/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
using System;
using System.IO;
using System.Messaging;

namespace Apache.NMS.MSMQ
{
	public class DefaultMessageConverter : IMessageConverter
	{
		public virtual Message ToMsmqMessage(IMessage message)
		{
			Message answer = new Message();
			ConvertMessageBodyToMSMQ(message, answer);
			MessageQueue responseQueue = null;
			if(message.NMSReplyTo != null)
			{
				IDestination destination = message.NMSReplyTo;
				responseQueue = ToMsmqDestination(destination);
			}

			if(message.NMSTimeToLive != TimeSpan.Zero)
			{
				answer.TimeToBeReceived = message.NMSTimeToLive;
			}

			if(message.NMSCorrelationID != null)
			{
				answer.CorrelationId = message.NMSCorrelationID;
			}

			answer.Recoverable = (message.NMSDeliveryMode == MsgDeliveryMode.Persistent);
			answer.Priority = ToMessagePriority(message.NMSPriority);
			answer.ResponseQueue = responseQueue;
			if(message.NMSType != null)
			{
				answer.Label = message.NMSType;
			}
			
			return answer;
		}

		private static MessagePriority ToMessagePriority(MsgPriority msgPriority)
		{
			switch(msgPriority)
			{
			case MsgPriority.Lowest:
				return MessagePriority.Lowest;

			case MsgPriority.VeryLow:
				return MessagePriority.VeryLow;

			case MsgPriority.Low:
			case MsgPriority.AboveLow:
				return MessagePriority.Low;

			default:
			case MsgPriority.BelowNormal:
			case MsgPriority.Normal:
				return MessagePriority.Normal;

			case MsgPriority.AboveNormal:
				return MessagePriority.AboveNormal;

			case MsgPriority.High:
				return MessagePriority.High;

			case MsgPriority.VeryHigh:
				return MessagePriority.VeryHigh;

			case MsgPriority.Highest:
				return MessagePriority.Highest;
			}
		}

		protected virtual void ConvertMessageBodyToMSMQ(IMessage message,
														Message answer)
		{
			if(message is IBytesMessage)
			{
				byte[] bytes = (message as IBytesMessage).Content;
				answer.BodyStream.Write(bytes, 0, bytes.Length);
			}
			else
			{
				throw new Exception("unhandled message type");
			}
		}

		public virtual IMessage ToNmsMessage(Message message)
		{
			BaseMessage answer = CreateNmsMessage(message);
			answer.NMSMessageId = message.Id;
			try
			{
				answer.NMSCorrelationID = message.CorrelationId;
			}
			catch(InvalidOperationException)
			{
			}

			try
			{
				answer.NMSDestination = ToNmsDestination(message.DestinationQueue);
			}
			catch(InvalidOperationException)
			{
			}

			answer.NMSType = message.Label;
			answer.NMSReplyTo = ToNmsDestination(message.ResponseQueue);
			try
			{
				answer.NMSTimeToLive = message.TimeToBeReceived;
			}
			catch(InvalidOperationException)
			{
			}
			return answer;
		}


		public MessageQueue ToMsmqDestination(IDestination destination)
		{
			return new MessageQueue((destination as Destination).Path);
		}

		protected virtual IDestination ToNmsDestination(MessageQueue destinationQueue)
		{
			if(destinationQueue == null)
			{
				return null;
			}
			return new Queue(destinationQueue.Path);
		}

		protected virtual BaseMessage CreateNmsMessage(Message message)
		{
			Stream stream = message.BodyStream;
			if(stream == null || stream.Length == 0)
			{
				return new BaseMessage();
			}
			byte[] buf = new byte[stream.Length];
			stream.Read(buf, 0, buf.Length);
			// TODO: how to recognise other flavors of message?
			BytesMessage result = new BytesMessage();
			result.Content = buf;
			return result;
		}
	}
}