<?php

namespace AOP\App\Rest;

use AOP\App\Fields\FieldRegistry;
use AOP\App\Fields\FieldType;

/**
 * REST API for the field types: `GET aop/v1/field-types`. The editor builds its field picker and the settings
 * form of every field from this list, so an add-on needs no JavaScript for ordinary settings.
 *
 * @since 1.0.0
 * @experimental
 */
class FieldTypesController
{
    public function register(): void
    {
        register_rest_route(PagesController::NAMESPACE, '/field-types', [
            'methods' => \WP_REST_Server::READABLE,
            'callback' => [$this, 'index'],
            'permission_callback' => function () {
                return current_user_can('manage_options');
            },
        ]);
    }

    public function index(): \WP_REST_Response
    {
        $types = [];

        foreach (FieldRegistry::instance()->all() as $type) {
            $types[] = $this->present($type);
        }

        return new \WP_REST_Response([
            'api_level' => FieldRegistry::API_LEVEL,
            'types' => $types,
            'problems' => FieldRegistry::instance()->problems(),
        ]);
    }

    /**
     * What the editor needs to know about a type. The server decides what is stored; the editor only gets the names
     * of named sanitizers, never the rules or callables.
     */
    private function present(FieldType $type): array
    {
        $settings = [];

        foreach ($type->schema() as $setting) {
            // Fixed and derived values are computed on the server; the editor does not ask for them.
            if (!isset($setting['control']) || $setting['control'] === null) {
                continue;
            }

            $entry = array_intersect_key($setting, array_flip(['key', 'control', 'label', 'default', 'options']));

            // Only the name of a named sanitizer ("toggle_onoff") is shared: it tells the editor how a switch posts.
            // Callables stay on the server.
            if (isset($setting['sanitize']) && is_string($setting['sanitize'])) {
                $entry['sanitize'] = $setting['sanitize'];
            }

            $settings[] = $entry;
        }

        return [
            'type' => $type::type(),
            'label' => $type->label(),
            'group' => $type->group(),
            'has_option' => $type->hasOption(),
            'settings' => $settings,
        ];
    }
}