class ProviderRepository

class ProviderRepository implements ProviderRepositoryInterface {
    use UseCacheBackendTrait;
    
    /**
     * How long the provider data should be cached, in seconds.
     *
     * @var int
     */
    protected $maxAge;
    
    /**
     * The HTTP client.
     *
     * @var \GuzzleHttp\Client
     */
    protected $httpClient;
    
    /**
     * URL of a JSON document which contains a database of oEmbed providers.
     *
     * @var string
     */
    protected $providersUrl;
    
    /**
     * The time service.
     *
     * @var \Drupal\Component\Datetime\TimeInterface
     */
    protected $time;
    
    /**
     * Constructs a ProviderRepository instance.
     *
     * @param \GuzzleHttp\ClientInterface $http_client
     *   The HTTP client.
     * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
     *   The config factory service.
     * @param \Drupal\Component\Datetime\TimeInterface $time
     *   The time service.
     * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
     *   (optional) The cache backend.
     * @param int $max_age
     *   (optional) How long the cache data should be kept. Defaults to a week.
     */
    public function __construct(ClientInterface $http_client, ConfigFactoryInterface $config_factory, TimeInterface $time, CacheBackendInterface $cache_backend = NULL, $max_age = 604800) {
        $this->httpClient = $http_client;
        $this->providersUrl = $config_factory->get('media.settings')
            ->get('oembed_providers_url');
        $this->time = $time;
        $this->cacheBackend = $cache_backend;
        $this->maxAge = (int) $max_age;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getAll() {
        $cache_id = 'media:oembed_providers';
        $cached = $this->cacheGet($cache_id);
        if ($cached) {
            return $cached->data;
        }
        try {
            $response = $this->httpClient
                ->request('GET', $this->providersUrl);
        } catch (RequestException $e) {
            throw new ProviderException("Could not retrieve the oEmbed provider database from {$this->providersUrl}", NULL, $e);
        }
        $providers = Json::decode((string) $response->getBody());
        if (!is_array($providers) || empty($providers)) {
            throw new ProviderException('Remote oEmbed providers database returned invalid or empty list.');
        }
        $keyed_providers = [];
        foreach ($providers as $provider) {
            try {
                $name = (string) $provider['provider_name'];
                $keyed_providers[$name] = new Provider($provider['provider_name'], $provider['provider_url'], $provider['endpoints']);
            } catch (ProviderException $e) {
                // Just skip all the invalid providers.
                // @todo Log the exception message to help with debugging.
            }
        }
        $this->cacheSet($cache_id, $keyed_providers, $this->time
            ->getCurrentTime() + $this->maxAge);
        return $keyed_providers;
    }
    
    /**
     * {@inheritdoc}
     */
    public function get($provider_name) {
        $providers = $this->getAll();
        if (!isset($providers[$provider_name])) {
            throw new \InvalidArgumentException("Unknown provider '{$provider_name}'");
        }
        return $providers[$provider_name];
    }

}