class HttpExceptionNormalizer

class HttpExceptionNormalizer extends NormalizerBase {
    
    /**
     * The interface or class that this Normalizer supports.
     *
     * @var string
     */
    protected $supportedInterfaceOrClass = HttpException::class;
    
    /**
     * The current user making the request.
     *
     * @var \Drupal\Core\Session\AccountInterface
     */
    protected $currentUser;
    
    /**
     * HttpExceptionNormalizer constructor.
     *
     * @param \Drupal\Core\Session\AccountInterface $current_user
     *   The current user.
     */
    public function __construct(AccountInterface $current_user) {
        $this->currentUser = $current_user;
    }
    
    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = NULL, array $context = []) {
        $cacheability = new CacheableMetadata();
        $cacheability->addCacheableDependency($object);
        $cacheability->addCacheTags([
            'config:system.logging',
        ]);
        if (\Drupal::config('system.logging')->get('error_level') === ERROR_REPORTING_DISPLAY_VERBOSE) {
            $cacheability->setCacheMaxAge(0);
        }
        return new HttpExceptionNormalizerValue($cacheability, static::rasterizeValueRecursive($this->buildErrorObjects($object)));
    }
    
    /**
     * Builds the normalized JSON:API error objects for the response.
     *
     * @param \Symfony\Component\HttpKernel\Exception\HttpException $exception
     *   The Exception.
     *
     * @return array
     *   The error objects to include in the response.
     */
    protected function buildErrorObjects(HttpException $exception) {
        $error = [];
        $status_code = $exception->getStatusCode();
        if (!empty(Response::$statusTexts[$status_code])) {
            $error['title'] = Response::$statusTexts[$status_code];
        }
        $error += [
            'status' => (string) $status_code,
            'detail' => $exception->getMessage(),
        ];
        $error['links']['via']['href'] = \Drupal::request()->getUri();
        // Provide an "info" link by default: if the exception carries a single
        // "Link" header, use that, otherwise fall back to the HTTP spec section
        // covering the exception's status code.
        $headers = $exception->getHeaders();
        if (isset($headers['Link']) && !is_array($headers['Link'])) {
            $error['links']['info']['href'] = $headers['Link'];
        }
        elseif ($info_url = $this->getInfoUrl($status_code)) {
            $error['links']['info']['href'] = $info_url;
        }
        // Exceptions thrown without an explicitly defined code get assigned zero by
        // default. Since this is no helpful information, omit it.
        if ($exception->getCode() !== 0) {
            $error['code'] = (string) $exception->getCode();
        }
        $is_verbose_reporting = \Drupal::config('system.logging')->get('error_level') === ERROR_REPORTING_DISPLAY_VERBOSE;
        $site_report_access = $this->currentUser
            ->hasPermission('access site reports');
        if ($site_report_access && $is_verbose_reporting) {
            // The following information may contain sensitive information. Only show
            // it to authorized users.
            $error['source'] = [
                'file' => $exception->getFile(),
                'line' => $exception->getLine(),
            ];
            $error['meta'] = [
                'exception' => (string) $exception,
                'trace' => $exception->getTrace(),
            ];
        }
        return [
            $error,
        ];
    }
    
    /**
     * Return a string to the common problem type.
     *
     * @return string|null
     *   URL pointing to the specific RFC-2616 section. Or NULL if it is an HTTP
     *   status code that is defined in another RFC.
     *
     * @see https://www.drupal.org/project/drupal/issues/2832211#comment-11826234
     *
     * @internal
     */
    public static function getInfoUrl($status_code) {
        // Depending on the error code we'll return a different URL.
        $url = 'http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html';
        $sections = [
            '100' => '#sec10.1.1',
            '101' => '#sec10.1.2',
            '200' => '#sec10.2.1',
            '201' => '#sec10.2.2',
            '202' => '#sec10.2.3',
            '203' => '#sec10.2.4',
            '204' => '#sec10.2.5',
            '205' => '#sec10.2.6',
            '206' => '#sec10.2.7',
            '300' => '#sec10.3.1',
            '301' => '#sec10.3.2',
            '302' => '#sec10.3.3',
            '303' => '#sec10.3.4',
            '304' => '#sec10.3.5',
            '305' => '#sec10.3.6',
            '307' => '#sec10.3.8',
            '400' => '#sec10.4.1',
            '401' => '#sec10.4.2',
            '402' => '#sec10.4.3',
            '403' => '#sec10.4.4',
            '404' => '#sec10.4.5',
            '405' => '#sec10.4.6',
            '406' => '#sec10.4.7',
            '407' => '#sec10.4.8',
            '408' => '#sec10.4.9',
            '409' => '#sec10.4.10',
            '410' => '#sec10.4.11',
            '411' => '#sec10.4.12',
            '412' => '#sec10.4.13',
            '413' => '#sec10.4.14',
            '414' => '#sec10.4.15',
            '415' => '#sec10.4.16',
            '416' => '#sec10.4.17',
            '417' => '#sec10.4.18',
            '500' => '#sec10.5.1',
            '501' => '#sec10.5.2',
            '502' => '#sec10.5.3',
            '503' => '#sec10.5.4',
            '504' => '#sec10.5.5',
            '505' => '#sec10.5.6',
        ];
        return empty($sections[$status_code]) ? NULL : $url . $sections[$status_code];
    }
    
    /**
     * {@inheritdoc}
     */
    public function hasCacheableSupportsMethod() : bool {
        return TRUE;
    }

}