Add version handling to IMigrator

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

lib/public/UserMigration/IMigrator.php

@@ -6,6 +6,7 @@ declare(strict_types=1);
  * @copyright 2022 Christopher Ng <chrng8@gmail.com>
  *
  * @author Christopher Ng <chrng8@gmail.com>
+ * @author Côme Chilliet <come.chilliet@nextcloud.com>
  *
  * @license GNU AGPL version 3 or any later version
  *
@@ -55,4 +56,18 @@ interface IMigrator {
 		IImportSource $importSource,
 		OutputInterface $output
 	): void;
+
+	/**
+	 * Returns the version of the export format for this migrator
+	 *
+	 * @since 24.0.0
+	 */
+	public function getVersion(): int;
+
+	/**
+	 * Checks whether it is able to import a version of the export format for this migrator
+	 *
+	 * @since 24.0.0
+	 */
+	public function canImport(int $version): bool;
 }

lib/public/UserMigration/TMigratorBasicVersionHandling.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2022 Côme Chilliet <come.chilliet@nextcloud.com>
+ *
+ * @author Côme Chilliet <come.chilliet@nextcloud.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 OCP\UserMigration;
+
+/**
+ * Basic version handling: we can import older versions but not newer ones
+ */
+trait TMigratorBasicVersionHandling {
+	protected int $version = 1;
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getVersion(): int {
+		return $this->version;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function canImport(int $version): bool {
+		return ($this->version >= $version);
+	}
+}