function get_admin_page_parent( $parent = '' ) {
  global $parent_file, $menu, $submenu, $pagenow, $typenow,
    $plugin_page, $_wp_real_parent_file, $_wp_menu_nopriv, $_wp_submenu_nopriv;

  if ( ! empty( $parent ) && 'admin.php' !== $parent ) {
    if ( isset( $_wp_real_parent_file[ $parent ] ) ) {
      $parent = $_wp_real_parent_file[ $parent ];
    }

    return $parent;
  }

  if ( 'admin.php' === $pagenow && isset( $plugin_page ) ) {
    foreach ( (array) $menu as $parent_menu ) {
      if ( $parent_menu[2] === $plugin_page ) {
        $parent_file = $plugin_page;

        if ( isset( $_wp_real_parent_file[ $parent_file ] ) ) {
          $parent_file = $_wp_real_parent_file[ $parent_file ];
        }

        return $parent_file;
      }
    }
    if ( isset( $_wp_menu_nopriv[ $plugin_page ] ) ) {
      $parent_file = $plugin_page;

      if ( isset( $_wp_real_parent_file[ $parent_file ] ) ) {
          $parent_file = $_wp_real_parent_file[ $parent_file ];
      }

      return $parent_file;
    }
  }

  if ( isset( $plugin_page ) && isset( $_wp_submenu_nopriv[ $pagenow ][ $plugin_page ] ) ) {
    $parent_file = $pagenow;

    if ( isset( $_wp_real_parent_file[ $parent_file ] ) ) {
      $parent_file = $_wp_real_parent_file[ $parent_file ];
    }

    return $parent_file;
  }

  foreach ( array_keys( (array) $submenu ) as $parent ) {
    foreach ( $submenu[ $parent ] as $submenu_array ) {
      if ( isset( $_wp_real_parent_file[ $parent ] ) ) {
        $parent = $_wp_real_parent_file[ $parent ];
      }

      if ( ! empty( $typenow ) && "$pagenow?post_type=$typenow" === $submenu_array[2] ) {
        $parent_file = $parent;
        return $parent;
      } elseif ( empty( $typenow ) && $pagenow === $submenu_array[2]
        && ( empty( $parent_file ) || false === strpos( $parent_file, '?' ) )
      ) {
        $parent_file = $parent;
        return $parent;
      } elseif ( isset( $plugin_page ) && $plugin_page === $submenu_array[2] ) {
        $parent_file = $parent;
        return $parent;
      }
    }
  }

  if ( empty( $parent_file ) ) {
    $parent_file = '';
  }
  return '';
}