public override async Task WriteAsync()

in iothub/device/src/Transport/Mqtt/MqttIotHubAdapter.cs [164:224]
52 lines of code
12 McCabe index (conditional complexity)

        public override async Task WriteAsync(IChannelHandlerContext context, object data)
        {
            if (Logging.IsEnabled)
                Logging.Enter(this, context.Name, data, nameof(WriteAsync));

            try
            {
                if (IsInState(StateFlags.Closed))
                {
                    if (Logging.IsEnabled)
                        Logging.Error(this, "When writing data to the MQTT transport layer, it had already been closed.", nameof(WriteAsync));

                    throw new IotHubCommunicationException("MQTT is disconnected.");
                }

                if (data is Message message)
                {
                    await SendMessageAsync(context, message).ConfigureAwait(true);
                    return;
                }

                if (data is string packetIdString)
                {
                    await AcknowledgeAsync(context, packetIdString).ConfigureAwait(true);
                    return;
                }

                if (data is DisconnectPacket)
                {
                    await WriteMessageAsync(context, data, s_shutdownOnWriteErrorHandler).ConfigureAwait(true);
                    return;
                }

                if (data is SubscribePacket)
                {
                    await SubscribeAsync(context, data as SubscribePacket).ConfigureAwait(true);
                    return;
                }

                if (data is UnsubscribePacket)
                {
                    await UnSubscribeAsync(context, data as UnsubscribePacket).ConfigureAwait(true);
                    return;
                }

                throw new InvalidOperationException($"Unexpected data type: '{data.GetType().Name}'");
            }
            catch (Exception ex) when (!ex.IsFatal())
            {
                if (Logging.IsEnabled)
                    Logging.Error(this, $"Received a non-fatal exception while writing data to the MQTT transport layer; will shut down: {ex}", nameof(WriteAsync));

                ShutdownOnErrorAsync(context, ex);
                throw;
            }
            finally
            {
                if (Logging.IsEnabled)
                    Logging.Exit(this, context.Name, nameof(WriteAsync));
            }
        }