/*
 * 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 Apache.NMS.Stomp.Commands;
using Apache.NMS.Util;

namespace Apache.NMS.Stomp.State
{
	public class ConnectionState
	{

		ConnectionInfo info;
		private readonly AtomicDictionary<ConsumerId, ConsumerState> consumers = new AtomicDictionary<ConsumerId, ConsumerState>();
		private readonly Atomic<bool> _shutdown = new Atomic<bool>(false);

		public ConnectionState(ConnectionInfo info)
		{
			this.info = info;
		}

		public override String ToString()
		{
			return info.ToString();
		}

		public void reset(ConnectionInfo info)
		{
			this.info = info;
			_shutdown.Value = false;
		}

		public ConsumerState this[ConsumerId id]
		{
			get
			{
				ConsumerState consumerState = null;

				consumers.TryGetValue(id, out consumerState);
				
#if DEBUG
				if(null == consumerState)
				{
					// Useful for dignosing missing consumer ids
					string consumerList = string.Empty;
					foreach(ConsumerId consumerId in consumers.Keys)
					{
						consumerList += consumerId.ToString() + "\n";
					}

					System.Diagnostics.Debug.Assert(false,
						string.Format("Consumer '{0}' did not exist in the consumers collection.\n\nConsumers:-\n{1}", id, consumerList));
				}
#endif
				return consumerState;
			}
		}

		public void addConsumer(ConsumerInfo info)
		{
			checkShutdown();

			ConsumerState consumerState = new ConsumerState(info);

			if(consumers.ContainsKey(info.ConsumerId))
			{
				consumers[info.ConsumerId] = consumerState;
			}
			else
			{
				consumers.Add(info.ConsumerId, consumerState);
			}
		}

		public ConsumerState removeConsumer(ConsumerId id)
		{
			ConsumerState ret = null;

			if(consumers.TryGetValue(id, out ret))
			{
				consumers.Remove(id);
			}
			return ret;
		}

		public ConnectionInfo Info
		{
			get
			{
				return info;
			}
		}

		public AtomicCollection<ConsumerId> ConsumerIds
		{
			get
			{
				return consumers.Keys;
			}
		}

		public AtomicCollection<ConsumerState> ConsumerStates
		{
			get
			{
				return consumers.Values;
			}
		}

		private void checkShutdown()
		{
			if(_shutdown.Value)
			{
				throw new ApplicationException("Disposed");
			}
		}

		public void shutdown()
		{
			if(_shutdown.CompareAndSet(false, true))
			{
                this.consumers.Clear();
			}
		}
	}
}