<?php
/**
 * Product Attributes REST API Controller.
 *
 * Provides CRUD endpoints for WooCommerce product attributes and terms.
 * Required for variable product synchronization.
 *
 * @package GeniusCommerce
 */

namespace GeniusCommerce\REST_API;

use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;
use WP_Error;

defined( 'ABSPATH' ) || exit;

/**
 * GC_REST_Attributes class.
 *
 * Handles product attributes and attribute terms:
 * - GET /attributes - List all product attributes
 * - POST /attributes - Create attribute
 * - GET /attributes/{id} - Get single attribute
 * - PUT /attributes/{id} - Update attribute
 * - DELETE /attributes/{id} - Delete attribute
 * - GET /attributes/{id}/terms - List attribute terms
 * - POST /attributes/{id}/terms - Create attribute term
 * - PUT /attributes/{id}/terms/{term_id} - Update attribute term
 * - DELETE /attributes/{id}/terms/{term_id} - Delete attribute term
 * - POST /attributes/{id}/terms/batch - Batch operations on terms
 */
class GC_REST_Attributes extends GC_REST_Controller {

    /**
     * REST base for this controller.
     *
     * @var string
     */
    protected $rest_base = 'attributes';

    /**
     * Register REST API routes.
     *
     * @return void
     */
    public function register_routes(): void {
        // GET /attributes - List attributes.
        // POST /attributes - Create attribute.
        register_rest_route(
            $this->namespace,
            '/' . $this->rest_base,
            array(
                array(
                    'methods'             => WP_REST_Server::READABLE,
                    'callback'            => array( $this, 'get_items' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
                array(
                    'methods'             => WP_REST_Server::CREATABLE,
                    'callback'            => array( $this, 'create_item' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
            )
        );

        // GET /attributes/{id} - Get single attribute.
        // PUT /attributes/{id} - Update attribute.
        // DELETE /attributes/{id} - Delete attribute.
        register_rest_route(
            $this->namespace,
            '/' . $this->rest_base . '/(?P<id>[\d]+)',
            array(
                array(
                    'methods'             => WP_REST_Server::READABLE,
                    'callback'            => array( $this, 'get_item' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
                array(
                    'methods'             => WP_REST_Server::EDITABLE,
                    'callback'            => array( $this, 'update_item' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
                array(
                    'methods'             => WP_REST_Server::DELETABLE,
                    'callback'            => array( $this, 'delete_item' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
            )
        );

        // GET /attributes/{id}/terms - List attribute terms.
        // POST /attributes/{id}/terms - Create attribute term.
        register_rest_route(
            $this->namespace,
            '/' . $this->rest_base . '/(?P<attribute_id>[\d]+)/terms',
            array(
                array(
                    'methods'             => WP_REST_Server::READABLE,
                    'callback'            => array( $this, 'get_terms' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
                array(
                    'methods'             => WP_REST_Server::CREATABLE,
                    'callback'            => array( $this, 'create_term' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
            )
        );

        // PUT /attributes/{id}/terms/{term_id} - Update attribute term.
        // DELETE /attributes/{id}/terms/{term_id} - Delete attribute term.
        register_rest_route(
            $this->namespace,
            '/' . $this->rest_base . '/(?P<attribute_id>[\d]+)/terms/(?P<term_id>[\d]+)',
            array(
                array(
                    'methods'             => WP_REST_Server::EDITABLE,
                    'callback'            => array( $this, 'update_term' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
                array(
                    'methods'             => WP_REST_Server::DELETABLE,
                    'callback'            => array( $this, 'delete_term' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
            )
        );

        // POST /attributes/{id}/terms/batch - Batch operations on terms.
        register_rest_route(
            $this->namespace,
            '/' . $this->rest_base . '/(?P<attribute_id>[\d]+)/terms/batch',
            array(
                array(
                    'methods'             => WP_REST_Server::CREATABLE,
                    'callback'            => array( $this, 'batch_terms' ),
                    'permission_callback' => function ( \WP_REST_Request $r ) { return $this->check_scope( $r, \GeniusCommerce\GC_Scope_Map::for_request( $r ) ); },
                ),
            )
        );
    }

    /**
     * Get all product attributes.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function get_items( $request ) {
        $this->log_request( 'GET /attributes', $request->get_params() );

        $raw_attributes = wc_get_attribute_taxonomies();
        $data           = array();

        foreach ( $raw_attributes as $raw_attribute ) {
            // wc_get_attribute_taxonomies returns objects with attribute_* properties
            // We need to get the full attribute object using wc_get_attribute()
            $attribute = wc_get_attribute( $raw_attribute->attribute_id );
            if ( $attribute ) {
                $data[] = $this->prepare_attribute_for_response( $attribute );
            }
        }

        return new WP_REST_Response(
            array( 'data' => $data ),
            200
        );
    }

    /**
     * Get a single attribute.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function get_item( $request ) {
        $id = (int) $request->get_param( 'id' );
        $this->log_request( 'GET /attributes/' . $id, array() );

        $attribute = wc_get_attribute( $id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        return new WP_REST_Response(
            array( 'data' => $this->prepare_attribute_for_response( $attribute ) ),
            200
        );
    }

    /**
     * Create a new attribute.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function create_item( $request ) {
        $this->log_request( 'POST /attributes', array() );

        $data = $request->get_json_params();

        if ( empty( $data['name'] ) ) {
            return new WP_Error(
                'gc_missing_name',
                __( 'Attribuut naam is verplicht.', 'genius-commerce' ),
                array( 'status' => 400 )
            );
        }

        // Check if attribute already exists by slug.
        $slug = isset( $data['slug'] ) ? sanitize_title( $data['slug'] ) : sanitize_title( $data['name'] );
        $existing = $this->get_attribute_by_slug( $slug );

        if ( $existing ) {
            // Return existing attribute instead of error.
            return new WP_REST_Response(
                array(
                    'data'    => $this->prepare_attribute_for_response( $existing ),
                    'message' => __( 'Attribuut bestaat al.', 'genius-commerce' ),
                    'created' => false,
                ),
                200
            );
        }

        // Create the attribute.
        $attribute_id = wc_create_attribute(
            array(
                'name'         => sanitize_text_field( $data['name'] ),
                'slug'         => $slug,
                'type'         => isset( $data['type'] ) ? sanitize_text_field( $data['type'] ) : 'select',
                'order_by'     => isset( $data['order_by'] ) ? sanitize_text_field( $data['order_by'] ) : 'menu_order',
                'has_archives' => isset( $data['has_archives'] ) ? (bool) $data['has_archives'] : false,
            )
        );

        if ( is_wp_error( $attribute_id ) ) {
            return $attribute_id;
        }

        // Immediately register the taxonomy so it's available in the same request.
        // WooCommerce normally registers taxonomies on init, but we need it now.
        $this->register_attribute_taxonomy( $slug );

        $attribute = wc_get_attribute( $attribute_id );

        return new WP_REST_Response(
            array(
                'data'    => $this->prepare_attribute_for_response( $attribute ),
                'message' => __( 'Attribuut aangemaakt.', 'genius-commerce' ),
                'created' => true,
            ),
            201
        );
    }

    /**
     * Register an attribute taxonomy immediately.
     *
     * WooCommerce typically registers attribute taxonomies on the 'init' hook,
     * but when creating attributes via API and immediately using them,
     * we need to register them in the same request.
     *
     * @param string $attribute_slug The attribute slug (without pa_ prefix).
     * @return void
     */
    protected function register_attribute_taxonomy( string $attribute_slug ): void {
        $taxonomy_name = wc_attribute_taxonomy_name( $attribute_slug );

        // Skip if already registered.
        if ( taxonomy_exists( $taxonomy_name ) ) {
            return;
        }

        // Get attribute data from database.
        global $wpdb;
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Prepared read with no core API equivalent; sync correctness requires uncached data.
        $attribute = $wpdb->get_row(
            $wpdb->prepare(
                "SELECT * FROM {$wpdb->prefix}woocommerce_attribute_taxonomies WHERE attribute_name = %s",
                $attribute_slug
            )
        );

        if ( ! $attribute ) {
            return;
        }

        // Register the taxonomy with WooCommerce standard settings.
        // These are WooCommerce's own attribute-taxonomy filters, re-applied here
        // so third-party code keeps working exactly as it does for core-registered
        // attributes. They are not ours to prefix.
        // phpcs:disable WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
        register_taxonomy(
            $taxonomy_name,
            apply_filters( 'woocommerce_taxonomy_objects_' . $taxonomy_name, array( 'product' ) ),
            apply_filters(
                'woocommerce_taxonomy_args_' . $taxonomy_name,
                array(
                    'hierarchical' => false,
                    'show_ui'      => false,
                    'query_var'    => true,
                    'rewrite'      => false,
                    'sort'         => false,
                )
            )
        );
        // phpcs:enable WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
    }

    /**
     * Update an attribute.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function update_item( $request ) {
        $id = (int) $request->get_param( 'id' );
        $this->log_request( 'PUT /attributes/' . $id, array() );

        $attribute = wc_get_attribute( $id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $data = $request->get_json_params();

        $update_args = array( 'id' => $id );

        if ( isset( $data['name'] ) ) {
            $update_args['name'] = sanitize_text_field( $data['name'] );
        }
        if ( isset( $data['slug'] ) ) {
            $update_args['slug'] = sanitize_title( $data['slug'] );
        }
        if ( isset( $data['type'] ) ) {
            $update_args['type'] = sanitize_text_field( $data['type'] );
        }
        if ( isset( $data['order_by'] ) ) {
            $update_args['order_by'] = sanitize_text_field( $data['order_by'] );
        }
        if ( isset( $data['has_archives'] ) ) {
            $update_args['has_archives'] = (bool) $data['has_archives'];
        }

        $result = wc_update_attribute( $id, $update_args );

        if ( is_wp_error( $result ) ) {
            return $result;
        }

        $attribute = wc_get_attribute( $id );

        return new WP_REST_Response(
            array(
                'data'    => $this->prepare_attribute_for_response( $attribute ),
                'message' => __( 'Attribuut bijgewerkt.', 'genius-commerce' ),
            ),
            200
        );
    }

    /**
     * Delete an attribute.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function delete_item( $request ) {
        $id = (int) $request->get_param( 'id' );
        $this->log_request( 'DELETE /attributes/' . $id, array() );

        $attribute = wc_get_attribute( $id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $response_data = $this->prepare_attribute_for_response( $attribute );

        $result = wc_delete_attribute( $id );

        if ( ! $result ) {
            return new WP_Error(
                'gc_attribute_delete_failed',
                __( 'Attribuut verwijderen mislukt.', 'genius-commerce' ),
                array( 'status' => 500 )
            );
        }

        return new WP_REST_Response(
            array(
                'data'    => $response_data,
                'message' => __( 'Attribuut verwijderd.', 'genius-commerce' ),
                'deleted' => true,
            ),
            200
        );
    }

    /**
     * Get terms for an attribute.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function get_terms( $request ) {
        $attribute_id = (int) $request->get_param( 'attribute_id' );
        $this->log_request( 'GET /attributes/' . $attribute_id . '/terms', array() );

        $attribute = wc_get_attribute( $attribute_id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $taxonomy = wc_attribute_taxonomy_name_by_id( $attribute_id );
        $terms    = get_terms(
            array(
                'taxonomy'   => $taxonomy,
                'hide_empty' => false,
                'orderby'    => 'menu_order',
                'order'      => 'ASC',
            )
        );

        if ( is_wp_error( $terms ) ) {
            return $terms;
        }

        $data = array();
        foreach ( $terms as $term ) {
            $data[] = $this->prepare_term_for_response( $term );
        }

        return new WP_REST_Response(
            array( 'data' => $data ),
            200
        );
    }

    /**
     * Create a term for an attribute.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function create_term( $request ) {
        $attribute_id = (int) $request->get_param( 'attribute_id' );
        $this->log_request( 'POST /attributes/' . $attribute_id . '/terms', array() );

        $attribute = wc_get_attribute( $attribute_id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $data = $request->get_json_params();

        if ( empty( $data['name'] ) ) {
            return new WP_Error(
                'gc_missing_name',
                __( 'Term naam is verplicht.', 'genius-commerce' ),
                array( 'status' => 400 )
            );
        }

        $taxonomy = wc_attribute_taxonomy_name_by_id( $attribute_id );

        // Check if term already exists.
        $existing = get_term_by( 'name', $data['name'], $taxonomy );
        if ( $existing ) {
            return new WP_REST_Response(
                array(
                    'data'    => $this->prepare_term_for_response( $existing ),
                    'message' => __( 'Term bestaat al.', 'genius-commerce' ),
                    'created' => false,
                ),
                200
            );
        }

        $term_args = array(
            'slug' => isset( $data['slug'] ) ? sanitize_title( $data['slug'] ) : '',
        );

        if ( isset( $data['description'] ) ) {
            $term_args['description'] = sanitize_textarea_field( $data['description'] );
        }

        $result = wp_insert_term( sanitize_text_field( $data['name'] ), $taxonomy, $term_args );

        if ( is_wp_error( $result ) ) {
            return $result;
        }

        // Set menu_order if provided.
        if ( isset( $data['menu_order'] ) ) {
            update_term_meta( $result['term_id'], 'order', (int) $data['menu_order'] );
        }

        $term = get_term( $result['term_id'], $taxonomy );

        return new WP_REST_Response(
            array(
                'data'    => $this->prepare_term_for_response( $term ),
                'message' => __( 'Term aangemaakt.', 'genius-commerce' ),
                'created' => true,
            ),
            201
        );
    }

    /**
     * Update a term.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function update_term( $request ) {
        $attribute_id = (int) $request->get_param( 'attribute_id' );
        $term_id      = (int) $request->get_param( 'term_id' );
        $this->log_request( 'PUT /attributes/' . $attribute_id . '/terms/' . $term_id, array() );

        $attribute = wc_get_attribute( $attribute_id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $taxonomy = wc_attribute_taxonomy_name_by_id( $attribute_id );
        $term     = get_term( $term_id, $taxonomy );

        if ( ! $term || is_wp_error( $term ) ) {
            return new WP_Error(
                'gc_term_not_found',
                __( 'Term niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $data = $request->get_json_params();

        $update_args = array();
        if ( isset( $data['name'] ) ) {
            $update_args['name'] = sanitize_text_field( $data['name'] );
        }
        if ( isset( $data['slug'] ) ) {
            $update_args['slug'] = sanitize_title( $data['slug'] );
        }
        if ( isset( $data['description'] ) ) {
            $update_args['description'] = sanitize_textarea_field( $data['description'] );
        }

        if ( ! empty( $update_args ) ) {
            $result = wp_update_term( $term_id, $taxonomy, $update_args );

            if ( is_wp_error( $result ) ) {
                return $result;
            }
        }

        // Update menu_order if provided.
        if ( isset( $data['menu_order'] ) ) {
            update_term_meta( $term_id, 'order', (int) $data['menu_order'] );
        }

        $term = get_term( $term_id, $taxonomy );

        return new WP_REST_Response(
            array(
                'data'    => $this->prepare_term_for_response( $term ),
                'message' => __( 'Term bijgewerkt.', 'genius-commerce' ),
            ),
            200
        );
    }

    /**
     * Delete a term.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function delete_term( $request ) {
        $attribute_id = (int) $request->get_param( 'attribute_id' );
        $term_id      = (int) $request->get_param( 'term_id' );
        $this->log_request( 'DELETE /attributes/' . $attribute_id . '/terms/' . $term_id, array() );

        $attribute = wc_get_attribute( $attribute_id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $taxonomy = wc_attribute_taxonomy_name_by_id( $attribute_id );
        $term     = get_term( $term_id, $taxonomy );

        if ( ! $term || is_wp_error( $term ) ) {
            return new WP_Error(
                'gc_term_not_found',
                __( 'Term niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $response_data = $this->prepare_term_for_response( $term );

        $result = wp_delete_term( $term_id, $taxonomy );

        if ( is_wp_error( $result ) ) {
            return $result;
        }

        if ( ! $result ) {
            return new WP_Error(
                'gc_term_delete_failed',
                __( 'Term verwijderen mislukt.', 'genius-commerce' ),
                array( 'status' => 500 )
            );
        }

        return new WP_REST_Response(
            array(
                'data'    => $response_data,
                'message' => __( 'Term verwijderd.', 'genius-commerce' ),
                'deleted' => true,
            ),
            200
        );
    }

    /**
     * Batch operations on terms.
     *
     * @param WP_REST_Request $request The request object.
     * @return WP_REST_Response|WP_Error Response object or error.
     */
    public function batch_terms( $request ) {
        $attribute_id = (int) $request->get_param( 'attribute_id' );
        $this->log_request( 'POST /attributes/' . $attribute_id . '/terms/batch', array() );

        $attribute = wc_get_attribute( $attribute_id );

        if ( ! $attribute ) {
            return new WP_Error(
                'gc_attribute_not_found',
                __( 'Attribuut niet gevonden.', 'genius-commerce' ),
                array( 'status' => 404 )
            );
        }

        $data = $request->get_json_params();

        $create = isset( $data['create'] ) ? (array) $data['create'] : array();
        $update = isset( $data['update'] ) ? (array) $data['update'] : array();
        $delete = isset( $data['delete'] ) ? (array) $data['delete'] : array();

        // Enforce batch limit.
        $total = count( $create ) + count( $update ) + count( $delete );
        if ( $total > 100 ) {
            return new WP_Error(
                'gc_batch_limit_exceeded',
                __( 'Maximum 100 operaties per batch request.', 'genius-commerce' ),
                array( 'status' => 400 )
            );
        }

        $taxonomy = wc_attribute_taxonomy_name_by_id( $attribute_id );
        $results  = array(
            'create' => array(),
            'update' => array(),
            'delete' => array(),
        );

        // Process creates.
        foreach ( $create as $item ) {
            if ( empty( $item['name'] ) ) {
                $results['create'][] = array(
                    'error'   => true,
                    'message' => __( 'Term naam is verplicht.', 'genius-commerce' ),
                );
                continue;
            }

            // Check if term already exists.
            $existing = get_term_by( 'name', $item['name'], $taxonomy );
            if ( $existing ) {
                $results['create'][] = $this->prepare_term_for_response( $existing );
                continue;
            }

            $term_args = array();
            if ( isset( $item['slug'] ) ) {
                $term_args['slug'] = sanitize_title( $item['slug'] );
            }

            $result = wp_insert_term( sanitize_text_field( $item['name'] ), $taxonomy, $term_args );

            if ( is_wp_error( $result ) ) {
                $results['create'][] = array(
                    'error'   => true,
                    'message' => $result->get_error_message(),
                );
            } else {
                if ( isset( $item['menu_order'] ) ) {
                    update_term_meta( $result['term_id'], 'order', (int) $item['menu_order'] );
                }
                $term                = get_term( $result['term_id'], $taxonomy );
                $results['create'][] = $this->prepare_term_for_response( $term );
            }
        }

        // Process updates.
        foreach ( $update as $item ) {
            if ( empty( $item['id'] ) ) {
                $results['update'][] = array(
                    'error'   => true,
                    'message' => __( 'Term ID is verplicht voor update.', 'genius-commerce' ),
                );
                continue;
            }

            $term = get_term( $item['id'], $taxonomy );
            if ( ! $term || is_wp_error( $term ) ) {
                $results['update'][] = array(
                    'id'      => $item['id'],
                    'error'   => true,
                    'message' => __( 'Term niet gevonden.', 'genius-commerce' ),
                );
                continue;
            }

            $update_args = array();
            if ( isset( $item['name'] ) ) {
                $update_args['name'] = sanitize_text_field( $item['name'] );
            }
            if ( isset( $item['slug'] ) ) {
                $update_args['slug'] = sanitize_title( $item['slug'] );
            }

            if ( ! empty( $update_args ) ) {
                $result = wp_update_term( $item['id'], $taxonomy, $update_args );
                if ( is_wp_error( $result ) ) {
                    $results['update'][] = array(
                        'id'      => $item['id'],
                        'error'   => true,
                        'message' => $result->get_error_message(),
                    );
                    continue;
                }
            }

            if ( isset( $item['menu_order'] ) ) {
                update_term_meta( $item['id'], 'order', (int) $item['menu_order'] );
            }

            $term                = get_term( $item['id'], $taxonomy );
            $results['update'][] = $this->prepare_term_for_response( $term );
        }

        // Process deletes.
        foreach ( $delete as $term_id ) {
            $term = get_term( $term_id, $taxonomy );
            if ( ! $term || is_wp_error( $term ) ) {
                $results['delete'][] = array(
                    'id'      => $term_id,
                    'error'   => true,
                    'message' => __( 'Term niet gevonden.', 'genius-commerce' ),
                );
                continue;
            }

            $result = wp_delete_term( $term_id, $taxonomy );

            if ( is_wp_error( $result ) || ! $result ) {
                $results['delete'][] = array(
                    'id'      => $term_id,
                    'error'   => true,
                    'message' => __( 'Term verwijderen mislukt.', 'genius-commerce' ),
                );
            } else {
                $results['delete'][] = array(
                    'id'      => $term_id,
                    'deleted' => true,
                );
            }
        }

        return new WP_REST_Response( array( 'data' => $results ), 200 );
    }

    /**
     * Prepare an attribute for the REST response.
     *
     * @param object $attribute The attribute object.
     * @return array Prepared attribute data.
     */
    protected function prepare_attribute_for_response( $attribute ): array {
        $taxonomy = wc_attribute_taxonomy_name_by_id( $attribute->id );
        $terms    = get_terms(
            array(
                'taxonomy'   => $taxonomy,
                'hide_empty' => false,
            )
        );

        $term_data = array();
        if ( ! is_wp_error( $terms ) && ! empty( $terms ) ) {
            foreach ( $terms as $term ) {
                $term_data[] = array(
                    'term_id' => (int) $term->term_id,
                    'name'    => $term->name,
                    'slug'    => $term->slug,
                );
            }
        }

        return array(
            'id'           => (int) $attribute->id,
            'name'         => $attribute->name,
            'slug'         => $attribute->slug,
            'type'         => $attribute->type,
            'order_by'     => $attribute->order_by,
            'has_archives' => (bool) $attribute->has_archives,
            'terms'        => $term_data,
        );
    }

    /**
     * Prepare a term for the REST response.
     *
     * @param \WP_Term $term The term object.
     * @return array Prepared term data.
     */
    protected function prepare_term_for_response( $term ): array {
        return array(
            'id'          => (int) $term->term_id,
            'name'        => $term->name,
            'slug'        => $term->slug,
            'description' => $term->description,
            'menu_order'  => (int) get_term_meta( $term->term_id, 'order', true ),
            'count'       => (int) $term->count,
        );
    }

    /**
     * Get an attribute by its slug.
     *
     * @param string $slug The attribute slug.
     * @return object|null The attribute object or null.
     */
    protected function get_attribute_by_slug( string $slug ) {
        $attributes = wc_get_attribute_taxonomies();

        foreach ( $attributes as $attribute ) {
            if ( $attribute->attribute_name === $slug ) {
                return wc_get_attribute( $attribute->attribute_id );
            }
        }

        return null;
    }
}