protected async Task SendAsync()

in src/MessageProducer.cs [216:300]
65 lines of code
12 McCabe index (conditional complexity)

		protected async Task SendAsync(IDestination destination, IMessage message, MsgDeliveryMode deliveryMode, MsgPriority priority, TimeSpan timeToLive, bool specifiedTimeToLive)
		{
			if(null == destination)
			{
				// See if this producer was created without a destination.
				if(null == info.Destination)
				{
					throw new NotSupportedException();
				}

				// The producer was created with a destination, but an invalid destination
				// was specified.
				throw new Apache.NMS.InvalidDestinationException();
			}

			ActiveMQDestination dest = null;

			if(destination == this.info.Destination)
			{
				dest = destination as ActiveMQDestination;
			}
			else if(info.Destination == null)
			{
				dest = ActiveMQDestination.Transform(destination);
			}
			else
			{
				throw new NotSupportedException("This producer can only send messages to: " + this.info.Destination.PhysicalName);
			}

			if(this.ProducerTransformer != null)
			{
				IMessage transformed = this.ProducerTransformer(this.session, this, message);
				if(transformed != null)
				{
					message = transformed;
				}
			}

			ActiveMQMessage activeMessage = this.messageTransformation.TransformMessage<ActiveMQMessage>(message);

			activeMessage.ProducerId = info.ProducerId;
			activeMessage.Destination = dest;
			activeMessage.NMSDeliveryMode = deliveryMode;
			activeMessage.NMSPriority = priority;

			// Always set the message Id regardless of the disable flag.
			MessageId id = new MessageId();
			id.ProducerId = info.ProducerId;
			id.ProducerSequenceId = Interlocked.Increment(ref this.producerSequenceId);
			activeMessage.MessageId = id;
			
			// Ensure that the source message contains the NMSMessageId of the transformed
			// message for correlation purposes.
			if (!ReferenceEquals(message, activeMessage))
			{
				message.NMSMessageId = activeMessage.NMSMessageId;				
			}

			if(!disableMessageTimestamp)
			{
				activeMessage.NMSTimestamp = DateTime.UtcNow;
			}

			if(specifiedTimeToLive)
			{
				activeMessage.NMSTimeToLive = timeToLive;
			}

			// Ensure there's room left to send this message
			if(this.usage != null)
			{
				usage.WaitForSpace();
			}

			using(await closedLock.LockAsync().Await())
			{
				if(closed)
				{
					throw new ConnectionClosedException();
				}

				await session.DoSendAsync(dest, activeMessage, this, this.usage, this.RequestTimeout).Await();
			}
		}