '%s', args = '%s' WHERE phrase = '%s'";
      $result = db_query($query, $hash, $path, $args, $phrase);
    } // endif hashes don't match
  } // endifelse row found
} // endfunction _freelinking_store

function _freelinking_delete($hash) {
  $query = "DELETE FROM {freelinking} WHERE hash = '%s'";
  $result = db_query($query, $hash);
   // do something with result?
}

function _freelinking_delete_all() {
  db_query("DELETE FROM {freelinking}");
}

function _freelinking_exists($thetitle) { // helper function for freelinking_page
  // looks through the db for nodes matching $title. Returns the nid if such a node exists, otherwise, returns 0
  $title = urldecode($thetitle);
  $query = "SELECT nid, type FROM {node} WHERE title = '%s'";
  $result = db_query($query, $title);
// FIXME ***
  while ($node = db_fetch_object($result)) { // only one, I hope... what if there's more than one?
    $nid = $node->nid;
    $type = $node->type;
  }

  // no nid on a title search; search aliases
  if (empty($nid)) {
    $query = "SELECT src FROM {url_alias} WHERE dst = '%s'";
    $result = db_query($query, $title);
    while ($realpath = db_fetch_object($result)) {
      preg_match("/node\/([0-9]+)/",$realpath->src, $nids);
      $nid = $nids[1];
      $query = "SELECT type FROM {node} WHERE nid = %d"; // get type of node
      $result = db_query($query, $nid);
      $node = db_fetch_object($result);
    } // endwhile looping through (one) alias
  } // endif no match on title

  // now we've got the $nid and $node->type. Check for restrictions
  $noderestrict = variable_get('freelinking_restriction', 'none');
  if ($noderestrict != 'none') { // restrictions in effect
    if ($noderestrict != $type) { // node type is not allowed
      return 0;
    } // endif node type doesn't match
  } // restrictions in effect

  return (empty($nid) ? 0 : $nid);
}


function _freelinking_make_link($thetitle) { // helper function for freelinking_page
  global $user;
  // Returns a link to a node named $thetitle if found, or a link to new content otherwise.
  $nid = _freelinking_exists($thetitle); 
  if ($nid) { // the node exists, set the path to go there
    $freelink['path'] = 'node/' . $nid;
  }
  else { // node doesn't exist, set path to create it
    switch (variable_get('freelinking_notfound', 'no access search')) {
      case 'create only':
        $freelink['path'] = 'node/add/' . variable_get('freelinking_nodetype', 'story');
        $freelink['args'] = 'edit[title]=' . $thetitle;
        break;
      case 'no access search':
        if (node_access('create', variable_get('freelinking_nodetype', 'story'))) {
          $freelink['path'] = 'node/add/' . variable_get('freelinking_nodetype', 'story');
          $freelink['args'] = 'edit[title]=' . $thetitle;
        }
        else {
          $freelink['path'] = 'search/node/' . $thetitle;
        }
        break;
      case 'always search':
        $freelink['path'] = 'search/node/' . $thetitle;
        break;
    } // endswitch notfound options
  }
  _freelinking_store($thetitle, $freelink['path'], $freelink['args']);
  return $freelink;
} // endfunction _freelinking_make_link

// vim: tw=300 nowrap syn=php