<?php
// $Id: wikitools.module,v 1.1.2.3 2008-01-05 03:40:43 cwgordon7 Exp $

/**
 * @file
 * A non-intrusive module to have some wiki-like behaviour.
 */

/**
 * Implementation of hook_help().
 */
function wikitools_help($section) {
  switch ($section) {
    case 'admin/help#wikitools':
      $output = '<p>' . t('The wikitools module allows you to set several options for your content to get a more wiki-like behaviour.') . '</p>';
      return $output;
      break;
  }
}

/*
 * Setup functions
 */

/**
 * Implementation of hook_menu().
 */
function wikitools_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/settings/wikitools',
      'title' => t('Wikitools'),
      'description' => t('Settings for wiki-like behaviour.'),
      'access' => user_access('administer site configuration'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('wikitools_admin_settings'),
      'type' => MENU_NORMAL_ITEM
    );
  }
  else {
    $wiki_path = wikitools_wiki_path();
    if ($wiki_path) {
      $items[] = array(
        'path' => $wiki_path,
        'callback' => 'wikitools_handle_request',
        'access' => user_access('access content'),
        'type' => MENU_CALLBACK
      );
    }
    // Override the callback for node deletion if the delete protection option is set.
    if (arg(0) == 'node' && is_numeric(arg(1))) {
      $node = node_load(arg(1));
      if (wikitools_type_affected($node->type) && wikitools_delete_protection()) {
        // Hijack delete callback and call custom handler.
        $items[] = array('path' => 'node/'. arg(1) .'/delete', 'title' => t('Delete'), 
          'callback' => 'wikitools_delete_protection_delete_confirm',
          'callback arguments' => array($node),
          'access' => node_access('delete', $node),
          'weight' => 1,
          'type' => MENU_CALLBACK
        );
      }
    }
    // Only hijack freelinking path if an argument is specified, otherwise let the freelinking page show.
    if (wikitools_hijack_freelinking() && arg(1)) {
      $items[] = array(
        'path' => 'freelinking',
        'callback' => 'wikitools_handle_request',
        'access' => user_access('access content'),
        'type' => MENU_CALLBACK
      );
    }
  }
  return $items;
}

/**
 * Builder function for settings form.
 */
function wikitools_admin_settings() {
  $form = array();

  $form['wikitools_path'] = array(
    '#type' => 'textfield',
    '#title' => t('Wiki path'),
    '#default_value' => wikitools_wiki_path(),
    '#description' => t('The drupal path for the wiki. Do not include a trailing slash. Leave empty to disable the wiki path.'),
    '#field_prefix' => url(NULL, NULL, NULL, TRUE) . (variable_get('clean_url', 0) ? '' : '?q=')
  );
  $form['wikitools_main_page_title'] = array(
    '#type' => 'textfield',
    '#title' => t('Title of main page'),
    '#default_value' => wikitools_main_page_title(),
    '#description' => t('The main page is shown if you type in the wiki path. Leave empty to disable the main page.'),
  );
  $form['wikitools_node_types'] = array(
    '#type' => 'select',
    '#title' => t('Wiki node types'),
    '#options' => node_get_types('names'),
    '#size' => count(node_get_types('names')),
    '#default_value' => wikitools_node_types(),
    '#multiple' => TRUE,
    '#description' => t('Select the node types which will be affected by the specified options. If you select multiple node types, all nodes of these types will be searched for when a wikipath is entered. If a wikipage doesn\'t exist, an option to create any of these types will be given.'),
  );
  $form['wikitools_options'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Options'),
    '#options' => array(
      'node creation' => t('Node Creation: Let users create new nodes when they type in a node name which does not exist.'),
      'node search' => t('Node Search: Let users search for nodes when they type in a node name which does not exist.'),
      'auto redirect' => t('Automatic Redirect: If a title of a moved page is entered, redirect automatically.'),
      'unique titles' => t('Unique Titles: Enforce that titles are unique over all wiki node types'),
      'move protection' => t('Move Protection: Disallow change of node titles for users without <em>administer nodes</em> permission.'),
      'delete protection' => t('Delete Protection: Disallow deletion of nodes for users without <em>administer nodes</em> permission.'),
      'underscore as space' => t('Treat underscores as spaces when looking for node titles.'),
      'dash as space' => t('Treat dashes as spaces when looking for node titles.'),
    ),
    '#default_value' => wikitools_options(),
    '#description' => '<ul><li>'.
      t('To take full advantage of the options <em>Node Creation</em>, <em>Node Search</em> and <em>Automatic Redirect</em> you should use an input format which creates wikilinks which point to the wiki path set. For exapmle a wikilink [[Page Name]] should be linked to <em>wikipath/Page Name</em>.') .'</li><li>'. 
      t('The options <em>Node Creation</em>, <em>Node Search</em> and <em>Automatic Redirect</em> work only if a wiki path is set or if freelinking hijacking is enabled. They take the page name from the path after the wiki path, i.e. <em>wikipath/Page Name</em>, or the page name of a freelinking link, i.e. <em>freelinking/Page Name</em>.') .'</li><li>'.
      t('The option <em>Automatic Redirect</em> works only if node revisions are created.') .'</li></ul>',
  );
  $form['wikitools_disallowed_characters'] = array(
    '#type' => 'textfield',
    '#title' => t('Disallowed characters in titles'),
    '#description' => t('A list of characters which are not allowed in the title of a wiki page. This setting is important for the wikilink feature to work. Set it so that your input syntax will not be confused by titles. Make sure you don\'t enter a space character unless you really want to disallow spaces in titles. Leave empty to disable this feature.'),
    '#default_value' => wikitools_disallowed_characters(),
  );
  $form['wikitools_hijack_freelinking'] = array(
    '#type' => 'checkbox',
    '#title' => t('Hijack freelinking filter'),
    '#default_value' => wikitools_hijack_freelinking(),
    '#description' => t('If you activate this option, the links of the freelinking filter will be processed by the wikitools module rather than the freelinking module. When active, a link to <em>freelinking/Page Name</em> behaves exactly as a link to <em>wikipath/Page Name</em>.'),
  );
  return system_settings_form($form);
}

/**
 * Implementation of hook_requirements().
 */
function wikitools_requirements($phase) {
  // Don't check when installing
  if ($phase == 'install') {
    return;
  }
  if (wikitools_hijack_freelinking()) {
    wikitools_autoadjust();
  }
}

/**
 * Adjust the module weights for wikitools to load after freelinking module.
 */
function wikitools_autoadjust() {
  $modules = array_keys(module_list());
  if (array_search('wikitools', $modules) <= array_search('freelinking', $modules)) {
    $freelinking_module_weight = db_result(db_query("SELECT weight FROM {system} WHERE name='freelinking'"));
    db_query("UPDATE {system} SET weight=%d WHERE name='wikitools'", $freelinking_module_weight + 1);
    drupal_set_message(t('Weight of %wikitools module set to %weight.', array('%wikitools' => t('wikitools'), '%weight' => $wikitools_module_weight + 1)));
  }
}

/*
 * Settings
 */

/**
 * Drupal path of wiki.
 */
function wikitools_wiki_path($value = NULL) {
  if (is_null($value)) {
    return variable_get('wikitools_path', 'wiki');
  }
  variable_set('wikitools_path', $value);
}

/**
 * Title of node on root path of wiki.
 */
function wikitools_main_page_title($value = NULL) {
  if (is_null($value)) {
    return variable_get('wikitools_main_page_title', 'Main Page');
  }
  variable_set('wikitools_main_page_title', $value);
}

/**
 * Node types of wiki pages.
 */
function wikitools_node_types($value = NULL) {
  if (is_null($value)) {
    return variable_get('wikitools_node_types', array());
  }
  variable_set('wikitools_node_types', $value);
}

/**
 * Is node type affected by wikitool options?
 */
function wikitools_type_affected($type) {
  static $node_types = NULL;
  if (is_null($node_types)) {
    $node_types = wikitools_node_types();
  }
  return isset($node_types[$type]) && $node_types[$type];
}

/**
 * String of characters which are not allowed in a wiki page title.
 */
function wikitools_disallowed_characters($value = NULL) {
  if (is_null($value)) {
    return variable_get('wikitools_disallowed_characters', '[]{}|');
  }
  variable_set('wikitools_disallowed_characters', $value);
}

/**
 * Various wikitool options.
 */
function wikitools_options($value = NULL) {
  if (is_null($value)) {
    return variable_get('wikitools_options', array('node creation', 'node search', 'delete protection', 'move protection', 'unique titles', 'auto redirect', 'underscore as space', 'dash as space'));
  }
  return variable_set('wikitools_options', $value);
}

/**
 * Is node creation activated?
 */
function wikitools_node_creation() {
  $options = wikitools_options();
  return $options['node creation'];
}

/**
 * Is node search activated?
 */
function wikitools_node_search() {
  $options = wikitools_options();
  return $options['node search'];
}

/**
 * Is delete protection activated?
 */
function wikitools_delete_protection() {
  $options = wikitools_options();
  return $options['delete protection'];
}

/**
 * Is move protection activated?
 */
function wikitools_move_protection() {
  $options = wikitools_options();
  return $options['move protection'];
}

/**
 * Is automatic redirection activated?
 */
function wikitools_auto_redirect() {
  $options = wikitools_options();
  return $options['auto redirect'];
}

/**
 * Are unique titles enforced?
 */
function wikitools_enforce_unique_titles() {
  $options = wikitools_options();
  return $options['unique titles'];
}

/**
 * Are underscore characters treated as spaces?
 */
function wikitools_treat_underscore_as_space() {
  $options = wikitools_options();
  return $options['underscore as space'];
}

/**
 * Are dashes treated as spaces?
 */
function wikitools_treat_dash_as_space() {
  $options = wikitools_options();
  return $options['dash as space'];
}

/**
 * Is the freelinking path hijacked?
 */
function wikitools_hijack_freelinking($value = NULL) {
  if (is_null($value)) {
    return variable_get('wikitools_hijack_freelinking', TRUE);
  }
  variable_set('wikitools_hijack_freelinking', $value);
}

/*
 * Operations
 */

/**
 * Menu callback for wiki path.
 * This function is called if a page without an alias is called below the wiki path.
 */
function wikitools_handle_request() {
  // Calculate index of first path argument after wiki path.
  $i = count(explode('/',wikitools_wiki_path()));
  if (arg($i)) {
    // Save the path arguments after the wiki path as page name and put the slashes back.
    $page_name = arg($i++);
    while (arg($i)) {
      $page_name .= '/' . arg($i);
      $i++;
    }
  }
  else {
    // Use default page title if only wiki path is entered.
    $page_name = wikitools_main_page_title();
  }
  // Decode page name and remove white space.
  $page_name = trim(urldecode($page_name));
  if (wikitools_treat_underscore_as_space()) {
    $page_name = str_replace('_', ' ', $page_name);
  }
  if (wikitools_treat_dash_as_space()) {
    $page_name = str_replace('-', ' ', $page_name);
  }

  $node_types = wikitools_node_types();
  $output = '';
  // Don't do anything if no node types are active or no page name is available
  if (count($node_types) && $page_name) {
    // Try to find the current page with this name.
    $result = db_query("SELECT nid, type FROM {node} WHERE LOWER(title) = LOWER('%s')", $page_name);
    $found_nodes = array();
    while ($node = db_fetch_object($result)) {
      if (wikitools_type_affected($node->type)) {
        $found_nodes[] = $node;
      }
    }
    if (count($found_nodes) == 1) {
      // Single match for title.
      $node = current($found_nodes);
      drupal_goto("node/$node->nid");
    }
    else if (count($found_nodes) > 1) {
      // Multiple match for title.
      drupal_set_title('Page found: '. $page_name);
      $output .= theme('wikitools_page_found', $page_name, $found_nodes);
    }
    else {
      // No match for title. Try to find an old page with this name
      $result = db_query("SELECT n.nid, n.type, n.title FROM {node} n LEFT JOIN {node_revisions} r ON n.nid = r.nid WHERE LOWER(r.title) = LOWER('%s') ORDER BY n.vid DESC", $page_name);
      $moved_nodes = array();
      while ($node = db_fetch_object($result)) {
        if (wikitools_type_affected($node->type)) {
          $moved_nodes[] = $node;
        }
      }
      if (count($moved_nodes) > 0 && wikitools_auto_redirect() && !isset($_REQUEST['noredirect'])) {
        $node = current($moved_nodes);
        drupal_set_message(t('Redirected from <a href="@url">%page</a>', array('%page' => $page_name, '@url' => wikitools_wikilink_url($page_name, 'noredirect'))));
        drupal_goto("node/$node->nid");
      }
      else if (count($moved_nodes) > 0) {
        drupal_set_title('Page moved: '.$page_name);
        $output = theme('wikitools_page_moved', $page_name, $moved_nodes);
      }
      else {
        drupal_set_title('Page does not exist: '. $page_name);
        $output = theme('wikitools_page_does_not_exist', $page_name);
      }
    }
  }
  return $output;
}

/**
 * Implementation of hook_nodeapi().
 */
function wikitools_nodeapi(&$node, $op, $form = NULL, $a4 = NULL) {
  switch($op) {
    case 'validate':
      wikitools_node_validate($node);
      break;
  }
}

/**
 * Validate check of node edit form.
 */
function wikitools_node_validate($node) {
  if (wikitools_type_affected($node->type)) {
    if (wikitools_enforce_unique_titles()) {
      $nid = db_result(db_query("SELECT nid FROM {node} WHERE LOWER(title) = LOWER('%s')", $node->title));
      if (!$nid && wikitools_treat_underscore_as_space()) {
        $nid = db_result(db_query("SELECT nid FROM {node} WHERE LOWER(REPLACE(title, '_', ' ')) = LOWER(REPLACE('%s', '_', ' '))", $node->title));
      }
      if (!$nid && wikitools_treat_dash_as_space()) {
        $nid = db_result(db_query("SELECT nid FROM {node} WHERE LOWER(REPLACE(title, '-', ' ')) = LOWER(REPLACE('%s', '-', ' '))", $node->title));
      }
      // It is only an error if the node which alredy exists is not the currently edited node.
      if ($nid && $nid != $node->nid) {
        form_set_error('title', t('A <a href="@page_url">page</a> with this name alredy exists.', array('@page_url' => url("node/$nid"))));
      }
    }
    $disallowed_characters = wikitools_disallowed_characters();
    if ($disallowed_characters) {
      for ($i = 0; $i < strlen($node->title); $i++) {
        if (strpos($disallowed_characters, $node->title[$i]) !== FALSE) {
          form_set_error('title', t('The character %c is not allowed in a title', array('%c' => $node->title[$i])));
          break;
        }
      }
    }
  }
}

/**
 * Implementation of hook_form_alter().
 */
function wikitools_form_alter($form_id, &$form) {
  // Check if it is a node editing form of an affected type.
  if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id) {
    if (wikitools_type_affected($form['type']['#value'])) {
      if ($form['nid']['#value']) {
        // Node is edited.
        if (wikitools_delete_protection() && !user_access('administer nodes')) {
          unset($form['delete']);
        }
        if (wikitools_move_protection() && !user_access('administer nodes')) {
          $form['title']['#disabled'] = TRUE;
        }
      }
      else {
        // Node is new.
        if (isset($_GET['edit'])) {
          $form['title']['#default_value'] = urldecode($_GET['edit']['title']);
        }
      }
    }
  }
}

/**
 * Callback of node delete action in protected mode.
 */
function wikitools_delete_protection_delete_confirm(&$node) {
  if (!wikitools_type_affected($node->type) || user_access('administer nodes')) {
    // Call original function.
    return drupal_get_form('node_delete_confirm', $node);
  }
  else {
    return drupal_access_denied();
  }
}

/**
 * Build an url to create a new node.
 * @param $type
 *   type of new node
 * @param $title
 *   title of new node
 */
function wikitools_create_url($type, $title) {
  return url("node/add/$type", 'edit[title]='. urlencode($title));
}

/**
 * Build an url to search for a title.
 * @param $title
 *   title to search for
 */
function wikitools_search_url($title) {
  return url('search/node/' . urlencode($title));
}

/**
 * Build an url to link to a page.
 * @param $title
 *   title to link to
 * @param $query
 *   an optional query string to append to the link
 */
function wikitools_wikilink_url($title, $query = NULL) {
  $drupal_path = wikitools_wikilink_drupal_path($title);
  if ($drupal_path) {
    return url($drupal_path, $query);
  }
}

/**
 * Build a Drupal path to link to a page.
 * @param $title
 *   title to link to
 * @param $query
 *   an optional query string to append to the link
 */
function wikitools_wikilink_drupal_path($title) {
  if (wikitools_treat_underscore_as_space()) {
    $title = str_replace(' ', '_', $title);
  }
  if (wikitools_treat_dash_as_space()) {
    $title = str_replace(' ', '-', $title);
  }
  if ($wiki_path = wikitools_wiki_path()) {
    return $wiki_path .'/'. urlencode($title);
  }
  elseif (wikitools_hijack_freelinking()) {
    return 'freelinking/'. urlencode($title);
  }
  else {
    // Neither wikitools nor freelinking will handle the link.
    // Try to find a node with the given name and link directly to the first match.
    $result = db_query("SELECT nid, type FROM {node} WHERE LOWER(title) = LOWER('%s')", $title);
    $found_nodes = array();
    while ($node = db_fetch_object($result)) {
      if (wikitools_type_affected($node->type)) {
        return "node/$node->nid";
      }
    }
  }
}

/*
 * Theme functions
 */

function theme_wikitools_page_found($page_name, $found_nodes) {
  $output = '<p>'. t('Multiple pages have this name:') .'</p>';
  foreach($found_nodes as $info) {
    $node = node_load($info->nid);
    $output .= node_view($node, TRUE, FALSE, FALSE);
  }
  $output .= theme('wikitools_search_notice' ,$page_name);
  if (!wikitools_enforce_unique_titles()) {
    $output .= theme('wikitools_create_notice', $page_name);
  }
  return $output;
}

function theme_wikitools_page_moved($page_name, $moved_nodes) {
  $output = '<p>'. t('The page %page_name has been moved.', array('%page_name' => $page_name)) .'</p>';
  $node = current($moved_nodes);
  $output .= '<p>'. t('The new page name is !new_name', array('!new_name' => l($node->title, "node/$node->nid"))) .'</p>';
  // Todo: show all moved pages
  $output .= theme('wikitools_search_notice' ,$page_name);
  $output .= theme('wikitools_create_notice', $page_name);
  return $output;
}

function theme_wikitools_page_does_not_exist($page_name) {
  $output = '<p>'. t('The page %page_name does not exist.', array('%page_name' => $page_name)) .'</p>';
  $output .= theme('wikitools_search_notice' ,$page_name);
  $output .= theme('wikitools_create_notice', $page_name);
  return $output;
}

function theme_wikitools_search_notice($page_name) {
  $output = '';
  if (module_exists('search') && user_access('search content') && wikitools_node_search()) {
    $output .= '<p>'. t('You can <a href="@url">search for %page_name</a>', array('@url' => wikitools_search_url($page_name), '%page_name' => $page_name)) .'</p>';
  }
  return $output;
}

function theme_wikitools_create_notice($page_name) {
  $output = '';
  $node_types = wikitools_node_types();
  if (wikitools_node_creation() && count($node_types)) {
    $create = '';
    foreach($node_types as $type) {
      $type = node_get_types('type', $type);
      if (node_access('create', $type->type)) {
        $create .= '<dt><a href="'. wikitools_create_url($type->type, $page_name) . '">'. $type->name .'</a></dt>';
        $create .= '<dd>'. filter_xss_admin($type->description) .'</dd>';
      }
    }
    if ($create) {
      $output .= '<p>'. t('You can create the page as:') .'</p>';
      $output .= '<dl>'. $create .'</dl>';
    }
  }
  return $output;
}