Add command to get folders by tag

Fixes #3

appinfo/info.xml

@@ -20,5 +20,6 @@
     <commands>
 		<command>OCA\GroupfolderTags\Command\Tag</command>
 		<command>OCA\GroupfolderTags\Command\GetTag</command>
+		<command>OCA\GroupfolderTags\Command\GetFolder</command>
     </commands>
 </info>

lib/Command/GetFolder.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace OCA\GroupfolderTags\Command;
+
+use OCP\DB\Exception;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class GetFolder extends TagCommand {
+	protected function configure(): void {
+		$this
+			->setName('groupfolder-tags:get-folder')
+			->setDescription('Get Groupfolders with tag key optionally filtered by tag value.')
+			->addArgument('key', InputArgument::REQUIRED, 'Key of the tag')
+			->addArgument('value', InputArgument::OPTIONAL, 'Value of the tag');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$tagKey = $input->getArgument('key');
+		$tagValue = $input->getArgument('value');
+
+		try {
+			$results = $this->service->findFolder($tagKey, $tagValue);
+
+			if (empty($results)) {
+				$output->writeln("<error>Could not find Groupfolders for tag</error>");
+				return 1;
+			}
+
+			foreach ($results as $result) {
+				$folder = $this->folderManager->getFolder($result['group_folder_id'], $this->rootFolder->getMountPoint()->getNumericStorageId());
+				if ($folder === false) {
+					$output->writeln("<error>Folder not found: {$result['group_folder_id']}</error>");
+					continue;
+				}
+				$output->writeln(json_encode($folder));
+			}
+			return 0;
+		} catch (Exception $e) {
+			$output->writeln("<error>Exception \"{$e->getMessage()}\" at {$e->getFile()} line {$e->getLine()}</error>");
+			return 1;
+		}
+	}
+}

lib/Db/TagMapper.php

@@ -91,4 +91,20 @@ class TagMapper extends QBMapper {
 
 		return $this->findEntities($qb);
 	}
+
+	/**
+	 * @throws Exception
+	 */
+	public function findFolder(string $tagKey, ?string $tagValue): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->selectDistinct('group_folder_id')
+			->from(self::TABLENAME)
+			->where($qb->expr()->eq('tag_key', $qb->createNamedParameter($tagKey)));
+
+		if(isset($tagValue)) {
+			$qb->andWhere($qb->expr()->eq('tag_value', $qb->createNamedParameter($tagValue)));
+		}
+
+		return $qb->executeQuery()->fetchAll();
+	}
 }

lib/Service/TagService.php

@@ -78,4 +78,11 @@ class TagService {
 	public function findByGroupFolderAndKey(int $groupFolderId, ?string $key): array {
 		return $this->mapper->findByGroupFolderAndKey($groupFolderId, $key);
 	}
+
+	/**
+	 * @throws \OCP\DB\Exception
+	 */
+	public function findFolder(string $key, ?string $value): array {
+		return $this->mapper->findFolder($key, $value);
+	}
 }