fix(note-to-self): Prevent creating duplicate "Note to self" conversa…

lib/Participant.php

@@ -93,6 +93,10 @@ public function hasModeratorPermissions(bool $guestModeratorAllowed = true): boo
 	}
 
 	public function canStartCall(IConfig $config): bool {
+		if ($this->room->getType() === Room::TYPE_NOTE_TO_SELF) {
+			return false;
+		}
+
 		$defaultStartCall = (int) $config->getAppValue('spreed', 'start_calls', (string) Room::START_CALL_EVERYONE);
 
 		if ($defaultStartCall === Room::START_CALL_NOONE) {

lib/Service/NoteToSelfService.php

@@ -31,6 +31,8 @@
 use OCP\IL10N;
 use OCP\IUser;
 use OCP\IUserManager;
+use OCP\PreConditionNotMetException;
+use OCP\Security\ISecureRandom;
 
 class NoteToSelfService {
 	public function __construct(
@@ -40,6 +42,7 @@ public function __construct(
 		protected RoomService $roomService,
 		protected AvatarService $avatarService,
 		protected ParticipantService $participantService,
+		protected ISecureRandom $secureRandom,
 		protected IL10N $l,
 	) {
 	}
@@ -60,7 +63,7 @@ public function ensureNoteToSelfExistsForUser(string $userId): Room {
 			throw new \InvalidArgumentException('User not found');
 		}
 
-		return $this->createNoteToSelfConversation($currentUser);
+		return $this->createNoteToSelfConversation($currentUser, $noteToSelfId);
 	}
 
 	public function initialCreateNoteToSelfForUser(string $userId): void {
@@ -69,23 +72,42 @@ public function initialCreateNoteToSelfForUser(string $userId): void {
 			return;
 		}
 
+		// Prefixing with zz, so that casting to int does not give a random roomId for other requests
+		$randomLock = 'zz' . $this->secureRandom->generate(3);
+		$this->config->setUserValue($userId, 'spreed', 'note_to_self', $randomLock);
+
 		$currentUser = $this->userManager->get($userId);
 		if (!$currentUser instanceof IUser) {
 			throw new \InvalidArgumentException('User not found');
 		}
 
-		$this->createNoteToSelfConversation($currentUser);
+		$this->createNoteToSelfConversation($currentUser, $randomLock);
 	}
 
-	protected function createNoteToSelfConversation(IUser $user): Room {
+	protected function createNoteToSelfConversation(IUser $user, string|int $previousValue): Room {
 		$room = $this->roomService->createConversation(
 			Room::TYPE_NOTE_TO_SELF,
 			$this->l->t('Note to self'),
 			$user,
 			'note_to_self',
 			$user->getUID()
 		);
-		$this->config->setUserValue($user->getUID(), 'spreed', 'note_to_self', (string) $room->getId());
+
+		try {
+			$this->config->setUserValue($user->getUID(), 'spreed', 'note_to_self', (string) $room->getId(), (string) $previousValue);
+		} catch (PreConditionNotMetException $e) {
+			// This process didn't win the race for creating the conversation, so fetch the other one
+			$this->roomService->deleteRoom($room);
+
+			// This is a little trick to bypass local caching
+			$values = $this->config->getUserValueForUsers('spreed', 'note_to_self', [$user->getUID()]);
+			if (isset($values[$user->getUID()])) {
+				return $this->manager->getRoomById($values[$user->getUID()]);
+			}
+
+			// Failed to read parallel note-to-self creation
+			throw new RoomNotFoundException('Failed due to parallel requests');
+		}
 
 		$this->roomService->setDescription(
 			$room,

lib/Service/RoomFormatter.php

@@ -300,7 +300,7 @@ public function formatRoomV4(
 				$roomData['canDeleteConversation'] = $room->getType() !== Room::TYPE_ONE_TO_ONE
 					&& $room->getType() !== Room::TYPE_ONE_TO_ONE_FORMER
 					&& $currentParticipant->hasModeratorPermissions(false);
-				$roomData['canLeaveConversation'] = true;
+				$roomData['canLeaveConversation'] = $room->getType() !== Room::TYPE_NOTE_TO_SELF;
 				$roomData['canEnableSIP'] =
 					$this->talkConfig->isSIPConfigured()
 					&& !preg_match(Room::SIP_INCOMPATIBLE_REGEX, $room->getToken())