//
// HttpChannelListener.cs
//
// Author:
//	Atsushi Enomoto <atsushi@ximian.com>
//
// Copyright (C) 2010 Novell, Inc.  http://www.novell.com
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Net;
using System.Net.Security;
using System.ServiceModel;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;
using System.ServiceModel.Security;
using System.Text;
using System.Threading;

namespace System.ServiceModel.Channels.Http
{
	internal class HttpChannelListener<TChannel> : InternalChannelListenerBase<TChannel>, IChannelDispatcherBoundListener
		where TChannel : class, IChannel
	{
		HttpListenerManager listener_manager;

		public HttpChannelListener (HttpTransportBindingElement source, BindingContext context)
			: base (context)
		{
			if (ServiceHostBase.CurrentServiceHostHack != null)
				DispatcherBuilder.ChannelDispatcherSetter = delegate (ChannelDispatcher cd) { this.ChannelDispatcher = cd; };

			this.Source = source;
			// The null Uri check looks weird, but it seems the listener can be built without it.
			// See HttpTransportBindingElementTest.BuildChannelListenerWithoutListenUri().
			if (Uri != null && source.Scheme != Uri.Scheme)
				throw new ArgumentException (String.Format ("Requested listen uri scheme must be {0}, but was {1}.", source.Scheme, Uri.Scheme));

			foreach (BindingElement be in context.Binding.Elements) {
				MessageEncodingBindingElement mbe = be as MessageEncodingBindingElement;
				if (mbe != null) {
					MessageEncoder = CreateEncoder<TChannel> (mbe);
					break;
				}
			}
			if (MessageEncoder == null)
				MessageEncoder = new TextMessageEncoder (MessageVersion.Default, Encoding.UTF8);

			if (context.BindingParameters.Contains (typeof (ServiceCredentials)))
				SecurityTokenManager = new ServiceCredentialsSecurityTokenManager ((ServiceCredentials) context.BindingParameters [typeof (ServiceCredentials)]);
		}

		public ChannelDispatcher ChannelDispatcher { get; set; }

		public HttpTransportBindingElement Source { get; private set; }

		public HttpListenerManager ListenerManager {
			get {  return listener_manager; }
		}

		public ServiceCredentialsSecurityTokenManager SecurityTokenManager { get; private set; }

		ManualResetEvent accept_channel_handle = new ManualResetEvent (true);

		protected override TChannel OnAcceptChannel (TimeSpan timeout)
		{
			// HTTP channel could be accepted while there is no incoming request yet. The reply channel waits for the actual request.
			// HTTP channel listeners do not accept more than one channel at a time.
			DateTime start = DateTime.Now;
			accept_channel_handle.WaitOne (timeout - (DateTime.Now - start));
			accept_channel_handle.Reset ();
			TChannel ch = CreateChannel (timeout - (DateTime.Now - start));
			ch.Closed += delegate {
				accept_channel_handle.Set ();
			};
			return ch;
		}

		protected TChannel CreateChannel (TimeSpan timeout)
		{
			lock (ThisLock) {
				return CreateChannelCore (timeout);
			}
		}

		TChannel CreateChannelCore (TimeSpan timeout)
		{
			if (typeof (TChannel) == typeof (IReplyChannel))
				return (TChannel) (object) new HttpReplyChannel ((HttpChannelListener<IReplyChannel>) (object) this);

			throw new NotSupportedException (String.Format ("Channel type {0} is not supported", typeof (TChannel)));
		}

		protected override bool OnWaitForChannel (TimeSpan timeout)
		{
			throw new NotImplementedException ();
		}

		protected HttpListenerManager GetOrCreateListenerManager ()
		{
			var table = HttpListenerManagerTable.GetOrCreate (ChannelDispatcher != null ? ChannelDispatcher.Host : null);
			return table.GetOrCreateManager (Uri, Source);
		}

		protected override void OnOpen (TimeSpan timeout)
		{
			listener_manager = GetOrCreateListenerManager ();
			Properties.Add (listener_manager);
			listener_manager.RegisterListener (ChannelDispatcher, Source, timeout);
		}

		protected override void OnAbort ()
		{
			listener_manager.UnregisterListener (ChannelDispatcher, TimeSpan.Zero);
		}

		protected override void OnClose (TimeSpan timeout)
		{
			if (State == CommunicationState.Closed)
				return;
			base.OnClose (timeout);
			// The channels are kept open when the creator channel listener is closed.
			// http://blogs.msdn.com/drnick/archive/2006/03/22/557642.aspx
			listener_manager.UnregisterListener (ChannelDispatcher, timeout);
		}

		// immediately stop accepting channel.
		public override bool CancelAsync (TimeSpan timeout)
		{
			try {
				CurrentAsyncResult.AsyncWaitHandle.WaitOne (TimeSpan.Zero);
			} catch (TimeoutException) {
			}
			return true;
		}
	}
}