WPGlobaCart - WooCommerce Cost of Goods

    protected function get_total_cost_refunded_for_item( $item, $item_id = null ) {
        global $wpdb;

        $total = null;

        if ( $item instanceof \WC_Order_Item ) {

            $total = 0;

            global $blog_id;
            $switch_to_blog =   FALSE;

            if ( $blog_id > 1 )
                {
                    $switch_to_blog =   $blog_id;
                    restore_current_blog();
                }

            $order = $item->get_order();

            if ( $switch_to_blog !== FALSE )
                switch_to_blog( $switch_to_blog );

            if ( ! empty ( $order_blog_id ) )
                restore_current_blog();

            foreach ( $order->get_refunds() as $refund ) {
                /* @var \WC_Order_Item $refunded_item */
                foreach ( $refund->get_items() as $refunded_item ) {

                    if ( absint( $refunded_item->get_meta( '_refunded_item_id' ) ) === $item->get_id() ) {
                        $total_cost = $refunded_item->get_meta( '_wc_cog_item_total_cost' );
                        $total += is_numeric( $total_cost ) ? (float) $total_cost : 0;
                    }
                }
            }

        } elseif ( $item_id ) {

            $total = $wpdb->get_var( $wpdb->prepare( "
                SELECT SUM( order_itemmeta.meta_value )
                FROM {$wpdb->prefix}woocommerce_order_itemmeta AS order_itemmeta
                WHERE order_itemmeta.meta_key = '_wc_cog_item_total_cost' AND
                order_itemmeta.order_item_id  IN (
                    SELECT order_item_id FROM {$wpdb->prefix}woocommerce_order_itemmeta as order_itemmeta2
                    WHERE order_itemmeta2.meta_value = %d AND order_itemmeta2.meta_key = '_refunded_item_id'
                )
            ", $item_id ) );
        }

        return str_replace( '-', '', (string) $total );
    }