ResourceController.php

<?php

namespace Drupal\media_test_oembed\Controller;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * Test controller returning oEmbed resources from Media's test fixtures.
 */
class ResourceController {
    
    /**
     * Creates an oEmbed resource response.
     *
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The request.
     *
     * @return \Symfony\Component\HttpFoundation\Response
     *   The oEmbed resource response.
     */
    public function get(Request $request) {
        $asset_url = $request->query
            ->get('url');
        $resources = \Drupal::state()->get(static::class, []);
        if ($resources[$asset_url] === 404) {
            $response = new Response('Not Found', 404);
        }
        else {
            $content = file_get_contents($resources[$asset_url]);
            $response = new Response($content);
            $response->headers
                ->set('Content-Type', 'application/json');
        }
        return $response;
    }
    
    /**
     * Maps an asset URL to a local fixture representing its oEmbed resource.
     *
     * @param string $asset_url
     *   The asset URL.
     * @param string $resource_path
     *   The path of the oEmbed resource representing the asset.
     */
    public static function setResourceUrl($asset_url, $resource_path) {
        $resources = \Drupal::state()->get(static::class, []);
        $resources[$asset_url] = $resource_path;
        \Drupal::state()->set(static::class, $resources);
    }
    
    /**
     * Maps an asset URL to a 404 response.
     *
     * @param string $asset_url
     *   The asset URL.
     */
    public static function setResource404($asset_url) {
        $resources = \Drupal::state()->get(static::class, []);
        $resources[$asset_url] = 404;
        \Drupal::state()->set(static::class, $resources);
    }

}