User restore by user id, backup:user:list (#22)

backup:user:restore <location> <uid> only said "is not a recorded user export": the argument
is the manifest path, which only backup:user:backup printed once. backup:user:list shows the
exports again; a bare user id works when that user has exactly one export, otherwise the error
lists them. The export is resolved before the replace confirmation.

Fixes #22

lib/Command/ListUserExports.php

@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Command;
+
+use OCA\NgBackup\Service\TargetService;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Helper\Table;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class ListUserExports extends Command {
+	public function __construct(
+		private TargetService $targets,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this->setName('backup:user:list')
+			->setDescription('List the user exports (backup:user:backup) on a location')
+			->addArgument('target', InputArgument::OPTIONAL, 'Location name or id (default: all)')
+			->addArgument('user', InputArgument::OPTIONAL, 'Only the exports of this user id')
+			->setHelp(<<<'HELP'
+The manifest column is what occ backup:user:restore expects. A safety export made by a restore
+with --mode=replace is listed here as well.
+
+Example:
+  occ backup:user:list offsite alice
+HELP);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$name = $input->getArgument('target');
+		$uid = $input->getArgument('user');
+		$rows = [];
+		try {
+			$targets = $name === null ? $this->targets->list() : [$this->targets->get($name)];
+			foreach ($targets as $t) {
+				foreach ($this->targets->repository($t)->listUserExports($uid) as $path) {
+					$parts = explode('/', $path, 3);
+					$user = $parts[1] ?? '';
+					$exportId = $parts[2] ?? '';
+					$time = \DateTimeImmutable::createFromFormat('Ymd\THis\Z', substr($exportId, 0, 16), new \DateTimeZone('UTC'));
+					$rows[] = [$t->getName(), $user, $time !== false ? $time->format('Y-m-d H:i') : '', $path];
+				}
+			}
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		if ($rows === []) {
+			$output->writeln('No user exports yet (occ backup:user:backup).');
+			return 0;
+		}
+		(new Table($output))->setHeaders(['location', 'user', 'date (UTC)', 'manifest'])->setRows($rows)->render();
+		return 0;
+	}
+}

lib/Command/RestoreUser.php

@@ -33,7 +33,7 @@ final class RestoreUser extends Command {
 		$this->setName('backup:user:restore')
 			->setDescription('Restore a user from a user_migration export (see backup:user:backup)')
 			->addArgument('target', InputArgument::REQUIRED, 'Location name or id')
-			->addArgument('manifest', InputArgument::REQUIRED, 'Manifest path printed by backup:user:backup (users/<uid>/<exportId>)')
+			->addArgument('manifest', InputArgument::REQUIRED, 'Manifest path printed by backup:user:backup (users/<uid>/<exportId>), or a user id with exactly one export')
 			->addOption('mode', 'm', InputOption::VALUE_REQUIRED, 'replace or as-backup', UserRestoreService::MODE_REPLACE)
 			->addOption('force', null, InputOption::VALUE_NONE, 'Replace an existing account without asking (required when not interactive)')
 			->addOption('install-user-migration', null, InputOption::VALUE_NONE, 'Install and enable user_migration if it is missing (non-interactive consent)')
@@ -45,16 +45,31 @@ Never imports over a live account. Modes:
              compare and transfer by hand; Nextcloud cannot rename a user id, so the backup gets
              the new name, never the existing account
 
+occ backup:user:list shows the exports on a location. A user id alone works when that user
+has exactly one export there; with more, the command lists them and you pass one.
+
 Example:
   occ backup:user:restore offsite users/alice/20261005T120000Z-ab12cd34
+  occ backup:user:restore offsite alice
   occ backup:user:restore offsite users/alice/20261005T120000Z-ab12cd34 --mode=as-backup
 HELP);
 	}
 
 	protected function execute(InputInterface $input, OutputInterface $output): int {
 		$mode = (string)$input->getOption('mode');
-		$uid = explode('/', (string)$input->getArgument('manifest'))[1] ?? '';
-		if ($mode === UserRestoreService::MODE_REPLACE && $uid !== '' && $this->userManager->userExists($uid) && !$input->getOption('force')) {
+		try {
+			$target = $this->targets->get($input->getArgument('target'));
+			$ref = (string)$input->getArgument('manifest');
+			$manifest = $this->targets->repository($target)->resolveUserExport($ref);
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		if ($manifest !== $ref) {
+			$output->writeln("Using $manifest.");
+		}
+		$uid = explode('/', $manifest)[1];
+		if ($mode === UserRestoreService::MODE_REPLACE && $this->userManager->userExists($uid) && !$input->getOption('force')) {
 			// Replace deletes the live account (after a safety export). Shares to others and data of
 			// apps without a user_migration migrator do not come back, so never do it unasked.
 			if (!$input->isInteractive()) {
@@ -69,9 +84,8 @@ HELP);
 		}
 		try {
 			$output->writeln('<comment>Note: on restore, user_migration only imports the app settings on its own allowlist (e.g. calendar view and reminder settings); other app settings of this user are skipped. Reason: NG Backup uses user_migration\'s importer; widening the list would mean building a settings importer of our own.</comment>');
-			$target = $this->targets->get($input->getArgument('target'));
 			$this->installer->ensureEnabled($input, $output);
-			$user = $this->userRestore->restoreUser($target, (string)$input->getArgument('manifest'), $mode);
+			$user = $this->userRestore->restoreUser($target, $manifest, $mode);
 		} catch (\Throwable $e) {
 			$output->writeln('<error>' . $e->getMessage() . '</error>');
 			return 1;

lib/Repository/Repository.php

@@ -561,6 +561,31 @@ final class Repository {
 		return isset($this->catalog->userExports[$manifestPath]);
 	}
 
+	/**
+	 * The recorded export $ref names: a manifest path (users/<uid>/<exportId>) as is, or a bare
+	 * user id (also "users/<uid>") when that user has exactly one export here. Anything else
+	 * throws, with the exports to choose from in the message.
+	 */
+	public function resolveUserExport(string $ref): string {
+		if ($this->isRecordedUserExport($ref)) {
+			return $ref;
+		}
+		$rest = trim($ref, '/');
+		if (str_starts_with($rest, 'users/')) {
+			$rest = substr($rest, strlen('users/'));
+		}
+		$uid = explode('/', $rest)[0];
+		$exports = $uid !== '' ? $this->listUserExports($uid) : [];
+		if (!str_contains($rest, '/') && count($exports) === 1) {
+			return $exports[0];
+		}
+		if ($exports === []) {
+			throw new RepositoryException("$ref is not a recorded user export for this location, and $uid has no exports here. Expected users/<uid>/<exportId>; occ backup:user:list shows the exports");
+		}
+		$which = str_contains($rest, '/') ? "$ref is not a recorded user export for this location" : "$uid has " . count($exports) . ' exports here';
+		throw new RepositoryException("$which; pass one of these (newest first):\n  " . implode("\n  ", $exports));
+	}
+
 	/** Permanently delete a user export. Its blobs are freed by the next prune() like any other. */
 	public function forgetUserExport(string $manifestPath): void {
 		if (!isset($this->catalog->userExports[$manifestPath])) {