Allow to force rename a conflicting calendar

apps/dav/lib/CalDAV/CalDavBackend.php

@@ -2744,11 +2744,13 @@ public function purgeAllCachedEventsForSubscription($subscriptionId) {
 	 * @param string $uriName
 	 * @param string $uriOrigin
 	 * @param string $uriDestination
+	 * @param string $newUriName (optional) the new uriName
 	 */
-	public function moveCalendar($uriName, $uriOrigin, $uriDestination) {
+	public function moveCalendar($uriName, $uriOrigin, $uriDestination, $newUriName = null) {
 		$query = $this->db->getQueryBuilder();
 		$query->update('calendars')
 			->set('principaluri', $query->createNamedParameter($uriDestination))
+			->set('uri', $query->createNamedParameter($newUriName ?: $uriName))
 			->where($query->expr()->eq('principaluri', $query->createNamedParameter($uriOrigin)))
 			->andWhere($query->expr()->eq('uri', $query->createNamedParameter($uriName)))
 			->execute();

apps/dav/lib/Command/MoveCalendar.php

@@ -104,7 +104,7 @@ protected function configure() {
 			->addArgument('destinationuid',
 				InputArgument::REQUIRED,
 				'User who will receive the calendar')
-			->addOption('force', 'f', InputOption::VALUE_NONE, "Force the migration by removing existing shares");
+			->addOption('force', 'f', InputOption::VALUE_NONE, "Force the migration by removing existing shares and renaming calendars in case of conflicts");
 	}
 
 	protected function execute(InputInterface $input, OutputInterface $output): int {
@@ -122,34 +122,93 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 		}
 
 		$name = $input->getArgument('name');
+		$newName = null;
 
 		$calendar = $this->calDav->getCalendarByUri(self::URI_USERS . $userOrigin, $name);
 
 		if (null === $calendar) {
 			throw new \InvalidArgumentException("User <$userOrigin> has no calendar named <$name>. You can run occ dav:list-calendars to list calendars URIs for this user.");
 		}
 
-		if (null !== $this->calDav->getCalendarByUri(self::URI_USERS . $userDestination, $name)) {
-			throw new \InvalidArgumentException("User <$userDestination> already has a calendar named <$name>.");
+		// Calendar already exists
+		if ($this->calendarExists($userDestination, $name)) {
+			if ($input->getOption('force')) {
+				// Try to find a suitable name
+				$newName = $this->getNewCalendarName($userDestination, $name);
+
+				// If we didn't find a suitable value after all the iterations, give up
+				if ($this->calendarExists($userDestination, $newName)) {
+					throw new \InvalidArgumentException("Unable to find a suitable calendar name for <$userDestination> with initial name <$name>.");
+				}
+			} else {
+				throw new \InvalidArgumentException("User <$userDestination> already has a calendar named <$name>.");
+			}
 		}
 
-		$this->checkShares($calendar, $userOrigin, $userDestination, $input->getOption('force'));
+		$hadShares = $this->checkShares($calendar, $userOrigin, $userDestination, $input->getOption('force'));
+		if ($hadShares) {
+			/**
+			 * Warn that share links have changed if there are shares
+			 */
+			$this->io->note([
+				"Please note that moving calendar " . $calendar['uri'] . " from user <$userOrigin> to <$userDestination> has caused share links to change.",
+				"Sharees will need to change \"example.com/remote.php/dav/calendars/uid/" . $calendar['uri'] . "_shared_by_$userOrigin\" to \"example.com/remote.php/dav/calendars/uid/" . $newName ?: $calendar['uri'] . "_shared_by_$userDestination\""
+			]);
+		}
 
-		$this->calDav->moveCalendar($name, self::URI_USERS . $userOrigin, self::URI_USERS . $userDestination);
+		$this->calDav->moveCalendar($name, self::URI_USERS . $userOrigin, self::URI_USERS . $userDestination, $newName);
 
-		$this->io->success("Calendar <$name> was moved from user <$userOrigin> to <$userDestination>");
+		$this->io->success("Calendar <$name> was moved from user <$userOrigin> to <$userDestination>" . ($newName ? " as <$newName>" : ''));
 		return 0;
 	}
 
+	/**
+	 * Check if the calendar exists for user
+	 *
+	 * @param string $userDestination
+	 * @param string $name
+	 * @return bool
+	 */
+	protected function calendarExists(string $userDestination, string $name): bool {
+		return null !== $this->calDav->getCalendarByUri(self::URI_USERS . $userDestination, $name);
+	}
+
+	/**
+	 * Try to find a suitable new calendar name that
+	 * doesn't exists for the provided user
+	 *
+	 * @param string $userDestination
+	 * @param string $name
+	 * @return string
+	 */
+	protected function getNewCalendarName(string $userDestination, string $name): string {
+		$increment = 1;
+		$newName = $name . '-' . $increment;
+		while ($increment <= 10) {
+			$this->io->writeln("Trying calendar name <$newName>", OutputInterface::VERBOSITY_VERBOSE);
+			if (!$this->calendarExists($userDestination, $newName)) {
+				// New name is good to go
+				$this->io->writeln("Found proper new calendar name <$newName>", OutputInterface::VERBOSITY_VERBOSE);
+				break;
+			}
+			$newName = $name . '-' . $increment;
+			$increment++;
+		}
+
+		return $newName;
+	}
+
 	/**
 	 * Check that moving the calendar won't break shares
 	 *
 	 * @param array $calendar
 	 * @param string $userOrigin
 	 * @param string $userDestination
 	 * @param bool $force
+	 * @return bool had any shares or not
+	 * @throws \InvalidArgumentException
 	 */
-	private function checkShares(array $calendar, string $userOrigin, string $userDestination, bool $force = false) {
+	private function checkShares(array $calendar, string $userOrigin, string $userDestination, bool $force = false): bool {
 		$shares = $this->calDav->getShares($calendar['id']);
 		foreach ($shares as $share) {
 			list(, $prefix, $userOrGroup) = explode('/', $share['href'], 3);
@@ -177,14 +236,7 @@ private function checkShares(array $calendar, string $userOrigin, string $userDe
 				}
 			}
 		}
-		/**
-		 * Warn that share links have changed if there are shares
-		 */
-		if (count($shares) > 0) {
-			$this->io->note([
-				"Please note that moving calendar " . $calendar['uri'] . " from user <$userOrigin> to <$userDestination> has caused share links to change.",
-				"Sharees will need to change \"example.com/remote.php/dav/calendars/uid/" . $calendar['uri'] . "_shared_by_$userOrigin\" to \"example.com/remote.php/dav/calendars/uid/" . $calendar['uri'] . "_shared_by_$userDestination\""
-			]);
-		}
+
+		return count($shares) > 0;
 	}
 }