refactor: remove SystemTag logic from Folder into QuerySearchHelper

- adds OC\SystemTag\SystemTagsInFilesDetector where the search logic is
  moved to

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

1 files changed, 68 insertions, 0 deletions

diff --git a/lib/private/SystemTag/SystemTagsInFilesDetector.php b/lib/private/SystemTag/SystemTagsInFilesDetector.php
new file mode 100644
index 00000000000..0fcd7e051f6
--- /dev/null
+++ b/lib/private/SystemTag/SystemTagsInFilesDetector.php
@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\SystemTag;
+
+use OC\Files\Cache\QuerySearchHelper;
+use OC\Files\Node\Root;
+use OC\Files\Search\SearchComparison;
+use OC\Files\Search\SearchQuery;
+use OCP\Files\Folder;
+use OCP\Files\Search\ISearchComparison;
+
+class SystemTagsInFilesDetector {
+	public function __construct(protected QuerySearchHelper $searchHelper) {
+	}
+
+	public function detectAssignedSystemTagsIn(
+		Folder $folder,
+		string $filteredMediaType = '',
+		int $limit = 0,
+		int $offset = 0
+	): array {
+		// Currently query has to have exactly one search condition. If no media type is provided,
+		// we fall back to the presence of a system tag.
+		if (empty($filteredMediaType)) {
+			$query = new SearchQuery(new SearchComparison(ISearchComparison::COMPARE_LIKE, 'systemtag', '%'), $limit, $offset, []);
+		} else {
+			$query = new SearchQuery(new SearchComparison(ISearchComparison::COMPARE_LIKE, 'mimetype', $filteredMediaType . '/%'), $limit, $offset, []);
+		}
+		[$caches, ] = $this->searchHelper->getCachesAndMountPointsForSearch(
+			$this->getRootFolder($folder),
+			$folder->getPath(),
+		);
+		return $this->searchHelper->findUsedTagsInCaches($query, $caches);
+	}
+
+	protected function getRootFolder(?Folder $folder): Root {
+		if ($folder instanceof Root) {
+			return $folder;
+		} elseif ($folder === null) {
+			throw new \LogicException('Could not climb up to root folder');
+		}
+		return $this->getRootFolder($folder->getParent());
+	}
+}