1 files changed, 218 insertions, 0 deletions
diff --git a/apps/files_sharing/lib/SharesReminderJob.php b/apps/files_sharing/lib/SharesReminderJob.php
new file mode 100644
index 00000000000..9682f7fc770
--- /dev/null
+++ b/apps/files_sharing/lib/SharesReminderJob.php
@@ -0,0 +1,218 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\Files_Sharing;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\BackgroundJob\TimedJob;
+use OCP\Constants;
+use OCP\DB\Exception;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\Defaults;
+use OCP\Files\NotFoundException;
+use OCP\IDBConnection;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUserManager;
+use OCP\L10N\IFactory;
+use OCP\Mail\IEMailTemplate;
+use OCP\Mail\IMailer;
+use OCP\Share\Exceptions\ShareNotFound;
+use OCP\Share\IManager;
+use OCP\Share\IShare;
+use OCP\Util;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Send a reminder via email to the sharee(s) if the folder is still empty a predefined time before the expiration date
+ */
+class SharesReminderJob extends TimedJob {
+	private const SECONDS_BEFORE_REMINDER = 86400;
+	private const CHUNK_SIZE = 1000;
+
+	public function __construct(
+		ITimeFactory                     $time,
+		private readonly IDBConnection   $db,
+		private readonly IManager        $shareManager,
+		private readonly IUserManager    $userManager,
+		private readonly LoggerInterface $logger,
+		private readonly IURLGenerator   $urlGenerator,
+		private readonly IFactory        $l10nFactory,
+		private readonly IMailer         $mailer,
+		private readonly Defaults        $defaults,
+	) {
+		parent::__construct($time);
+		$this->setInterval(3600);
+	}
+
+
+	/**
+	 * Makes the background job do its work
+	 *
+	 * @param array $argument unused argument
+	 * @throws Exception if a database error occurs
+	 */
+	public function run(mixed $argument): void {
+		foreach ($this->getShares() as $share) {
+			$reminderInfo = $this->prepareReminder($share);
+			if ($reminderInfo !== null) {
+				$this->sendReminder($reminderInfo);
+			}
+		}
+	}
+
+	/**
+	 * Finds all shares of empty folders, for which the user has write permissions.
+	 * The returned shares are of type user or email only, have expiration dates within the specified time frame
+	 * and have not yet received a reminder.
+	 *
+	 * @return array<IShare>|\Iterator
+	 * @throws Exception if a database error occurs
+	 */
+	private function getShares(): array|\Iterator {
+		$minDate = new \DateTime();
+		$maxDate = new \DateTime();
+		$maxDate->setTimestamp($maxDate->getTimestamp() + self::SECONDS_BEFORE_REMINDER);
+
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('s.id', 's.share_type')
+			->from('share', 's')
+			->leftJoin('s', 'filecache', 'f', $qb->expr()->eq('f.parent', 's.file_source'))
+			->where(
+				$qb->expr()->andX(
+					$qb->expr()->orX(
+						$qb->expr()->eq('s.share_type', $qb->expr()->literal(IShare::TYPE_USER)),
+						$qb->expr()->eq('s.share_type', $qb->expr()->literal(IShare::TYPE_EMAIL))
+					),
+					$qb->expr()->eq('s.item_type', $qb->expr()->literal('folder')),
+					$qb->expr()->gte('s.expiration', $qb->createNamedParameter($minDate->format('Y-m-d H:i:s'))),
+					$qb->expr()->lt('s.expiration', $qb->createNamedParameter($maxDate->format('Y-m-d H:i:s'))),
+					$qb->expr()->eq('s.reminder_sent', $qb->createNamedParameter(
+						false, IQueryBuilder::PARAM_BOOL
+					)),
+					$qb->expr()->eq(
+						$qb->expr()->bitwiseAnd('s.permissions', Constants::PERMISSION_CREATE),
+						$qb->createNamedParameter(Constants::PERMISSION_CREATE, IQueryBuilder::PARAM_INT)
+					),
+					$qb->expr()->isNull('f.fileid')
+				)
+			)
+			->setMaxResults(SharesReminderJob::CHUNK_SIZE);
+
+		$sharesResult = $qb->executeQuery();
+		while ($share = $sharesResult->fetch()) {
+			if ((int)$share['share_type'] === IShare::TYPE_EMAIL) {
+				$id = "ocMailShare:$share[id]";
+			} else {
+				$id = "ocinternal:$share[id]";
+			}
+
+			try {
+				yield $this->shareManager->getShareById($id);
+			} catch (ShareNotFound) {
+				$this->logger->error("Share with ID $id not found.");
+			}
+		}
+		$sharesResult->closeCursor();
+	}
+
+	/**
+	 * Retrieves and returns all the necessary data before sending a reminder.
+	 * It also updates the reminder sent flag for the affected shares (to avoid multiple reminders).
+	 *
+	 * @param IShare $share Share that was obtained with {@link getShares}
+	 * @return array|null Info needed to send a reminder
+	 */
+	private function prepareReminder(IShare $share): array|null {
+		$sharedWith = $share->getSharedWith();
+		$reminderInfo = [];
+		if ($share->getShareType() == IShare::TYPE_USER) {
+			$user = $this->userManager->get($sharedWith);
+			if ($user === null) {
+				return null;
+			}
+			$reminderInfo['email'] = $user->getEMailAddress();
+			$reminderInfo['userLang'] = $this->l10nFactory->getUserLanguage($user);
+			$reminderInfo['folderLink'] = $this->urlGenerator->linkToRouteAbsolute('files.view.index', [
+				'dir' => $share->getTarget()
+			]);
+		} else {
+			$reminderInfo['email'] = $sharedWith;
+			$reminderInfo['folderLink'] = $this->urlGenerator->linkToRouteAbsolute('files_sharing.sharecontroller.showShare', [
+				'token' => $share->getToken()
+			]);
+		}
+		if (empty($reminderInfo['email'])) {
+			return null;
+		}
+
+		try {
+			$reminderInfo['folderName'] = $share->getNode()->getName();
+		} catch (NotFoundException) {
+			$id = $share->getFullId();
+			$this->logger->error("File by share ID $id not found.");
+		}
+		$share->setReminderSent(true);
+		$this->shareManager->updateShare($share);
+		return $reminderInfo;
+	}
+
+	/**
+	 * This method accepts data obtained by {@link prepareReminder} and sends reminder email.
+	 *
+	 * @param array $reminderInfo
+	 * @return void
+	 */
+	private function sendReminder(array $reminderInfo): void {
+		$instanceName = $this->defaults->getName();
+		$from = [Util::getDefaultEmailAddress($instanceName) => $instanceName];
+		$l = $this->l10nFactory->get('files_sharing', $reminderInfo['userLang'] ?? null);
+		$emailTemplate = $this->generateEMailTemplate($l, [
+			'link' => $reminderInfo['folderLink'], 'name' => $reminderInfo['folderName']
+		]);
+
+		$message = $this->mailer->createMessage();
+		$message->setFrom($from);
+		$message->setTo([$reminderInfo['email']]);
+		$message->useTemplate($emailTemplate);
+		$errorText = "Sending email with share reminder to $reminderInfo[email] failed.";
+		try {
+			$failedRecipients = $this->mailer->send($message);
+			if (count($failedRecipients) > 0) {
+				$this->logger->error($errorText);
+			}
+		} catch (\Exception) {
+			$this->logger->error($errorText);
+		}
+	}
+
+	/**
+	 * Returns the reminder email template
+	 *
+	 * @param IL10N $l
+	 * @param array $folder Folder the user should be reminded of
+	 * @return IEMailTemplate
+	 */
+	private function generateEMailTemplate(IL10N $l, array $folder): IEMailTemplate {
+		$emailTemplate = $this->mailer->createEMailTemplate('files_sharing.SharesReminder', [
+			'folder' => $folder,
+		]);
+		$emailTemplate->addHeader();
+		$emailTemplate->setSubject(
+			$l->t('Remember to upload the files to %s', [$folder['name']])
+		);
+		$emailTemplate->addBodyText($l->t(
+			'We would like to kindly remind you that you have not yet uploaded any files to the shared folder.'
+		));
+		$emailTemplate->addBodyButton(
+			$l->t('Open "%s"', [$folder['name']]),
+			$folder['link']
+		);
+		$emailTemplate->addFooter();
+		return $emailTemplate;
+	}
+}