//WAREHUT: To enable international shipping, add this function to your functions.php file
//Make sure that this function doesn't get erased during updates.
//For any questions, please contact your customer service representative.
function get_product_customs_details( $response, $object, $request ) {

    if ( empty( $response->data ) )
        return $response;

    $products = $response->get_data();

    foreach ( $products['line_items'] as $key => $productItem ) {
        $product_id = $productItem['product_id'];
        
        // Check if product ID is valid
        if ( ! empty( $product_id ) ) {
            $product = wc_get_product( $product_id );

            // Check if product is valid
            if ( $product && ! is_wp_error( $product ) ) {
                // Add HS Codes to /orders API Requests
                $hs_code_attr = $product->get_attribute( 'hscode' );
                $hs_code = ! empty( $hs_code_attr ) ? $hs_code_attr : '';
                $response->data['line_items'][ $key ]['hs_code'] = $hs_code;

                // Add Country of Origin to /orders API Requests
                $country_of_origin_attr = $product->get_attribute( 'origin' );
                $country_of_origin = ! empty( $country_of_origin_attr ) ? $country_of_origin_attr : '';
                $response->data['line_items'][ $key ]['country_of_origin'] = $country_of_origin;

                // Add Weight to /orders API Requests
                $weight = $product->get_weight();
                $response->data['line_items'][ $key ]['weight'] = $weight;
            }
        }
    }

    return $response;
}

add_filter( "woocommerce_rest_prepare_shop_order_object", "get_product_customs_details", 10, 3 );