class FragmentHandler

class FragmentHandler {
    
    /** @var array<string, FragmentRendererInterface> */
    private array $renderers = [];
    
    /**
     * @param FragmentRendererInterface[] $renderers An array of FragmentRendererInterface instances
     * @param bool                        $debug     Whether the debug mode is enabled or not
     */
    public function __construct(RequestStack $requestStack, array $renderers = [], bool $debug = false) {
        foreach ($renderers as $renderer) {
            $this->addRenderer($renderer);
        }
    }
    
    /**
     * Adds a renderer.
     */
    public function addRenderer(FragmentRendererInterface $renderer) : void {
        $this->renderers[$renderer->getName()] = $renderer;
    }
    
    /**
     * Renders a URI and returns the Response content.
     *
     * Available options:
     *
     *  * ignore_errors: true to return an empty string in case of an error
     *
     * @throws \InvalidArgumentException when the renderer does not exist
     * @throws \LogicException           when no main request is being handled
     */
    public function render(string|ControllerReference $uri, string $renderer = 'inline', array $options = []) : ?string {
        if (!isset($options['ignore_errors'])) {
            $options['ignore_errors'] = !$this->debug;
        }
        if (!isset($this->renderers[$renderer])) {
            throw new \InvalidArgumentException(\sprintf('The "%s" renderer does not exist.', $renderer));
        }
        if (!($request = $this->requestStack
            ->getCurrentRequest())) {
            throw new \LogicException('Rendering a fragment can only be done when handling a Request.');
        }
        return $this->deliver($this->renderers[$renderer]
            ->render($uri, $request, $options));
    }
    
    /**
     * Delivers the Response as a string.
     *
     * When the Response is a StreamedResponse, the content is streamed immediately
     * instead of being returned.
     *
     * @return string|null The Response content or null when the Response is streamed
     *
     * @throws \RuntimeException when the Response is not successful
     */
    protected function deliver(Response $response) : ?string {
        if (!$response->isSuccessful()) {
            $responseStatusCode = $response->getStatusCode();
            throw new \RuntimeException(\sprintf('Error when rendering "%s" (Status code is %d).', $this->requestStack
                ->getCurrentRequest()
                ->getUri(), $responseStatusCode), 0, new HttpException($responseStatusCode));
        }
        if (!$response instanceof StreamedResponse) {
            return $response->getContent();
        }
        $response->sendContent();
        return null;
    }

}