1 files changed, 108 insertions, 0 deletions
diff --git a/lib/private/Preview/ProviderV2.php b/lib/private/Preview/ProviderV2.php
new file mode 100644
index 00000000000..556d1099d2d
--- /dev/null
+++ b/lib/private/Preview/ProviderV2.php
@@ -0,0 +1,108 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2019 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Preview;
+
+use OCP\Files\File;
+use OCP\Files\FileInfo;
+use OCP\IImage;
+use OCP\ITempManager;
+use OCP\Preview\IProviderV2;
+use OCP\Server;
+use Psr\Log\LoggerInterface;
+
+abstract class ProviderV2 implements IProviderV2 {
+	protected array $tmpFiles = [];
+
+	public function __construct(
+		protected array $options = [],
+	) {
+	}
+
+	/**
+	 * @return string Regex with the mimetypes that are supported by this provider
+	 */
+	abstract public function getMimeType(): string ;
+
+	/**
+	 * Check if a preview can be generated for $path
+	 *
+	 * @param FileInfo $file
+	 * @return bool
+	 */
+	public function isAvailable(FileInfo $file): bool {
+		return true;
+	}
+
+	/**
+	 * get thumbnail for file at path $path
+	 *
+	 * @param File $file
+	 * @param int $maxX The maximum X size of the thumbnail. It can be smaller depending on the shape of the image
+	 * @param int $maxY The maximum Y size of the thumbnail. It can be smaller depending on the shape of the image
+	 * @return null|\OCP\IImage null if no preview was generated
+	 * @since 17.0.0
+	 */
+	abstract public function getThumbnail(File $file, int $maxX, int $maxY): ?IImage;
+
+	protected function useTempFile(File $file): bool {
+		return $file->isEncrypted() || !$file->getStorage()->isLocal();
+	}
+
+	/**
+	 * Get a path to either the local file or temporary file
+	 *
+	 * @param File $file
+	 * @param ?int $maxSize maximum size for temporary files
+	 */
+	protected function getLocalFile(File $file, ?int $maxSize = null): string|false {
+		if ($this->useTempFile($file)) {
+			$absPath = Server::get(ITempManager::class)->getTemporaryFile();
+
+			if ($absPath === false) {
+				Server::get(LoggerInterface::class)->error(
+					'Failed to get local file to generate thumbnail for: ' . $file->getPath(),
+					['app' => 'core']
+				);
+				return false;
+			}
+
+			$content = $file->fopen('r');
+			if ($content === false) {
+				return false;
+			}
+
+			if ($maxSize) {
+				$content = stream_get_contents($content, $maxSize);
+			}
+
+			file_put_contents($absPath, $content);
+			$this->tmpFiles[] = $absPath;
+			return $absPath;
+		} else {
+			$path = $file->getStorage()->getLocalFile($file->getInternalPath());
+			if (is_string($path)) {
+				return $path;
+			} else {
+				return false;
+			}
+		}
+	}
+
+	/**
+	 * Clean any generated temporary files
+	 */
+	protected function cleanTmpFiles(): void {
+		foreach ($this->tmpFiles as $tmpFile) {
+			unlink($tmpFile);
+		}
+
+		$this->tmpFiles = [];
+	}
+}