WWOF + WWPP — hide non-wholesale variations in REST when loading

functions.php

/**
 * Temporary: WWOF + WWPP — hide non-wholesale variations in REST when loading
 * /wc/v3/products/{id}/variations?wwof=… (parent + dropdown on order form).
 * Remove after Wholesale Order Form includes an official fix.
 */
add_filter(
	'woocommerce_rest_product_variation_object_query',
	static function ( $args, $request ) {
		if ( ! $request instanceof WP_REST_Request || ! $request->get_param( 'wwof' ) ) {
			return $args;
		}
		if ( 'yes' !== get_option( 'wwpp_settings_only_show_wholesale_products_to_wholesale_users', 'no' ) ) {
			return $args;
		}
		if ( 'edit' === $request->get_param( 'context' ) || current_user_can( 'manage_options' ) ) {
			return $args;
		}
		if ( ! function_exists( 'wc_get_product' ) || empty( $GLOBALS['wc_wholesale_prices'] ) ) {
			return $args;
		}

		global $wc_wholesale_prices;

		$registered = $wc_wholesale_prices->wwp_wholesale_roles->getAllRegisteredWholesaleRoles();
		$user_role  = $wc_wholesale_prices->wwp_wholesale_roles->getUserWholesaleRole()[0] ?? '';

		if ( ! $user_role || ! isset( $registered[ $user_role ] ) ) {
			return $args;
		}

		$product_id = isset( $request['product_id'] ) ? absint( $request['product_id'] ) : 0;
		if ( ! $product_id ) {
			return $args;
		}

		$parent = wc_get_product( $product_id );
		if ( ! $parent || ! $parent->is_type( 'variable' ) ) {
			return $args;
		}

		$filtered_children = array_map( 'absint', (array) $parent->get_children() );

		if ( ! empty( $args['post__in'] ) ) {
			$intersect = array_values(
				array_intersect(
					array_map( 'absint', (array) $args['post__in'] ),
					$filtered_children
				)
			);
			$args['post__in'] = ! empty( $intersect ) ? $intersect : array( 0 );
		} else {
			$args['post__in'] = ! empty( $filtered_children ) ? $filtered_children : array( 0 );
		}

		return $args;
	},
	110,
	2
);