feat: added backend metadata interface, allows JSON storage

Signed-off-by: Eduardo Morales <emoral435@gmail.com>

4 files changed, 139 insertions, 3 deletions

diff --git a/apps/files_versions/lib/Versions/IMetadataVersion.php b/apps/files_versions/lib/Versions/IMetadataVersion.php
new file mode 100644
index 00000000000..c11ec57f7d0
--- /dev/null
+++ b/apps/files_versions/lib/Versions/IMetadataVersion.php
@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2024 Eduardo Morales <emoral435@gmail.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Files_Versions\Versions;
+
+/**
+ * This interface allows for just direct accessing of the metadata column JSON
+ * @since 29.0.0
+ */
+interface IMetadataVersion {
+	/**
+	 * @abstract retrieves the metadata value from our $key param
+	 *
+	 * @param string $key the key for the json value of the metadata column
+	 * @since 29.0.0
+	 */
+	public function getMetadataValue(string $key): string;
+}
diff --git a/apps/files_versions/lib/Versions/IMetadataVersionBackend.php b/apps/files_versions/lib/Versions/IMetadataVersionBackend.php
new file mode 100644
index 00000000000..b67ead12955
--- /dev/null
+++ b/apps/files_versions/lib/Versions/IMetadataVersionBackend.php
@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2024 Eduardo Morales <emoral435@gmail.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Files_Versions\Versions;
+
+use OCP\Files\Node;
+
+/**
+ * This interface edits the metadata column of a node.
+ * Each column of the metadata has a key => value mapping.
+ * @since 29.0.0
+ */
+interface IMetadataVersionBackend {
+	/**
+	 * Sets a key value pair in the metadata column corresponding to the node's version.
+	 *
+	 * @param Node $node the node that triggered the Metadata event listener, aka, the file version
+	 * @param string $key the key for the json value of the metadata column
+	 * @param string $value the value that corresponds to the key in the metadata column
+	 * @since 29.0.0
+	 */
+	public function setMetadataValue(Node $node, string $key, string $value): void;
+
+	/**
+	 * Retrieves a corresponding value from the metadata column using the key.
+	 *
+	 * @param Node $node the node that triggered the Metadata event listener, aka, the file version
+	 * @param string $key the key for the json value of the metadata column
+	 * @since 29.0.0
+	 */
+	public function getMetadataValue(Node $node, string $key): ?string;
+}
diff --git a/apps/files_versions/lib/Versions/LegacyVersionsBackend.php b/apps/files_versions/lib/Versions/LegacyVersionsBackend.php
index 676a9d5a964..6c052b30591 100644
--- a/apps/files_versions/lib/Versions/LegacyVersionsBackend.php
+++ b/apps/files_versions/lib/Versions/LegacyVersionsBackend.php
@@ -39,13 +39,14 @@ use OCP\Files\FileInfo;
 use OCP\Files\Folder;
 use OCP\Files\IMimeTypeLoader;
 use OCP\Files\IRootFolder;
+use OCP\Files\Node;
 use OCP\Files\NotFoundException;
 use OCP\Files\Storage\IStorage;
 use OCP\IUser;
 use OCP\IUserManager;
 use OCP\IUserSession;
 
-class LegacyVersionsBackend implements IVersionBackend, INameableVersionBackend, IDeletableVersionBackend, INeedSyncVersionBackend {
+class LegacyVersionsBackend implements IVersionBackend, INameableVersionBackend, IDeletableVersionBackend, INeedSyncVersionBackend, IMetadataVersionBackend {
 	private IRootFolder $rootFolder;
 	private IUserManager $userManager;
 	private VersionsMapper $versionsMapper;
@@ -312,4 +313,33 @@ class LegacyVersionsBackend implements IVersionBackend, INameableVersionBackend,
 
 		return ($sourceFile->getPermissions() & $permissions) === $permissions;
 	}
+
+	public function setMetadataValue(Node $node, string $key, string $value): void {
+		// Do not handle folders.
+		if ($node instanceof File) {
+
+			try {
+				$versionEntity = $this->versionsMapper->findVersionForFileId($node->getId(), $node->getMTime());
+			} catch (\Exception $e) {
+				throw $e; // the version does not exist or too many versions exist
+			}
+
+			$currentMetadata = $versionEntity->getMetadata() ?? [];
+	
+			$currentMetadata[$key] = $value;
+			$versionEntity->setMetadata($currentMetadata);
+			$this->versionsMapper->update($versionEntity);
+		}
+
+	}
+
+	public function getMetadataValue(Node $node, string $key): ?string {
+		try {
+			$versionEntity = $this->versionsMapper->findVersionForFileId($node->getId(), $node->getMTime());
+			return $versionEntity->getMetadataValue($key);
+		} catch (\InvalidArgumentException $e) {
+			// we tried to find a version or key that doesn't exist
+			return null;
+		}
+	}
 }
diff --git a/apps/files_versions/lib/Versions/VersionManager.php b/apps/files_versions/lib/Versions/VersionManager.php
index 5fbfaae4a16..d884ffb0f7b 100644
--- a/apps/files_versions/lib/Versions/VersionManager.php
+++ b/apps/files_versions/lib/Versions/VersionManager.php
@@ -31,11 +31,12 @@ use OCP\Files\IRootFolder;
 use OCP\Files\Lock\ILock;
 use OCP\Files\Lock\ILockManager;
 use OCP\Files\Lock\LockContext;
+use OCP\Files\Node;
 use OCP\Files\Storage\IStorage;
 use OCP\IUser;
 use OCP\Lock\ManuallyLockedException;
 
-class VersionManager implements IVersionManager, INameableVersionBackend, IDeletableVersionBackend, INeedSyncVersionBackend {
+class VersionManager implements IVersionManager, INameableVersionBackend, IDeletableVersionBackend, INeedSyncVersionBackend, IMetadataVersionBackend {
 	/** @var (IVersionBackend[])[] */
 	private $backends = [];
 
@@ -160,6 +161,21 @@ class VersionManager implements IVersionManager, INameableVersionBackend, IDelet
 		}
 	}
 
+	public function setMetadataValue(Node $node, string $key, string $value): void {
+		$backend = $this->getBackendForStorage($node->getStorage());
+		if ($backend instanceof IMetadataVersionBackend) {
+			$backend->setMetadataValue($node, $key, $value);
+		}
+	}
+
+	public function getMetadataValue(Node $node, string $key): ?string {
+		$backend = $this->getBackendForStorage($node->getStorage());
+		if ($backend instanceof IMetadataVersionBackend) {
+			return $backend->getMetadataValue($node, $key);
+		}
+		return null;
+	}
+
 	/**
 	 * Catch ManuallyLockedException and retry in app context if possible.
 	 *
@@ -184,7 +200,7 @@ class VersionManager implements IVersionManager, INameableVersionBackend, IDelet
 			return $callback();
 		} catch (ManuallyLockedException $e) {
 			$owner = (string) $e->getOwner();
-			$appsThatHandleUpdates = array("text", "richdocuments");
+			$appsThatHandleUpdates = ["text", "richdocuments"];
 			if (!in_array($owner, $appsThatHandleUpdates)) {
 				throw $e;
 			}