Make the API work with timestamps

Signed-off-by: Joas Schilling <coding@schilljs.com>

docs/conversation.md

@@ -63,7 +63,7 @@ Base endpoint is: `/ocs/v2.php/apps/spreed/api/v1`
         `isFavorite` | bool | Flag if the conversation is favorited by the user
         `notificationLevel` | int | The notification level for the user (one of `Participant::NOTIFY_*` (1-3))
         `lobbyState` | int | Webinary lobby restriction (0-1), if the participant is a moderator they can always join the conversation (only available with `webinary-lobby` capability)
-        `lobbyTimer` | string | Datetime when the lobby will be automatically disabled ([Format: `Y-m-d\TH:i:sP`](https://www.php.net/manual/en/class.datetimeinterface.php#datetime.constants.atom)) (only available with `webinary-lobby` capability)
+        `lobbyTimer` | int | Timestamp when the lobby will be automatically disabled (only available with `webinary-lobby` capability)
         `unreadMessages` | int | Number of unread chat messages in the conversation (only available with `chat-v2` capability)
         `unreadMention` | bool | Flag if the user was mentioned since their last visit
         `lastReadMessage` | int | ID of the last read message in a room (only available with `chat-read-marker` capability)

docs/webinary.md

@@ -18,7 +18,7 @@ Base endpoint is: `/ocs/v2.php/apps/spreed/api/v1`
     field | type | Description
     ------|------|------------
     `state` | int | New state for the conversation
-    `timer` | string | Datetime when the lobby state is reset to all participants ([Format: `Y-m-d\TH:i:sP`](https://www.php.net/manual/en/class.datetimeinterface.php#datetime.constants.atom))
+    `timer` | int/null | Timestamp when the lobby state is reset to all participants
 
 * Response:
     - Header:

lib/Controller/RoomController.php

@@ -204,9 +204,9 @@ class RoomController extends AEnvironmentAwareController {
 
 		$lobbyTimer = $room->getLobbyTimer();
 		if ($lobbyTimer instanceof \DateTimeInterface) {
-			$lobbyTimer = $lobbyTimer->format(\DateTime::ATOM);
+			$lobbyTimer = $lobbyTimer->getTimestamp();
 		} else {
-			$lobbyTimer = '';
+			$lobbyTimer = 0;
 		}
 
 		$roomData = array_merge($roomData, [

lib/Controller/WebinaryController.php

@@ -46,14 +46,14 @@ class WebinaryController extends AEnvironmentAwareController {
 	 * @RequireModeratorParticipant
 	 *
 	 * @param int $state
-	 * @param string $timer
+	 * @param int|null $timer
 	 * @return DataResponse
 	 */
-	public function setLobby(int $state, ?string $timer = null): DataResponse {
+	public function setLobby(int $state, ?int $timer = null): DataResponse {
 		$timerDateTime = null;
-		if (trim((string) $timer) !== '') {
+		if ($timer !== null && $timer > 0) {
 			try {
-				$timerDateTime = $this->timeFactory->getDateTime($timer);
+				$timerDateTime = $this->timeFactory->getDateTime('@' . $timer);
 				$timerDateTime->setTimezone(new \DateTimeZone('UTC'));
 			} catch (\Exception $e) {
 				return new DataResponse([], Http::STATUS_BAD_REQUEST);