1 files changed, 137 insertions, 0 deletions
diff --git a/lib/private/TagManager.php b/lib/private/TagManager.php
new file mode 100644
index 00000000000..5c346e14430
--- /dev/null
+++ b/lib/private/TagManager.php
@@ -0,0 +1,137 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC;
+
+use OC\Tagging\TagMapper;
+use OCP\Db\Exception as DBException;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\EventDispatcher\IEventListener;
+use OCP\IDBConnection;
+use OCP\ITagManager;
+use OCP\ITags;
+use OCP\IUserSession;
+use OCP\User\Events\UserDeletedEvent;
+use Psr\Log\LoggerInterface;
+
+/**
+ * @template-implements IEventListener<UserDeletedEvent>
+ */
+class TagManager implements ITagManager, IEventListener {
+
+	public function __construct(
+		private TagMapper $mapper,
+		private IUserSession $userSession,
+		private IDBConnection $connection,
+		private LoggerInterface $logger,
+		private IEventDispatcher $dispatcher,
+	) {
+	}
+
+	/**
+	 * Create a new \OCP\ITags instance and load tags from db.
+	 *
+	 * @see \OCP\ITags
+	 * @param string $type The type identifier e.g. 'contact' or 'event'.
+	 * @param array $defaultTags An array of default tags to be used if none are stored.
+	 * @param boolean $includeShared Whether to include tags for items shared with this user by others.
+	 * @param string $userId user for which to retrieve the tags, defaults to the currently
+	 *                       logged in user
+	 * @return \OCP\ITags
+	 *
+	 * since 20.0.0 $includeShared isn't used anymore
+	 */
+	public function load($type, $defaultTags = [], $includeShared = false, $userId = null) {
+		if (is_null($userId)) {
+			$user = $this->userSession->getUser();
+			if ($user === null) {
+				// nothing we can do without a user
+				return null;
+			}
+			$userId = $this->userSession->getUser()->getUId();
+		}
+		return new Tags($this->mapper, $userId, $type, $this->logger, $this->connection, $this->dispatcher, $this->userSession, $defaultTags);
+	}
+
+	/**
+	 * Get all users who favorited an object
+	 *
+	 * @param string $objectType
+	 * @param int $objectId
+	 * @return array
+	 */
+	public function getUsersFavoritingObject(string $objectType, int $objectId): array {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('uid')
+			->from('vcategory_to_object', 'o')
+			->innerJoin('o', 'vcategory', 'c', $query->expr()->eq('o.categoryid', 'c.id'))
+			->where($query->expr()->eq('objid', $query->createNamedParameter($objectId, IQueryBuilder::PARAM_INT)))
+			->andWhere($query->expr()->eq('c.type', $query->createNamedParameter($objectType)))
+			->andWhere($query->expr()->eq('c.category', $query->createNamedParameter(ITags::TAG_FAVORITE)));
+
+		$result = $query->execute();
+		$users = $result->fetchAll(\PDO::FETCH_COLUMN);
+		$result->closeCursor();
+
+		return $users;
+	}
+
+	public function handle(Event $event): void {
+		if (!($event instanceof UserDeletedEvent)) {
+			return;
+		}
+
+		// Find all objectid/tagId pairs.
+		$user = $event->getUser();
+		$qb = $this->connection->getQueryBuilder();
+		$qb->select('id')
+			->from('vcategory')
+			->where($qb->expr()->eq('uid', $qb->createNamedParameter($user->getUID())));
+		try {
+			$result = $qb->executeQuery();
+		} catch (DBException $e) {
+			$this->logger->error($e->getMessage(), [
+				'app' => 'core',
+				'exception' => $e,
+			]);
+			return;
+		}
+
+		$tagsIds = array_map(fn (array $row) => (int)$row['id'], $result->fetchAll());
+		$result->closeCursor();
+
+		if (count($tagsIds) === 0) {
+			return;
+		}
+
+		// Clean vcategory_to_object table
+		$qb = $this->connection->getQueryBuilder();
+		$qb = $qb->delete('vcategory_to_object')
+			->where($qb->expr()->in('categoryid', $qb->createParameter('chunk')));
+
+		// Clean vcategory
+		$qb1 = $this->connection->getQueryBuilder();
+		$qb1 = $qb1->delete('vcategory')
+			->where($qb1->expr()->in('uid', $qb1->createParameter('chunk')));
+
+		foreach (array_chunk($tagsIds, 1000) as $tagChunk) {
+			$qb->setParameter('chunk', $tagChunk, IQueryBuilder::PARAM_INT_ARRAY);
+			$qb1->setParameter('chunk', $tagChunk, IQueryBuilder::PARAM_INT_ARRAY);
+			try {
+				$qb->executeStatement();
+				$qb1->executeStatement();
+			} catch (DBException $e) {
+				$this->logger->error($e->getMessage(), [
+					'app' => 'core',
+					'exception' => $e,
+				]);
+			}
+		}
+	}
+}