* Determine whether a product deletion should take place.
	 *
	 * @since 5.4.0
	 *
	 * @param bool|null $delete Whether to go forward with deletion.
	 * @param WP_Post   $post   Post object.
	 * @return bool|null
	 */
	public static function maybe_prevent_product_deletion( $delete, $post ) {

		if ( ! in_array( get_post_type( $post ), array( 'course', 'llms_membership' ), true ) ) {
			return $delete;
		}

		$product = llms_get_product( $post );

		if ( empty( $product ) || ! $product->has_active_subscriptions() ) {
			return $delete;
		}

		// If performing the deletion via REST API change the error message to reflect the reason for the prevention.
		if ( llms_is_rest() ) {
			// Filter the error message.
			add_filter( 'rest_request_after_callbacks', array( __CLASS__, 'rest_filter_products_with_active_subscriptions_error_message' ), 10, 3 );
		} else { // Deleting via wp-admin.