1 files changed, 109 insertions, 0 deletions
diff --git a/lib/private/Http/WellKnown/RequestManager.php b/lib/private/Http/WellKnown/RequestManager.php
new file mode 100644
index 00000000000..3624bf73962
--- /dev/null
+++ b/lib/private/Http/WellKnown/RequestManager.php
@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2020 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Http\WellKnown;
+
+use OC\AppFramework\Bootstrap\Coordinator;
+use OC\AppFramework\Bootstrap\ServiceRegistration;
+use OCP\AppFramework\QueryException;
+use OCP\Http\WellKnown\IHandler;
+use OCP\Http\WellKnown\IRequestContext;
+use OCP\Http\WellKnown\IResponse;
+use OCP\Http\WellKnown\JrdResponse;
+use OCP\IRequest;
+use OCP\IServerContainer;
+use Psr\Log\LoggerInterface;
+use RuntimeException;
+use function array_reduce;
+
+class RequestManager {
+	/** @var Coordinator */
+	private $coordinator;
+
+	/** @var IServerContainer */
+	private $container;
+
+	/** @var LoggerInterface */
+	private $logger;
+
+	public function __construct(Coordinator $coordinator,
+		IServerContainer $container,
+		LoggerInterface $logger) {
+		$this->coordinator = $coordinator;
+		$this->container = $container;
+		$this->logger = $logger;
+	}
+
+	public function process(string $service, IRequest $request): ?IResponse {
+		$handlers = $this->loadHandlers();
+		$context = new class($request) implements IRequestContext {
+			/** @var IRequest */
+			private $request;
+
+			public function __construct(IRequest $request) {
+				$this->request = $request;
+			}
+
+			public function getHttpRequest(): IRequest {
+				return $this->request;
+			}
+		};
+
+		$subject = $request->getParam('resource');
+		$initialResponse = new JrdResponse($subject ?? '');
+		$finalResponse = array_reduce($handlers, function (?IResponse $previousResponse, IHandler $handler) use ($context, $service) {
+			return $handler->handle($service, $context, $previousResponse);
+		}, $initialResponse);
+
+		if ($finalResponse instanceof JrdResponse && $finalResponse->isEmpty()) {
+			return null;
+		}
+
+		return $finalResponse;
+	}
+
+	/**
+	 * @return IHandler[]
+	 */
+	private function loadHandlers(): array {
+		$context = $this->coordinator->getRegistrationContext();
+
+		if ($context === null) {
+			throw new RuntimeException('Well known handlers requested before the apps had been fully registered');
+		}
+
+		$registrations = $context->getWellKnownHandlers();
+		$this->logger->debug(count($registrations) . ' well known handlers registered');
+
+		return array_filter(
+			array_map(function (ServiceRegistration $registration) {
+				/** @var ServiceRegistration<IHandler> $registration */
+				$class = $registration->getService();
+
+				try {
+					$handler = $this->container->get($class);
+
+					if (!($handler) instanceof IHandler) {
+						$this->logger->error("Well known handler $class is invalid");
+
+						return null;
+					}
+
+					return $handler;
+				} catch (QueryException $e) {
+					$this->logger->error("Could not load well known handler $class", [
+						'exception' => $e,
+						'app' => $registration->getAppId(),
+					]);
+
+					return null;
+				}
+			}, $registrations)
+		);
+	}
+}