public ActionResult <Chat> Create(Chat chat)
        {
            chatsService.Create(chat);

            return(CreatedAtRoute("GetChat", new { id = chat.Id.ToString() }, chat));
        }
        public async Task KafkaConsumer()
        {
            List <string>  topicListFromDB     = chatsService.GetTopics();
            ConsumerConfig config              = JsonConvert.DeserializeObject <ConsumerConfig>(System.IO.File.ReadAllText(Constant.ConsumerConfigFilePath));
            var            topicListFromServer = AdminClient.RemoveAdminTopics(AdminClient.getMetadata(Constant.BrokerIP));

            foreach (string topic in topicListFromServer)
            {
                if (!topicListFromDB.Contains(topic))
                {
                    Chat chat = new Chat(topic);
                    chatsService.Create(chat);
                }
            }

            using (var consumer = new ConsumerBuilder <Ignore, byte[]>(config).Build())
            {
                string fileName = "";
                consumer.Subscribe(topicListFromServer);
                CancellationTokenSource cts = new CancellationTokenSource();
                Console.CancelKeyPress += (_, e) =>
                {
                    e.Cancel = true; // prevent the process from terminating.
                    cts.Cancel();
                };

                try
                {
                    while (true)
                    {
                        try
                        {
                            var cr = consumer.Consume(cts.Token);
                            Console.WriteLine(cr.Topic);
                            // store the image
                            if (cr.Topic.Equals("FileContent"))
                            {
                                if (fileName != "")
                                {
                                    Console.WriteLine(cr.Value);
                                    FileStream   myFile   = System.IO.File.Open(@B3Image + fileName, FileMode.Create, FileAccess.Write);
                                    BinaryWriter myWriter = new BinaryWriter(myFile);
                                    myWriter.Write(cr.Value);
                                    myWriter.Close();
                                    myFile.Close();
                                    fileName = "";
                                }
                            }
                            else if (cr.Topic.Equals("FileName"))
                            {
                                fileName = Encoding.Default.GetString(cr.Value);
                            }
                            else
                            {
                                var incomming = new Chat();
                                try
                                {
                                    ChatLine chatPackage = JsonConvert.DeserializeObject <List <ChatLine> >(Encoding.Default.GetString(cr.Value)).First();
                                    incomming = new Chat(cr.Topic, chatPackage);
                                }
                                catch (Exception)
                                {
                                    Console.WriteLine("Deserialize failed, check MongoDB if it is delivered from CLI.");
                                    ChatLine chatPackage = new ChatLine(Encoding.Default.GetString(cr.Value), "CLTestUser");
                                    incomming = new Chat(cr.Topic, chatPackage);
                                }

                                if (topicListFromDB.Contains(cr.Topic))
                                {
                                    //Add new line to DB
                                    chatsService.UpdateByTopic(cr.Topic, incomming);
                                }
                                else
                                {
                                    //create new Topic
                                    chatsService.Create(incomming);
                                    topicListFromDB.Add(cr.Topic);
                                }

                                var allChats = JsonConvert.SerializeObject
                                               (
                                    chatsService.Get(),
                                    new JsonSerializerSettings {
                                    ContractResolver = new CamelCasePropertyNamesContractResolver()
                                }
                                               );
                                await chatHub.SendMessage(allChats);
                            }
                        }
                        catch (ConsumeException e)
                        {
                            Console.WriteLine($"Error occured: {e.Error.Reason}");
                        }
                    }
                }
                catch (OperationCanceledException)
                {
                    // Ensure the consumer leaves the group cleanly and final offsets are committed.
                    consumer.Close();
                }
            }
        }