if( ! function_exists( 'videotube_child_reorder_videos' ) ){

    /**
     * Reoder videos based on viewed
     * @param $query
     */

    function videotube_child_reorder_videos( $query ) {

        $order = isset( $_REQUEST['order_post'] ) ? trim( $_REQUEST['order_post'] ) : null;

        if( $query->is_home() ||  $query->is_search || is_tax() || is_archive() && !is_admin() ){

            if( $query->is_main_query() ){
                if( empty( $order ) || $order == 'viewed' ){
                    $query->set( 'meta_key','count_viewed' );
                    $query->set( 'orderby', 'meta_value_num' );
                }
            }
        }

    }

    add_action('pre_get_posts', 'videotube_child_reorder_videos');
}