1 files changed, 69 insertions, 0 deletions
diff --git a/core/Controller/ReferenceController.php b/core/Controller/ReferenceController.php
new file mode 100644
index 00000000000..6ed15e2d2f1
--- /dev/null
+++ b/core/Controller/ReferenceController.php
@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2022 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Core\Controller;
+
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\Attribute\FrontpageRoute;
+use OCP\AppFramework\Http\Attribute\NoCSRFRequired;
+use OCP\AppFramework\Http\Attribute\OpenAPI;
+use OCP\AppFramework\Http\Attribute\PublicPage;
+use OCP\AppFramework\Http\DataDownloadResponse;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\Collaboration\Reference\IReferenceManager;
+use OCP\Files\AppData\IAppDataFactory;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
+use OCP\IRequest;
+
+class ReferenceController extends Controller {
+	public function __construct(
+		string $appName,
+		IRequest $request,
+		private IReferenceManager $referenceManager,
+		private IAppDataFactory $appDataFactory,
+	) {
+		parent::__construct($appName, $request);
+	}
+
+	/**
+	 * Get a preview for a reference
+	 *
+	 * @param string $referenceId the reference cache key
+	 * @return DataDownloadResponse<Http::STATUS_OK, string, array{}>|DataResponse<Http::STATUS_NOT_FOUND, '', array{}>
+	 *
+	 * 200: Preview returned
+	 * 404: Reference not found
+	 */
+	#[PublicPage]
+	#[NoCSRFRequired]
+	#[FrontpageRoute(verb: 'GET', url: '/core/references/preview/{referenceId}')]
+	#[OpenAPI(scope: OpenAPI::SCOPE_DEFAULT)]
+	public function preview(string $referenceId): DataDownloadResponse|DataResponse {
+		$reference = $this->referenceManager->getReferenceByCacheKey($referenceId);
+
+		try {
+			$appData = $this->appDataFactory->get('core');
+			$folder = $appData->getFolder('opengraph');
+			$file = $folder->getFile($referenceId);
+			$contentType = $reference === null || $reference->getImageContentType() === null
+				? $file->getMimeType()
+				: $reference->getImageContentType();
+			$response = new DataDownloadResponse(
+				$file->getContent(),
+				$referenceId,
+				$contentType
+			);
+		} catch (NotFoundException|NotPermittedException $e) {
+			$response = new DataResponse('', Http::STATUS_NOT_FOUND);
+		}
+		$response->cacheFor(3600, false, true);
+		return $response;
+	}
+}