class RulesUICategory

class RulesUICategory {
    
    /**
     * Gets info about all available categories, or about a specific category.
     *
     * @return array
     */
    public static function getInfo($category = NULL) {
        $data = rules_fetch_data('category_info');
        if (isset($category)) {
            return $data[$category];
        }
        return $data;
    }
    
    /**
     * Returns a group label, e.g. as usable for opt-groups in a select list.
     *
     * @param array $item_info
     *   The info-array of an item, e.g. an entry of hook_rules_action_info().
     * @param bool $in_category
     *   (optional) Whether group labels for grouping inside a category should be
     *   return. Defaults to FALSE.
     *
     * @return string|bool
     *   The group label to use, or FALSE if none can be found.
     */
    public static function getItemGroup($item_info, $in_category = FALSE) {
        if (isset($item_info['category']) && !$in_category) {
            return self::getCategory($item_info, 'label');
        }
        elseif (!empty($item_info['group'])) {
            return $item_info['group'];
        }
        return FALSE;
    }
    
    /**
     * Gets the category for the given item info array.
     *
     * @param array $item_info
     *   The info-array of an item, e.g. an entry of hook_rules_action_info().
     * @param string|null $key
     *   (optional) The key of the category info to return, e.g. 'label'. If none
     *   is given the whole info array is returned.
     *
     * @return array|mixed|false
     *   Either the whole category info array or the value of the given key. If
     *   no category can be found, FALSE is returned.
     */
    public static function getCategory($item_info, $key = NULL) {
        if (isset($item_info['category'])) {
            $info = self::getInfo($item_info['category']);
            return isset($key) ? $info[$key] : $info;
        }
        return FALSE;
    }
    
    /**
     * Returns an array of options to use with a select.
     *
     * Returns an array of options to use with a selectfor the items specified
     * in the given hook.
     *
     * @param string $item_type
     *   The item type to get options for. One of 'data', 'event', 'condition' and
     *   'action'.
     * @param array|null $items
     *   (optional) An array of items to restrict the options to.
     *
     * @return array
     *   An array of options.
     */
    public static function getOptions($item_type, $items = NULL) {
        $sorted_data = array();
        $ungrouped = array();
        $data = $items ? $items : rules_fetch_data($item_type . '_info');
        foreach ($data as $name => $info) {
            // Verify the current user has access to use it.
            if (!user_access('bypass rules access') && !empty($info['access callback']) && !call_user_func($info['access callback'], $item_type, $name)) {
                continue;
            }
            if ($group = RulesUICategory::getItemGroup($info)) {
                $sorted_data[drupal_ucfirst($group)][$name] = drupal_ucfirst($info['label']);
            }
            else {
                $ungrouped[$name] = drupal_ucfirst($info['label']);
            }
        }
        asort($ungrouped);
        foreach ($sorted_data as $key => $choices) {
            asort($choices);
            $sorted_data[$key] = $choices;
        }
        // Sort the grouped data by category weights, defaulting to weight 0 for
        // groups without a respective category.
        $sorted_groups = array();
        foreach (array_keys($sorted_data) as $label) {
            $sorted_groups[$label] = array(
                'weight' => 0,
                'label' => $label,
            );
        }
        // Add in category weights.
        foreach (RulesUICategory::getInfo() as $info) {
            if (isset($sorted_groups[$info['label']])) {
                $sorted_groups[$info['label']] = $info;
            }
        }
        uasort($sorted_groups, '_rules_ui_sort_categories');
        // Now replace weights with group content.
        foreach ($sorted_groups as $group => $weight) {
            $sorted_groups[$group] = $sorted_data[$group];
        }
        return $ungrouped + $sorted_groups;
    }

}