<?php
// $Id: smart_menus.module,v 1.11 2010/09/21 05:07:48 rdeboer Exp $

/**
 * @file
 *  Adds memory to your menus and tabs so that on subsequent visits to the
 *  parent page the previously visited menu item is pre-selected for you.
 *
 *  For a quick example, after enabling the module on your site go to
 *  Administer>>Site building>>Blocks to replace your "Navigation" block with
 *  the "Smart navigation" block.
 *  Then navigate to Administer>>Site building>>Menus>>Primary links, (i.e.
 *  admin/build/menu-customize/primary-links), then click My account (/user).
 *  Clicking Administer again will now auto-expand all the way to Primary links.
 */
require_once drupal_get_path('module', 'smart_menus') .'/smart_menus.install';

define('SMART_MENUS_DEFAULT_MENU_EXCLUSIONS',
  "admin/build/modules*"); // Modules page can be slow to load

/**
 * Implementation of hook_help().
 */
function smart_menus_help($path, $arg) {
  switch ($path) {
    case 'admin/help#smart_menus':
      $s = t('Adds memory to your menus so that on subsequent visits to the parent page the previously visited menu item is pre-selected for you.');
      break;
  }
  return empty($s) ? '' : '<p>'. $s .'</p>';
}

/**
 * Implementation of hook_perm().
 */
function smart_menus_perm() {
  return array('administer Smart menus personal settings');
}

/**
 * Implementation of hook_menu().
 *
 * Define configuration options for Smart menus.
 */
function smart_menus_menu() {
  $items['admin/settings/smart_menus'] = array(
    'title' => 'Smart menus',
    'description' =>  'Configure Smart menus behaviour',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('smart_menus_admin_settings'),
    'access arguments' => array('administer site configuration'),
  );
  return $items;
}

/**
 * Menu callback for admin settings.
 */
function smart_menus_admin_settings() {
  $form['smart_menus'] = array(
    '#type' => 'fieldset',
    '#title' => t('Specify the pages on which menus should behave smartly'),
    '#collapsible' => FALSE,
  );
  $form['smart_menus']['smart_menus_include_pages'] = array(
    '#type' => 'textarea',
    '#title' => t('Pages to include'),
    '#default_value' => variable_get('smart_menus_include_pages', '*'),
    '#description' => t("Enter Drupal menu paths, one per line. '*' is the wildcard character. Examples are %node-wildcard for normal content pages and %admin-wildcard for the administration pages.",
      array('%node-wildcard' => 'node/*', '%admin-wildcard' => 'admin/*')),
  );
  $form['smart_menus']['smart_menus_exclude_pages'] = array(
    '#type' => 'textarea',
    '#title' => t('Pages to exclude from the collection specified above'),
    '#default_value' => variable_get('smart_menus_exclude_pages', SMART_MENUS_DEFAULT_MENU_EXCLUSIONS),
    '#description' => t("Enter Drupal menu paths, one per line. '*' is the wildcard character. An example is %admin-wildcard for the module configuration page(s), which can be slow to load. Use URL aliases where they exist, instead of %node. %front is the front page.",
      array('%admin-wildcard' => 'admin/build/modules/*', '%node' => 'node/123', '%front' => '<front>'))
  );
  $form['smart_menus_depth'] = array(
    '#type' => 'textfield',
    '#title' => t('Smart menus auto-expansion depth'),
    '#default_value' => (int)variable_get('smart_menus_depth', 9),
    '#description' => t('The maximum number of menu levels to which to auto-expand any submenu. This applies to anonymous users. Authenticated users may override this setting. Use 0 to revert to the static menu behaviour of core.'),
  );
  $form['smart_menus_tabbed_content'] = array(
    '#type' => 'checkbox',
    '#title' => t('Smart menus for tabbed content'),
    '#default_value' => variable_get('smart_menus_tabbed_content', TRUE),
    '#description' => t('Core Drupal behaviour is to collapse the associated menu whenever a content tab (Edit, Revisions, Track...) is clicked. When this option is ticked Smart menus auto-expand to highlight the menu item the tab belongs to.'),
  );
  $form['smart_menus_active_trail'] = array(
    '#type' => 'checkbox',
    '#title' => t('Highlight active menu trail'),
    '#default_value' => variable_get('smart_menus_active_trail', FALSE),
    '#description' => t('Highlight the entire active menu trail, not just the bottom item. The latter is core behaviour.'),
  );
  $form['smart_menus_debug'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enable debug info'),
    '#default_value' => variable_get('smart_menus_debug', FALSE),
    '#description' => t('Debug info is visible only to a logged-in administrator (uid=1).'),
  );
  return system_settings_form($form);
}

/**
 * Implementation of hook_form_FORMID_alter().
 */
function smart_menus_form_smart_menus_admin_settings_alter(&$form, &$form_state) {
  _sm_debug_info(t('Clearing menu cache.'));
  menu_cache_clear_all();
}

/**
 * Implementation of hook_user().
 */
function smart_menus_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {

    case 'categories':
      // Get here once when module is first enabled.
      return array(array(
        'name' => 'smart menus',
        'title' => t('Smart menus'),
        'access callback' => 'user_access',
        'access arguments' => array('administer Smart menus personal settings'),
        'weight' => 10, // same as Smart tabs
      ));

    case 'form':
      if ($category == 'smart menus') {
        return _smart_menus_user_profile_form($edit);
      }
      break;

    case 'validate':
      $depth = $edit['profile_smart_menus_depth'];
      if ((!empty($depth) && !is_numeric($depth)) || $depth < 0 || $depth > 9) {
        form_set_error('profile_smart_menus_depth', t('Auto-expansion depth must be a single digit or left blank'));
      }
      break;
  }
}

/**
 * Helper function to add Smart menus personal settings form to the user
 * profile, i.e. 'My account' page (Edit tab).
 */
function _smart_menus_user_profile_form($edit) {
  $form = array();
  $form['smart_menus'] = array(
    '#type' => 'fieldset',
    '#title' => t('Smart menus settings'),
    '#collapsible' => FALSE,
    '#collapsed' => FALSE,
  );
  $form['smart_menus']['profile_smart_menus_depth'] = array(
    '#type' => 'textfield',
    '#title' => t('Smart menus auto-expansion depth'),
    '#default_value' => is_numeric($edit['profile_smart_menus_depth']) ? $edit['profile_smart_menus_depth'] : variable_get('smart_menus_depth', 9),
    '#description' => t('The maximum number of menu levels to which to auto-expand any (sub)menu. Leave blank to accept the default as set by the system administrtor. Use 0 to revert to the static menu behaviour of core.')
  );
  $form['smart_menus']['profile_smart_menus_disable_tabbed_content'] = array(
    '#type' => 'checkbox',
    '#title' => t('Disable Smart menus for tabbed content'),
    '#default_value' => isset($edit['profile_smart_menus_disable_tabbed_content']) ? $edit['profile_smart_menus_disable_tabbed_content'] : !variable_get('smart_menus_tabbed_content', TRUE),
    '#description' => t('Unless disabled here, your content menus will auto-expand to highlight the menu item belonging to the selected content tab, i.e. Edit, Revisions, Track etc.).')
  );
  $form['smart_menus']['profile_smart_menus_active_trail'] = array(
    '#type' => 'checkbox',
    '#title' => t('Highlight active menu trail'),
    '#default_value' => isset($edit['profile_smart_menus_active_trail']) ? $edit['profile_smart_menus_active_trail'] : variable_get('smart_menus_active_trail', FALSE),
    '#description' => t('Highlight the entire active menu trail, not just the bottom item.')
  );
  return $form;
}

/**
 * Implementation of hook_block().
 *
 * Smart version of the navigation menu block.
 */
function smart_menus_block($op = 'list', $delta = 0, $edit = array()) {
  global $user;

  switch ($op) {
    case 'list':
      // Set up the defaults for the Site configuration>>Blocks page.
      // Return an array of 4 blocks and their default values.
      $blocks[0]['info'] = t('Smart navigation');
      $blocks[1]['info'] = t('Smart primary links');
      $blocks[2]['info'] = t('Smart secondary links');
      $blocks[3]['info'] = t('Smart custom links');
      foreach ($blocks as $i => $block) {
        $blocks[$i]['cache'] = BLOCK_NO_CACHE;
      }
      return $blocks;

    case 'configure':
      $form["smart_menus_block_invisible_$delta"] = array(
        '#type' => 'checkbox',
        '#title' => t('Make this block invisible. Let Smart menus do its magic without displaying the menu, as I use my own menu renderer.'),
        '#default_value' => variable_get("smart_menus_block_invisible_$delta", FALSE),
        '#description' => t('Tick this to make your <strong>Administration menu</strong>, <strong>SimpleMenu</strong>, <strong>Nice Menus</strong>, <strong>Menu block</strong> or <strong>JQuery menu</strong> Smart.')
      );
      if ($delta > 2) {
        $form['smart_menus_custom_links_name'] = array(
          '#type' => 'textfield',
          '#title' => t('Smart menus custom links menu name'),
          '#default_value' => variable_get('smart_menus_custom_links_name', _smart_menus_find_default_custom_links_name()),
          '#description' => t('Machine name of the custom links menu that should behave smartly. This is the name you entered when you created the menu at %link, prefixed with "menu-".', array('%link' => 'Administer >> Site building >> Menus'))
        );
      }
      return $form;

    case 'save':
      variable_set("smart_menus_block_invisible_$delta", $edit["smart_menus_block_invisible_$delta"]);
      if ($delta > 2) {
        variable_set('smart_menus_custom_links_name', $edit['smart_menus_custom_links_name']);
      }
      return;

    case 'view':
      $block = array();
      switch ($delta) {
        case 0:
          $block['subject'] = $user->uid ? check_plain($user->name) : t('Navigation');
          $menu_name = 'navigation';
          break;

        case 1:
          $block['subject'] = t('Primary links');
          $menu_name = 'primary-links';
          break;

        case 2:
          $block['subject'] = t('Secondary links');
          $menu_name = 'secondary-links';
          break;

        case 3:
          $block['subject'] = t('Custom links');
          $menu_name = variable_get('smart_menus_custom_links_name', _smart_menus_find_default_custom_links_name());
          break;
      }
      if (variable_get("smart_menus_block_invisible_$delta", FALSE)) {
        // Do the auto-expansion and memory magic leaving rendering of the menu
        // to another module. Do not place any content in the $block.
        _smart_menus_tree_page_data($menu_name, FALSE);
      }
      elseif ($tree_menu = _smart_menus_theme_menu_tree($menu_name)) {
        $block['content'] = $tree_menu;
      }
      return $block;
  }
}

function _smart_menus_find_default_custom_links_name() {
  $sql = "SELECT menu_name FROM {menu_links} WHERE menu_name LIKE 'menu-%';";
  return db_result(db_query($sql));
}

/**
 * Render a menu tree based on the current path.
 *
 * @param $menu_name
 *   The name of the menu.
 * @return
 *   The rendered HTML of that menu on the current page.
 */
function _smart_menus_theme_menu_tree($menu_name = 'navigation') {
  static $themed_menu = array();
  if (!isset($themed_menu[$menu_name])) {
    $themed_menu[$menu_name] = menu_tree_output(_smart_menus_tree_page_data($menu_name));
  }
  return $themed_menu[$menu_name];
}

/**
 * Get the data structure representing a named menu tree, based on the current
 * page AND information in the session about recently visited menu items.
 * This info tells us which menus to display expanded.
 *
 * The tree order is maintained by storing each parent in an individual
 * field, see http://drupal.org/node/141866 for more.
 *
 * @param $menu_name
 *   The named menu links to return
 * @param $assemble_menu_tree
 *   Defaults to TRUE. Set this to FALSE if you want to auto-expansion and
 *   memory magic to happen, but intend to render the menu through elsewhere.
 * @return
 *   An array of menu links, in the order they should be rendered. The array
 *   is a list of associative arrays -- these have two keys, 'link' and 'below'.
 *   'link' is a menu item, ready for theming as a link.
 *   'below' represents the submenu below the link if there is one, and it is a
 *   subtree that has the same structure described for the top-level array.
 *   See menu.inc/menu_tree_output() for the themed rendering of the array
 *   returned.
 */
function _smart_menus_tree_page_data($menu_name = 'navigation', $assemble_menu_tree = TRUE) {
  static $tree;
  // Load the menu item corresponding to the current page.
  if ($item = menu_get_item()) {
    $clicked_href = $item['href'];
    $uri = arg();
    // Generate a cache ID (cid) specific for this page.
    // Core version of menu_tree_page_data() is wasteful w.r.t tabbed content
    // as node/123/edit belongs to the same menu item as node/123/revisions
    // so doesn't need to be cached twice or more.
    // Note: this also neatly implements Smart menus for tabbed content feature
    // except for the highlighting. @TODO revisit.
    $cid = 'links:'. $menu_name .':page-cid:'
      . (/* _smart_menus_is_tabbed_content_page($uri) */ FALSE ? 'node/'. $uri[1] : $clicked_href)
      .':'. (int)$item['access'];

    if (!isset($tree[$cid])) {
      $use_cache = TRUE; // always..., until someone feels otherwise...
      if ($use_cache && $assemble_menu_tree) {
        $cache = cache_get($cid, 'cache_menu');
        if ($cache && isset($cache->data)) {
          $cache = cache_get($cache->data, 'cache_menu');
          if ($cache && isset($cache->data)) {
            //_sm_debug_info(t('Retrieving submenu %cid from cache', array('%cid' => $cid)));
            $data = $cache->data;
          }
        }
      }
      // Check whether a menu link exists that corresponds to the current path.
      $parents = _smart_menus_retrieve_mlid_trail($menu_name, $item);
      _smart_menus_auto_expand_to_previously_active_child($menu_name, $clicked_href, $parents);

      // See if this was a click on a the tabbed content page, e.g. the Edit,
      // Revisions, Track tabs above node/% pages.
      // If so determine the parent trail and expand the associated menu.
      if (_smart_menus_is_tabbed_content_page($uri) && _smart_menus_get_user_tabbed_content_expansion()) {
        if ($assemble_menu_tree) {
          $parents = _smart_menus_expand_submenu($menu_name, 'node/'. $uri[1]);
        }
      }
      else {
        _smart_menus_remember_active_trail($menu_name, $parents, $clicked_href);
      }

      if (!$assemble_menu_tree) {
        return;
      }

      // If the tree data was not in the cache, $data will be NULL.
      if (!isset($data)) {
        _sm_debug_info(t('Submenu %cid is not in cache - loading it from {menu_links}.', array('%cid' => $cid)));
        if ($item['access']) {
          // Set up the placeholders for the SQL: one '%d' for every plid
          $placeholders = implode(', ', array_fill(0, count($parents), '%d'));
          // See if any of the menus are configured to be always expanded.
          // The 'menu_expanded' var is non-empty if there's at least one
          // submenu configured to be rendered expanded, as per the
          // admin/build/menu/navigation page.
          $args = $parents;
          $expanded_menu_names = variable_get('menu_expanded', array());
          if (in_array($menu_name, $expanded_menu_names)) {
            // Collect all the links set to be expanded, and then add all of
            // their children too
            do {
              $sql = "SELECT mlid FROM {menu_links} WHERE menu_name = '%s' AND expanded = 1 AND has_children = 1"
                ." AND plid IN (". $placeholders .') AND mlid NOT IN ('. $placeholders .')';
              $result = db_query($sql, array_merge(array($menu_name), $args, $args));
              $num_rows = FALSE;
              while ($item = db_fetch_array($result)) {
                $args[] = $item['mlid'];
                $num_rows = TRUE;
              }
              $placeholders = implode(', ', array_fill(0, count($args), '%d'));
            } while ($num_rows);
          }
          array_unshift($args, $menu_name);
        } // $item['access']
        else {
          // No access: show only the top-level menu items when access is denied.
          $args = array($menu_name, '0');
          $placeholders = '%d';
          $parents = array();
        }
        // Select the links from the table, and recursively build the tree. We
        // LEFT JOIN since there is no match in {menu_router} for an external
        // link.
        // $parents is passed in to apply CSS style class for the active trail.
        $data['tree'] = menu_tree_data(db_query("
          SELECT m.load_functions, m.to_arg_functions, m.access_callback, m.access_arguments, m.page_callback, m.page_arguments, m.title, m.title_callback, m.title_arguments, m.type, m.description, ml.*
          FROM {menu_links} ml LEFT JOIN {menu_router} m ON m.path = ml.router_path
          WHERE ml.menu_name = '%s' AND ml.plid IN (". $placeholders .")
          ORDER BY p1 ASC, p2 ASC, p3 ASC, p4 ASC, p5 ASC, p6 ASC, p7 ASC, p8 ASC, p9 ASC", $args),
          $parents);
        $data['node_links'] = array();

        menu_tree_collect_node_links($data['tree'], $data['node_links']);

        if ($use_cache) {
          $tree_cid = _menu_tree_cid($menu_name, $data);
          if (!cache_get($tree_cid, 'cache_menu')) {
            _sm_debug_info(t('Putting menu in cache %tree_cid', array('%tree_cid' => $tree_cid)));
            cache_set($tree_cid, $data, 'cache_menu');
          }
          // Cache the cid of the shared data using the page-specific cid.
          // Multiple cids (URLs) may point to the same $tree_cid.
          cache_set($cid, $tree_cid, 'cache_menu');
        }
      } // !isset($data)

      // Check access for the current user to each item in the tree.
      menu_tree_check_access($data['tree'], $data['node_links']);

      // Core doesn't highlight menu item belonging to the selected content tab
      if (count($parents) > 1) {
        $clicked_mlid = $parents[count($parents) - 2];
        _smart_menus_markup_active_trail($data['tree'],
          _smart_menus_get_user_show_active_trail() ? array_slice($parents, 0, -1) : array($clicked_mlid));
      }

      $tree[$cid] = $data['tree'];
    } // isset($tree[$cid])
    return $tree[$cid];
  } // $item != NULL
  return array();
}

function _smart_menus_retrieve_mlid_trail($menu_name, $item) {
  $args = array($menu_name, $item['href']);
  $placeholders = "'%s'";
  if (drupal_is_front_page()) {
    $args[] = '<front>';
    $placeholders .= ", '%s'";
  }
  $parents = db_fetch_array(db_query("SELECT p1, p2, p3, p4, p5, p6, p7, p8 FROM {menu_links} WHERE menu_name = '%s' AND link_path IN (". $placeholders .")", $args));
  if (empty($parents)) {
    // If no parent exist, we may be on a local task aka tab.
    // Use the path to the tab root as the active trail.
    $parents = db_fetch_array(db_query("SELECT p1, p2, p3, p4, p5, p6, p7, p8 FROM {menu_links} WHERE menu_name = '%s' AND link_path = '%s'", $menu_name, $item['tab_root']));
  }
  // We always want all the top-level links with plid == 0.
  $parents[] = 0;
  // Use array_values() so that the indices are numeric for array_merge().
  return array_unique(array_values($parents));
}

function _smart_menus_auto_expand_to_previously_active_child($menu_name, $clicked_href, $parents) {
  if (count($parents) <= 1) {
    // Click wasn't on this menu, will be rendered unexpanded.
    return;
  }
  $current_trail = implode('/', array_slice($parents, 0, -1)) .'/';
  $last_active_trail = $_SESSION[$menu_name .'-active-trail'];
  $_SESSION[$menu_name .'-active-trail'] = $current_trail;
  if ($last_active_trail != $current_trail) {
    $clicked_alias = drupal_get_path_alias($clicked_href);
    $clicked_mlid = $parents[count($parents) - 2];
    // See if the last_active_trail starts with the current_trail
    $pos = strpos($last_active_trail, $current_trail);
    if ($pos === FALSE || $pos > 0) {
      _smart_menus_if_not_excluded_goto_previously_active_menu_child($menu_name, $clicked_alias, $clicked_mlid);
    }
    else {
      _sm_debug_info(t('@menu_name menu %clicked_menu_item: menu item %menu_id_trail backtracks on active menu trail %last_menu_id_trail -- not auto-expanding this submenu.', array(
        '@menu_name' => $menu_name,
        '%clicked_menu_item' => $clicked_alias,
        '%menu_id_trail' => $current_trail,
        '%last_menu_id_trail' => $last_active_trail)));
      // Am in two minds about whether to forget child or not
      unset($_SESSION[$menu_name .'-active-menus'][$clicked_mlid]);
    }
  }
  else {
    // We get here when someone clicks the same menu item twice, when Smart
    // tabs auto-selects a child tab or when the Smart navigation and Smart
    // primary-links blocks are both installed and the user clicks two
    // (different) primary links in succession. This is a side-effect of the
    // primary links being children of /node (mlid=7 in menu_links table).
    // Similar behaviour for /admin (mlid=2) and /node (mlid=3).
    // All of this is harmless and can be ignored.
    // _sm_debug_info(t('Revisiting menu item %menu_id_trail, %clicked_menu_item.', array(
    //   '%menu_id_trail' => $current_trail,
    //   '%clicked_menu_item' => $clicked_href)));
  }
}

function _smart_menus_if_not_excluded_goto_previously_active_menu_child($menu_name, $clicked_alias, $clicked_mlid) {
  $max_depth = $_SESSION['smart_menu_stop_expanding'] ? 0 : _smart_menus_get_user_smart_menu_depth();;
  $depth = 1;
  $mlid = $clicked_mlid;
  while ($depth < $max_depth && ($child = $_SESSION[$menu_name .'-active-menus'][$mlid]['child']) > 0) {
    $mlid = $child;
    $depth++;
  }
  if ($depth > 1) { // the clicked menu item has a previously active child

    $include_items = variable_get('smart_menus_include_pages', '*');
    $exclude_items = variable_get('smart_menus_exclude_pages', SMART_MENUS_DEFAULT_MENU_EXCLUSIONS);
    $is_included = drupal_match_path($clicked_alias, $include_items);
    $is_excluded = drupal_match_path($clicked_alias, $exclude_items);

    if ($is_included && !$is_excluded) {
      $expanded_path = drupal_get_path_alias($_SESSION[$menu_name .'-active-menus'][$mlid]['href']);
      if (drupal_match_path($expanded_path, $exclude_items)) {
        _sm_debug_info(t('Not auto-expanding to %path as it is on the Smart menus exclusion list.', array('%path' => $expanded_path)));
      }
      elseif (!empty($expanded_path)) {
        // Go to the previously active item. This will load the page content
        // and then call _smart_menus_tree_page_data again.
        _sm_debug_info(t('Auto-expanding !count level(s) to previously selected menu item %path.',
          array('!count' => $depth - 1, '%path' => $expanded_path)));
        $_SESSION['smart_menu_stop_expanding'] = TRUE;
        drupal_goto($expanded_path);
      }
    }
    else{
      _sm_debug_info(t('Submenu %path is excluded from Smart menus expansion.', array('%path' => $clicked_alias)));
    }
  }
  unset($_SESSION['smart_menu_stop_expanding']);
}

function _smart_menus_expand_submenu($menu_name, $href) {
  $parents = _smart_menus_find_parents($menu_name, $href);
  _sm_debug_info(t('@menu_name menu trail belonging to %page is %menu_trail', array(
    '@menu_name' => $menu_name,
    '%page' => $href,
    '%menu_trail' => implode('/', $parents))));
  $parents[] = 0; // Want top menu, apparently...
  return $parents;
}

/**
 * See if this was a click on a content tab (Edit, Track, etc), ie. a URI of
 * the form 'node/%/<op>', where <op> is one of edit, track, revisions, etc.
 * @param $uri
 * @return bool
 */
function _smart_menus_is_tabbed_content_page($uri) {
  return $uri[0] == 'node' && is_numeric($uri[1]) && !empty($uri[2]);
}

function _smart_menus_markup_active_trail(&$tree, $parents) {
  foreach ($tree as &$menu) {
    if (in_array($menu['link']['mlid'], $parents)) {
      $menu['link']['localized_options']['attributes']['class'] = 'active';
    }
    if (!empty($menu['below'])) {
      _smart_menus_markup_active_trail($menu['below'], $parents);
    }
  }
}

/**
 * Note: the currently selected tabbed page parent tends to come up
 * as $_SESSION[navigation-active-menus][7]['href'], where
 * 7 equals $_SESSION[navigation-active-trail] (without the '/')
 *
 * @param $menu_name
 * @param $href
 * @return mlid
 */
function _smart_menus_find_parents($menu_name, $href) {
  $parent_mlids = array();
  if ($mlid = _smart_menus_find_mlid_by_href($menu_name, $href)) {
    $parent_mlids[] = $mlid;
    while ($mlid = _smart_menus_find_parent_mlid($menu_name, $mlid)) {
      $parent_mlids[] = $mlid;
    }
  }
  return array_reverse($parent_mlids);
}

function _smart_menus_find_mlid_by_href($menu_name, $href) {
  if (isset($_SESSION[$menu_name .'-active-menus'])) {
    // Find a previously visited menu item with the requested href
    foreach ($_SESSION[$menu_name .'-active-menus'] as $mlid => $item) {
      if ($item['href'] == $href) {
        return $mlid;
      }
    }
  }
}

function _smart_menus_find_parent_mlid($menu_name, $mlid) {
  foreach ($_SESSION[$menu_name .'-active-menus'] as $plid => $item) {
    if (isset($item['child']) && $item['child'] == $mlid) {
      return $plid;
    }
  }
}

function _smart_menus_remember_active_trail($menu_name, $parents, $clicked_href) {
  // $parents = explode('/', $_SESSION[$menu_name .'-active-trail']);
  // When menu is clicked $parents has at least 2 elements, the second being 0
  for ($i = 0; $i < count($parents) - 1; $i++) {
    if (!isset($parents[$i + 1]) || $parents[$i + 1] <= 0) {
      // Last one has no child, but is used to store href
      $_SESSION[$menu_name .'-active-menus'][$parents[$i]]['href'] = $clicked_href;
      break;
    }
    $_SESSION[$menu_name .'-active-menus'][$parents[$i]]['child'] = $parents[$i + 1];
  }
  //_sm_debug_info("\$_SESSION[$menu_name" .'-active-trail]: '. $_SESSION[$menu_name .'-active-trail']);
  //_sm_debug_info("\$_SESSION[$menu_name" .'-active-menus]: '. print_r($_SESSION[$menu_name .'-active-menus'], TRUE));
}

function _smart_menus_get_user_smart_menu_depth() {
  global $user;
  $smart_menus_depth = $user->profile_smart_menus_depth;
  if (!is_numeric($smart_menus_depth)) { // e.g. Anonymous user
    // Fall back to the global default as configured by the administrator
    $smart_menus_depth = variable_get('smart_menus_depth', 9);
  }
  return (int)$smart_menus_depth;
}

function _smart_menus_get_user_tabbed_content_expansion() {
  global $user;
  $disabled_tabbed_content = $user->profile_smart_menus_disable_tabbed_content;
  return isset($disabled_tabbed_content) ? !$disabled_tabbed_content : variable_get('smart_menus_tabbed_content', TRUE);
}

function _smart_menus_get_user_show_active_trail() {
  global $user;
  $show_active_trail = $user->profile_smart_menus_active_trail;
  return isset($show_active_trail) ? (bool)$show_active_trail : variable_get('smart_menus_active_trail', FALSE);
}

function _sm_debug_info($message) {
  global $user;
  if ($user->uid == 1 && variable_get('smart_menus_debug', FALSE)) {
    drupal_set_message("Smart menus - $message", 'warning');
  }
}

/*
function _smart_menus_get_path_by_mlid($mlid) {
  return db_result(db_query("SELECT link_path FROM {menu_links} WHERE mlid = %d", $mlid));
}

function _smart_menus_get_menu_item($path) {
  return db_fetch_array(db_query("SELECT * FROM {menu_router} WHERE path = '%s'", $path));
}
 */