Add an endpoint to delete a message

For now it only creates a system message

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

appinfo/routes.php

@@ -153,6 +153,16 @@ return [
 				'token' => '^[a-z0-9]{4,30}$',
 			],
 		],
+		[
+			'name' => 'Chat#deleteMessage',
+			'url' => '/api/{apiVersion}/chat/{token}/{messageId}',
+			'verb' => 'DELETE',
+			'requirements' => [
+				'apiVersion' => 'v1',
+				'token' => '^[a-z0-9]{4,30}$',
+				'messageId' => '^[0-9]+$',
+			],
+		],
 		[
 			'name' => 'Chat#setReadMarker',
 			'url' => '/api/{apiVersion}/chat/{token}/read',

lib/Chat/ChatManager.php

@@ -247,6 +247,22 @@ class ChatManager {
 		return $comment;
 	}
 
+	/**
+	 * @param Room $chat
+	 * @param string $messageId
+	 * @return IComment
+	 * @throws NotFoundException
+	 */
+	public function getComment(Room $chat, string $messageId): IComment {
+		$comment = $this->commentsManager->get($messageId);
+
+		if ($comment->getObjectType() !== 'chat' || $comment->getObjectId() !== (string) $chat->getId()) {
+			throw new NotFoundException('Message not found in the right context');
+		}
+
+		return $comment;
+	}
+
 	public function getLastReadMessageFromLegacy(Room $chat, IUser $user): int {
 		$marker = $this->commentsManager->getReadMark('chat', $chat->getId(), $user);
 		if ($marker === null) {

lib/Chat/Parser/SystemMessage.php

@@ -354,6 +354,11 @@ class SystemMessage {
 			if ($currentUserIsActor) {
 				$parsedMessage = $this->l->t('You stopped Matterbridge.');
 			}
+		} elseif ($message === 'message_deleted') {
+			$parsedMessage = $this->l->t('{actor} deleted a message');
+			if ($currentUserIsActor) {
+				$parsedMessage = $this->l->t('You deleted a message');
+			}
 		} else {
 			throw new \OutOfBoundsException('Unknown subject');
 		}

lib/Controller/ChatController.php

@@ -462,6 +462,40 @@ class ChatController extends AEnvironmentAwareController {
 		return $response;
 	}
 
+	/**
+	 * @NoAdminRequired
+	 * @RequireParticipant
+	 *
+	 * @param int $messageId
+	 * @return DataResponse
+	 */
+	public function deleteMessage(int $messageId): DataResponse {
+		try {
+			$message = $this->chatManager->getComment($this->room, (string) $messageId);
+		} catch (NotFoundException $e) {
+			return new DataResponse([], Http::STATUS_NOT_FOUND);
+		}
+
+		$attendee = $this->participant->getAttendee();
+		if (!$this->participant->hasModeratorPermissions(false)
+			&& ($message->getActorType() !== $attendee->getActorType()
+				|| $message->getActorId() !== $attendee->getActorId())) {
+			// Actor is not a moderator or not the owner of the message
+			return new DataResponse([], Http::STATUS_FORBIDDEN);
+		}
+
+		$this->chatManager->addSystemMessage(
+			$this->room,
+			$attendee->getActorType(),
+			$attendee->getActorId(),
+			json_encode(['message' => 'message_deleted', 'parameters' => ['message' => $messageId]]),
+			$this->timeFactory->getDateTime(),
+			false
+		);
+
+		return new DataResponse();
+	}
+
 	/**
 	 * @NoAdminRequired
 	 * @RequireParticipant