<?php
/** Declared public REST metadata; values are independently fetched anonymously by SaaS. */
if (!defined('ABSPATH')) { exit; }

final class Chat4U_Public_Fields {
    private static array $cache = [];

    public static function fields(string $type): array {
        if (isset(self::$cache[$type])) { return self::$cache[$type]; }
        $object = get_post_type_object($type);
        if (!$object || !$object->show_in_rest) { return self::$cache[$type] = []; }
        rest_get_server();
        $controller = $object->get_rest_controller();
        if (!$controller) { return self::$cache[$type] = []; }
        $properties = $controller->get_item_schema()['properties']['meta']['properties'] ?? [];
        $registered = array_merge(get_registered_meta_keys('post'), get_registered_meta_keys('post', $type));
        $result = [];
        ksort($registered);
        foreach ($registered as $key => $value) {
            if (empty($value['show_in_rest'])) { continue; }
            $name = is_array($value['show_in_rest']) ? ($value['show_in_rest']['name'] ?? $key) : $key;
            if (preg_match('/(?:^|[_-])(password|secret|api[_-]?key|access[_-]?token|refresh[_-]?token|nonce|author[_-]?email|user[_-]?email)(?:$|[_-])/i', $name)) { continue; }
            if (!isset($properties[$name]) || !in_array('view', $properties[$name]['context'] ?? ['view', 'edit'], true)) { continue; }
            $result[$name] = ['key' => $key, 'schema' => $properties[$name]];
        }
        return self::$cache[$type] = $result;
    }

    public static function schema(string $type): array {
        $properties = [];
        foreach (self::fields($type) as $name => $value) { $properties[$name] = $value['schema']; }
        return ['type' => 'object', 'properties' => (object) $properties];
    }

    public static function schemas(): array {
        $result = [];
        foreach (Chat4U_Content::types() as $type) { $result[$type] = self::schema($type); }
        return $result;
    }

    public static function record(int $id, string $type): array {
        $fields = self::fields($type);
        if (!$fields) { return []; }
        $object = get_post_type_object($type);
        $namespace = $object->rest_namespace ?: 'wp/v2';
        $base = $object->rest_base ?: $type;
        $url = add_query_arg(['context' => 'view', '_fields' => 'id,meta'], get_rest_url(null, $namespace . '/' . $base . '/' . $id));
        $present = [];
        foreach ($fields as $name => $value) {
            if (metadata_exists('post', $id, $value['key'])) { $present[] = $name; }
        }
        return ['public_meta_url' => $url, 'public_meta_schema' => self::schema($type), 'public_meta_present' => $present];
    }
}