<?php
if (!defined('ABSPATH')) {
  die('-1');
}

class QuadMenuWalker extends Walker_Nav_Menu {

  var $item_stack = array();
  var $current_umitem;
  var $auto_child = '';

  function __construct() {
    
  }

  function display_element($element, &$children_elements, $max_depth, $depth, $args, &$output) {

    if (!$element)
      return;

    $id_field = $this->db_fields['id'];

    $has_children = !empty($children_elements[$element->{$id_field}]);

    if (isset($args[0]) && is_array($args[0])) {
      $args[0]['has_children'] = $has_children;
    }

    $cb_args = array_merge(array(&$output, $element, $depth), $args);

    $id = $element->{$id_field};  // Moved up

    if (!class_exists($umitem_obect_class = apply_filters('quadmenu_item_object_class', 'QuadMenuItemDefault', $element, $id, $this->auto_child))) {
      $umitem_obect_class = 'QuadMenuItemDefault';
    }

    $umitem = new $umitem_obect_class($output, $element, $depth, $cb_args[3], $id, $this, $has_children, $children_elements); //The $args that get passed to start_el are $cb[3] -- i.e. the 4the element in the array merged above

    $this->push_item($umitem);

    call_user_func_array(array($this, 'start_el'), $cb_args);

    // descend only when the depth is right and there are childrens for this element
    if (($max_depth == 0 || $max_depth > $depth + 1 ) && isset($children_elements[$id])) {

      foreach ($children_elements[$id] as $child) {

        if (!isset($newlevel)) {
          $newlevel = true;
          //start the child delimiter
          $cb_args = array_merge(array(&$output, $depth), $args);
          call_user_func_array(array($this, 'start_lvl'), $cb_args);
        }
        $this->display_element($child, $children_elements, $max_depth, $depth + 1, $args, $output);
      }

      //Unset this item's children elements
      unset($children_elements[$id]); //TODO!!!
    }

    if (isset($newlevel) && $newlevel) {
      //end the child delimiter
      $cb_args = array_merge(array(&$output, $depth), $args);
      call_user_func_array(array($this, 'end_lvl'), $cb_args);
    }


    $cb_args = array_merge(array(&$output, $element, $depth), $args);

    call_user_func_array(array($this, 'end_el'), $cb_args);
  }

  function start_lvl(&$output, $depth = 0, $args = array()) {
    //$indent = str_repeat("\t", $depth);
    $this->current_umitem->start_lvl();
  }

  function end_lvl(&$output, $depth = 0, $args = array()) {
    //$indent = str_repeat("\t", $depth);
    $this->current_umitem->end_lvl();
  }

  function start_el(&$output, $item, $depth = 0, $args = array(), $id = 0) {

    $this->current_umitem->start_el();
  }

  function end_el(&$output, $item, $depth = 0, $args = array()) {
    $this->current_umitem->end_el();
    $this->pop_item();
  }

  function push_item($umitem) {
    $this->item_stack[] = $umitem;
    $this->current_umitem = $umitem;
  }

  function pop_item() {
    $umitem = array_pop($this->item_stack);
    $this->current_umitem = $this->current_item();
  }

  function current_item() {
    return end($this->item_stack);
  }

  public static function fallback($args) {

    global $_wp_registered_nav_menus;

    if (!current_user_can('manage_options'))
      return;

    extract($args);

    ob_start();
    ?>
    <li class="quadmenu-item quadmenu-item-object-custom quadmenu-item-level-0 quadmenu-item-type-default quadmenu-has-title quadmenu-has-icon quadmenu-has-link">
      <a title="<?php printf(esc_html__('Add a menu to %1$s', 'quadmenu'), $_wp_registered_nav_menus[$theme_location]); ?>" href="<?php echo admin_url('nav-menus.php'); ?>">
        <span class="quadmenu-item-content">
          <span class="quadmenu-text"><?php printf(esc_html__('Add a menu to %1$s', 'quadmenu'), $_wp_registered_nav_menus[$theme_location]); ?></span>
        </span>
      </a>
    </li>
    <li class="quadmenu-item quadmenu-item-object-custom quadmenu-item-level-0 quadmenu-item-type-default quadmenu-has-title quadmenu-has-icon quadmenu-has-link">
      <a title="<?php esc_html_e('Documentation', 'quadmenu'); ?>" href="<?php echo esc_url(QUADMENU_DOCUMENTATION_URL); ?>">
        <span class="quadmenu-item-content">
          <span class="quadmenu-text"><?php esc_html_e('Documentation', 'quadmenu'); ?></span>
        </span>
      </a>
    </li>
    <li class="quadmenu-item quadmenu-item-object-custom quadmenu-item-level-0 quadmenu-item-type-default quadmenu-has-title quadmenu-has-icon quadmenu-has-link">
      <a title="<?php esc_html_e('Demo', 'quadmenu'); ?>" href="<?php echo esc_url(QUADMENU_DEMO_URL); ?>">
        <span class="quadmenu-item-content">
          <span class="quadmenu-text"><?php esc_html_e('Demo', 'quadmenu'); ?></span>
        </span>
      </a>
    </li>
    <?php
    $menu = ob_get_clean();

    $nav_menu = sprintf($items_wrap, esc_attr($menu_id), esc_attr($menu_class), $menu);

    return quadmenu_layout($nav_menu, (object) $args);
  }

}