TYPO3 YoutUbe Placeholder Image Viewhelper

<?php

namespace ZC\Zebracode\ViewHelpers\Youtube;

use TYPO3Fluid\Fluid\Core\ViewHelper\AbstractViewHelper;


/**
 * Class YoutubePlaceholderViewHelper
 * @package ZC\Zebracode\ViewHelpers
 */
class PlaceholderUrlViewHelper extends AbstractViewHelper
{
    /**
     * @throws \TYPO3\CMS\Fluid\Core\ViewHelper\Exception
     */
    public function initializeArguments()
    {
        $this->registerArgument(
            'ytid',
            'string',
            'The ID of a YouTube video to fetch a thumbnail image for.',
            true
        );
    }

    /**
     * @param string $ytid
     * @return string
     */
    public function render($ytid)
    {

        return $this->fetchYoutubeThumbnailUrl($ytid);

    }

    /**
     * Helper function for retrieving Youtube posters
     *
     * @param $id
     * @return string
     */
    protected function fetchYoutubeThumbnailUrl($id)
    {
        // different resolutions starting with the highest
        $resolution = [
            'maxresdefault',
            'sddefault',
            'mqdefault',
            'hqdefault',
            'default'
        ];

        // Fallback image, should be replaced in the future
        $url = 'https://www.placehold.it/420x255?text=YoutubeVideo';

        for ($x = 0; $x < sizeof($resolution); $x++) {
            $url = 'https://img.youtube.com/vi/' . $id . '/' . $resolution[$x] . '.jpg';
            if (get_headers($url)[0] == 'HTTP/1.0 200 OK') {
                break;
            }
        }
        return $url;
    }
}