/// François-Régis Colin
/// http://www.tls.cena.fr/products/ivy/
/// *
/// (C) CENA
/// *
/// 
[assembly: System.CLSCompliant(true)]
namespace IvyBus
{
	using System;
	using System.IO;
	using System.Collections;
	using System.Collections.Specialized;
	using System.Collections.Generic;
	using System.Net;
	using System.Net.Sockets;
	using System.Threading;
	using System.Configuration;
	using System.Globalization;
	using System.Text.RegularExpressions;
	using System.Text;
	using System.Reflection;
	using System.Diagnostics;
	using System.Collections.ObjectModel;
	using IvyBus.Properties;

	/// <summary> The Main bus Class
	/// </summary>
	/// 
	public class Ivy    
	{
		/* Event */
		/// <summary>
		/// raise when an new IvyClient is connected
		/// </summary>
		public event EventHandler<IvyEventArgs> ClientConnected;
		/// <summary>
		/// raise when an new IvyClient is disconnected
		/// </summary>
		public event EventHandler<IvyEventArgs> ClientDisconnected;
		/// <summary>
		/// raise when a direct message is received
		/// </summary>
		public event EventHandler<IvyEventArgs> DirectMessageReceived;
		/// <summary>
		/// raise when some IvyClient  ask me to die
		/// </summary>
		public event EventHandler<IvyDieEventArgs> DieReceived;
		/// <summary>
		/// raise when an IvyClient register a binding
		/// </summary>
		public event EventHandler<IvyEventArgs> BindingAdd;
		/// <summary>
		/// raise when an IvyClient unregister a binding
		/// </summary>
		public event EventHandler<IvyEventArgs> BindingRemove;
		/// <summary>
		/// raise when an IvyClient  binding is filteredout
		/// </summary>
		public event EventHandler<IvyEventArgs> BindingFilter;
		/// <summary>
		/// raise when an IvyClient changer a binding
		/// </summary>
		public event EventHandler<IvyEventArgs> BindingChange;
		/// <summary>
		/// raise when an error message is received
		/// </summary>
		public event EventHandler<IvyEventArgs> ErrorMessage;

		/// <summary>
		/// Flag for displaying internal debug message of the protocol intrinsics
		/// </summary>
		public static bool DebugProtocol
		{
			get
			{
				return debugProtocol;
			}
			set
			{
				debugProtocol = value;
			}

		}
		/// <summary>
		/// Language for the Ivy SendMsg formating default en-US 
		/// ie: send point on float value sent
		/// </summary>
		public CultureInfo Culture
		{
			get
			{
				return culture;
			}
			set
			{
				culture = value;
			}

		}

		/// <summary>IvyClients accesses the list of the connected clients</summary>

		public ReadOnlyCollection<IvyClient> IvyClients
		{
			get
			{
				return new ReadOnlyCollection<IvyClient>(clients);
			}

		}
		
		/// <summary>AppName the application name</summary>

		public string AppName
		{
			set
			{
				appName = value;
			}
			get
			{
				return appName;
			}

		}
		/// <summary>
		/// AppId the Application Unique ID
		/// </summary>

		public string AppId
		{
			get
			{
				return applicationUniqueId;
			}

		}
		
		/// <summary>
		/// the Ivy Protocol version 
		/// </summary>
		public int ProtocolVersion
		{
			get
			{
				return protocolVersion;
			}

		}
		/// <summary>
        /// IsSynchronous is the bus Synchronous of the main thread ( ie callback running in the main thread) ?
		/// </summary>
		private bool synchronous = true;
		public bool Synchronous
		{
			set
			{
				synchronous = value && syncContext != null;
			}
			get
			{
				return synchronous;
			}

		}

		/// <summary>
		/// IsRunning is the bus Started and connected ?
		/// </summary>
		public bool IsRunning
		{
			get
			{
				return !stopped;
			}

		}
		///<summary>SentMessageClasses the first word token of sent messages
		///<remarks> optimise the parsing process when sending messages </remarks>
		///</summary>

		public Collection<string> SentMessageFilter
		{
			get
			{
				return sent_messageFilter;
			}
		}
		/// <summary>ReadyMessage message send when Application receive all the regexp at the connection of the client</summary>

		public string ReadyMessage
		{
			get { return ready_message; }
			set { ready_message = value; }
		}

		internal class MyTcpListener : TcpListener
		{
			public MyTcpListener(IPAddress address, int port)
				: base(address, port)
			{
			}
			public bool IsActive()
			{
				return this.Active;
			}
		}
		///  the name of the application on the bus
		internal string appName;
		/// the port for the UDP rendez vous, if none is supplied
		internal const ushort DefaultPort = 2010;
		/// the domain for the UDP rendez vous
		private static readonly string DefaultDomain = "127.0.0.1:" + DefaultPort;
		internal int protocolVersion = 3;
		private static bool debugProtocol;      // false by default runtime
		private static int serial = -1; /* an unique ID for each regexp */ // -1 to start numbering at 0
		private MyTcpListener app;
		private List<IvyWatcher> watchers;
		private Thread serverThread; // to ensure quick communication of the end
		private AutoResetEvent tcplistener_running;
		private bool ipv6;

		/// <summary>
		/// the Ivy IP version to use 
		/// </summary>
		public bool IpV6
		{
			get { return ipv6; }
		}

		/// <summary>
		/// the Ivy Assembly version
		/// </summary>
		static public Version Version
		{
			get { return Assembly.GetExecutingAssembly().GetName().Version; }
		}
		// Class representing Ivy Binding receive from client
		internal class IvyClientBinding
		{
			internal IvyBindingBase binding;
			internal Dictionary<IvyClient, List<int>> client_bindind_ids;
		}
		// The Application bindings
		internal Dictionary<int, IvyApplicationBinding> bindings;
		// the clients bindings
		private Dictionary<string, IvyClientBinding > client_bindings;
		private List<IvyClient> clients;
		private Collection<string> sent_messageFilter;
		private bool stopped = true;
		internal int applicationPort; /* Application port number */
		internal IPAddress applicationHost; /* Application host number */
		internal string applicationUniqueId;  /* identifier Application unique timestamp-ipaddress-port */
		private string ready_message;
		private CultureInfo culture = new CultureInfo("en-us");
		internal static Encoding ivyEncoding = Encoding.GetEncoding("iso-8859-15"); // ASCII 8 bits  iso-8859-2 
 
		// for synchronous event 
#if (PocketPC)
		private System.Windows.Forms.ContainerControl parentControl;
#else
		private readonly SynchronizationContext syncContext;
#endif


		/// <summary>
		/// Initializes a new instance of the Ivy Bus.
		/// Readies the structures for the software bus connexion.
		/// </summary>
		public Ivy()
		{
			this.ipv6 = false;
			clients = new List<IvyClient>();
			bindings = new Dictionary<int, IvyApplicationBinding>();
			client_bindings = new Dictionary<string, IvyClientBinding>();
			sent_messageFilter = new Collection<string>();
#if (!PocketPC)
			syncContext = SynchronizationContext.Current;
			debugProtocol = Properties.Settings.Default.IvyDebug;
			protocolVersion = Properties.Settings.Default.IvyProtocolVersion;
#endif
			// get binding from Attribute IvyBinding
			//TODO Autobinding attribute
#if (PocketPC)
			if (parentControl != null)
				BindAttibute(parentControl);
#endif
			Assembly assembly = Assembly.GetCallingAssembly();
			if ( assembly != this.GetType().Assembly )
				BindAttribute(assembly);
		}
		
		/// <summary>
		/// Readies the structures for the software bus connexion.
		/// </summary>
		/// <example> This sample shows how to start working with Ivy.
		/// <code>
		/// Ivy bus = new Ivy("Dummy agent","ready");
		/// bus.bindMsg("(.*)",myMessageListener);
		/// bus.start(null);
		/// </code>
		/// How to send & receive:
		/// the Ivy agent A performs <c>b.bindMsg("^Hello (*)",cb);</c>
		/// the Ivy agent B performs <c>b2.sendMsg("Hello world");</c>
		/// a thread in A will run the callback cb with its second argument set
		/// to a array of string, with one single element, "world"
		/// </example>
		/// <remarks>
		/// the real work begin in the start() method
		/// </remarks>
		/// <seealso cref=" Ivy.start"/>
		/// <param name='name'>The name of your Ivy agent on the software bus
		/// </param>
		/// <param name='message'>The hellow message you will send once ready
		/// </param>
		public Ivy(string name, string readyMessage)
			: this()
		{
			appName = name;
			this.ready_message = readyMessage;
			
			// get binding from Attribute IvyBinding
			//TODO Autobinding attribute
			Assembly assembly = Assembly.GetCallingAssembly();
			if (assembly != this.GetType().Assembly)
				BindAttribute(assembly);
		}
		

		internal void AddBinding(int id, IvyClient clnt, IvyBindingBase bindexp)
		{
			bool change = false;
			IvyClientBinding clientbind;
			lock (client_bindings)
			{
				if (client_bindings.ContainsKey(bindexp.Expression))
				{
					// check if id exits to remove it

					clientbind = client_bindings[bindexp.Expression];

					foreach (IvyClientBinding clbind in client_bindings.Values)
					{
						lock (clbind.client_bindind_ids)
						{
							if (clbind.client_bindind_ids.ContainsKey(clnt))
							{
								if (clbind.client_bindind_ids[clnt].Contains(id))
								{
									// remove from old
									clbind.client_bindind_ids[clnt].Remove(id);
									// add to new later
									change = true; //mark to call right handler
									break;
								}
							}
						}

					}

				}
				else
				{
					clientbind = new IvyClientBinding();
					clientbind.binding = bindexp;
					clientbind.client_bindind_ids = new Dictionary<IvyClient, List<int>>();
					clientbind.client_bindind_ids[clnt] = new List<int>();
					client_bindings[bindexp.Expression] = clientbind;

				}
			}
			
			lock (clientbind.client_bindind_ids)
			{
				if (!clientbind.client_bindind_ids.ContainsKey(clnt))
				{
					clientbind.client_bindind_ids[clnt] = new List<int>();
				}
				clientbind.client_bindind_ids[clnt].Add(id);
			}
			if (change)
			{
				OnClientChangeBinding(new IvyEventArgs(clnt, id, bindexp.Expression));
			}
			else
			{
				OnClientAddBinding(new IvyEventArgs(clnt, id, bindexp.Expression));
			}
		}
		internal void DelBinding(int id, IvyClient clnt)
		{
			IvyClientBinding clientbind = null;
			lock (client_bindings)
			{
				foreach (IvyClientBinding clbind in client_bindings.Values)
				{
					lock (clbind.client_bindind_ids)
					{
						if (clbind.client_bindind_ids.ContainsKey(clnt))
						{
							clbind.client_bindind_ids[clnt].Remove(id);
							clientbind = clbind;
							break;
						}
					}
				}
				if (clientbind != null)
				{
					lock (clientbind.client_bindind_ids)
					{
						if (clientbind.client_bindind_ids.Count == 0)
						{
							client_bindings.Remove(clientbind.binding.Expression);
						}
					}
				}
			}
			if (clientbind != null )
				OnClientRemoveBinding(new IvyEventArgs(clnt, id, clientbind.binding.Expression));
						
		}
		/// <summary>
		/// Automatic binding on static method of a Type 
		/// </summary>
		/// <param name="type"></param>
		public void BindAttribute(Type type)
		{
			if (type == null) return;
			//Get instance of the IvyBindingAttribute. 
			foreach (MethodInfo m in type.GetMethods(BindingFlags.Static | BindingFlags.NonPublic))
			{
				foreach (IvyBindingAttribute attr in Attribute.GetCustomAttributes(m, typeof(IvyBindingAttribute)))
				{
					//TODO check paramater type MessageHandler 
					Debug.WriteLine("IvyBinding '" + attr.GetFormattedExpression(null) + "' to Method " + m.Name);
					EventHandler<IvyMessageEventArgs> handler;
#if (PocketPC)
					//Createdelegate mydlg = new Createdelegate(m, null, EventArgs.Empty);
					//bindMsg(attr.GetExpression(null), mydlg);
					handler = null;
#else
					handler = (EventHandler<IvyMessageEventArgs>)Delegate.CreateDelegate(typeof(EventHandler<IvyMessageEventArgs>), m);
#endif
					BindMsg(attr.GetFormattedExpression(null), handler);
				}
			}
		}
		
		
		/// <summary>
		/// Autobinding on instance method
		/// </summary>
		/// <param name="target"></param>
		public void BindAttribute(object target)
		{
			if (target == null) return;
			Type type = target.GetType();
			//Get instance of the IvyBindingAttribute. 
			foreach (MethodInfo m in type.GetMethods(BindingFlags.Instance | BindingFlags.NonPublic))
			{
				foreach (IvyBindingAttribute attr in Attribute.GetCustomAttributes(m, typeof(IvyBindingAttribute)))
				{
					//TODO check paramater type MessageHandler 
					Ivy.traceProtocol(Resources.Ivy, "BindAttibute " + attr.GetFormattedExpression(target) + "' to Method " + m.Name);
					EventHandler<IvyMessageEventArgs> handler;
#if (PocketPC)
					handler = null; // TODO
#else
					handler = (EventHandler<IvyMessageEventArgs>)Delegate.CreateDelegate(typeof(EventHandler<IvyMessageEventArgs>), target, m);
#endif
					BindMsg(attr.GetFormattedExpression(target), handler);
				}
			}

		}
		// Autobinding on IvyBindingAttribute method
		/// <summary>
		/// Automatic binding of IvyBindAttribute in an assembly
		/// </summary>
		/// <param name="target"></param>
		public void BindAttribute(Assembly target)
		{
			if (target != null)
			{
				foreach (Type typ in target.GetTypes())
				{
					BindAttribute(typ);
				}
			}
		}
		/// <summary>
		/// connects the Ivy bus to a domain or list of domains.
		/// </summary>
		/// <param name="domainbus">a domain of the form 10.0.0:1234, it is similar to the
		/// netmask without the trailing .255. This will determine the meeting point
		/// of the different applications. Right now, this is done with an UDP
		/// broadcast. Beware of routing problems ! You can also use a comma
		/// separated list of domains.</param>
		/// <remarks>
		/// One thread (IvyWatcher) for each traffic rendezvous (either UDP broadcast or TCP Multicast).
		/// One thread (serverThread/Ivy) to accept incoming connexions on server socket.
		/// a thread for each IvyClient when the connexion has been done.
		/// </remarks>
		public void Start(string domainBus)
		{
			domainBus = GetDomain(domainBus);
			// check for IPV6 mode
			Domain[] d = parseDomains(domainBus);
			IPAddress group = IPAddress.Parse(d[0].Domainaddr);
			ipv6 = group.IsIPv6Multicast;

			try
			{
				long seed = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
				Random rand = new Random( (int)seed );

				app = new MyTcpListener(ipv6 ? IPAddress.IPv6Any :IPAddress.Any, 0);
				app.Start(); // should be started before getting port
				applicationHost = LocalIP;
				applicationPort = ((IPEndPoint)app.LocalEndpoint).Port;
				applicationUniqueId = string.Format(culture,"{0}:{1}:{2}",
					rand.Next(),
					seed,
					//applicationHost.ToString().Replace(".", ""),
					applicationPort);

			}
			catch (IOException e)
			{
				throw new IvyException("can't open TCP service socket " + e);
			}
			Ivy.traceProtocol("BindAttibute", "Ivy protocol: " + ProtocolVersion + " TCP service open on port " + applicationPort);
			watchers = new List<IvyWatcher>();

			// readies the rendezvous : an IvyWatcher (thread) per domain bus
			for (int index = 0; index < d.Length; index++)
			{
				IvyWatcher watcher = new IvyWatcher(this, d[index].Domainaddr, d[index].Port, ipv6 );
				watchers.Add(watcher);
			}
			serverThread = new Thread(new ThreadStart(this.TcpListener));
			serverThread.Name = "Ivy Tcp Server Thread";
			stopped = false;
			tcplistener_running = new AutoResetEvent(false);
			serverThread.Start();

			// Wait for readyness
			tcplistener_running.WaitOne();
 
			// sends the broadcasts and listen to incoming connexions
			for (int i = 0; i < watchers.Count; i++)
			{
				watchers[i].start();
			}
		}
		internal void SortClients()
		{
			lock (clients)
			{
				//clients.Sort(new IvyClient.IvyClientPriority());
				clients.Sort();
			}
		}
		

		internal static Domain[] parseDomains(string domainbus)
		{
			string[] st = domainbus.Split(',');
			Domain[] d = new Domain[st.Length];
			for (int i = 0; i < st.Length; i++)
			{
				d[i] = new Domain(st[i]);
			}
			return d;
		}

		/// <summary>
		/// disconnects from the Ivy bus
		/// </summary>
		public void Stop()
		{
			if (stopped)
				return;
			lock (app)
			{
				stopped = true;
				Ivy.traceProtocol(Resources.Ivy, "beginning stopping the bus");
				try
				{
					// stopping the serverThread
					if (serverThread != null)
					{
						app.Stop();
						// Wait for Thread to end.
						bool term = serverThread.Join(10000);
						if (!term && (serverThread != null)) serverThread.Abort();
						serverThread = null;
					}
					// The serverThread might be stopped even before having been created
					if (app != null)
						app.Stop();
					// stopping the IvyWatchers
					if (watchers != null)
						for (int i = 0; i < watchers.Count; i++)
						{
							((IvyWatcher)watchers[i]).stop();
						}
					// stopping the remaining IvyClients
					// copy the values in temporary variable to eliminate Thread modifying collection
					if (clients.Count != 0)
					{
						IvyClient[] copyClient;
						lock (clients)
						{
							copyClient = new IvyClient[clients.Count];
							clients.CopyTo(copyClient);
						}
						foreach (IvyClient client in copyClient)
						{
							client.close(true); // will notify the reading thread
							//removeClient(client); already donne in the thread
						}
					}
				}
				catch (IOException e)
				{
					Ivy.traceError(Resources.Ivy, "IOexception Stop " + e.Message);
				}
				Ivy.traceProtocol(Resources.Ivy, "the bus should have stopped so far");
			}
		}
		/// <summary> 
		/// join the main thread of Ivy ( ie wait until stopped )
		/// </summary>
		/// <remarks>
		/// Performs a join on the Principal Thread.
		/// </remarks>
		/// <param name='millisecondsTimeout'>Number of millisecondes to wait before the Thread Stop.</param>
		/// <returns>
		/// true if the thread stopped; false if it did not stop after the expiry of the period specified by the parameter millisecondsTimeout
		/// </returns>
		public bool Join(int millisecondsTimeout)
		{
			return serverThread.Join(millisecondsTimeout);
		}
		/// <summary> 
		/// Block the calling Thread until Ivy Stop
		/// </summary>
		/// <remarks>
		/// Performs a join on the Principal Thread.
		/// </remarks>
		public void MainLoop()
		{
			this.Join(Timeout.Infinite);
		}

		/// <summary> 
		/// Send a formated message to someone on the bus
		/// </summary>
		/// <remarks>
		/// Performs a pattern matching according to everyone's regexps, and sends
		/// the results to the relevant ivy agents.
		/// There is one thread for each client connected, we could also
		/// create another thread each time we send a message.
		/// </remarks>
		/// <param name='format'>A string message format to build  the message</param>
		/// <param name='args'>args used in message format</param>
		/// <returns>
		/// the number of messages actually sent
		/// </returns>
		public int SendMsg(string format, params object[] args)
		{
			// send to everybody
			string msg = string.Format(culture, format, args);
			int count = 0;
			// hash message in V4 protocol only
			if (ProtocolVersion == 4)
				IvyBindingSimple.Prepare(msg);
			// an alternate implementation would one sender thread per client
			// instead of one for all the clients. It might be a performance issue
			// Tentative of using BeginInvoke EndInvoke is slower 
			lock (client_bindings)
			{
				foreach (IvyClientBinding clbind in client_bindings.Values)
				{
					string[] matches = clbind.binding.Match(msg);
					if (matches != null)
					{
						lock (clbind.client_bindind_ids)
						{

							foreach (KeyValuePair<IvyClient, List<int>> assoc in clbind.client_bindind_ids)
							{
								foreach (ushort id in assoc.Value)
								{
									count += assoc.Key.sendMsg(id, matches);
								}

							}

						}
					}
					
				}
				
			}

			return count;
		}

		internal int SendMsgToClient(IvyClient clnt, string format, params object[] args)
		{
			string msg = string.Format(culture, format, args);
			int count = 0;
			// hash message in V4 protocol only
			if (ProtocolVersion == 4)
				IvyBindingSimple.Prepare(msg);
			// an alternate implementation would one sender thread per client
			// instead of one for all the clients. It might be a performance issue
			lock (client_bindings)
			{

				foreach (IvyClientBinding clbind in client_bindings.Values)
				{
					string[] matches = clbind.binding.Match(msg);
					if (matches != null)
					{
						lock (clbind.client_bindind_ids)
						{
								if (clbind.client_bindind_ids.ContainsKey(clnt))
								{
									List<int> ids = clbind.client_bindind_ids[clnt];
									foreach (ushort id in ids)
									{
										count += clnt.sendMsg(id, matches);
									}
								}   
						}
					}
				}
			}
				
			
			return count;
		}
		/// <summary>
		/// Make a binding to a message using regular expresssion
		/// </summary>
		/// <param name="newBinding"></param>
		/// <returns></returns>
		public int BindMsg(IvyApplicationBinding newBinding)
		{     
			newBinding.Key = Interlocked.Increment(ref serial);
			
			lock (bindings) bindings.Add(newBinding.Key, newBinding);
			// notifies the other clients this new regexp
			lock (clients)
			{
				foreach (IvyClient c in clients)
				{
					c.stream.TokenAddBinding(newBinding.Binding, newBinding.Key, newBinding.FormattedExpression);
				}
			}
			return newBinding.Key;
		}
		/// <summary>
		/// Subscribes to a regular expression.
		/// </summary>
		/// <param name="regexp">a regular expression, groups are done with parenthesis</param>
		/// <param name="callback">any objects implementing the EventHandler<IvyMessageEventArgs> </param>
		/// <param name="args">The args.</param>
		/// <returns>the id of the regular expression</returns>
		/// <remarks>
		/// The callback will be executed with
		/// the saved parameters of the regexp as arguments when a message will sent
		/// by another agent. A program doesn't receive its own messages.
		/// the expression cant containt some dynamics argument replacement of the form  %number[:objectFormat]% 
		/// the string will be replaced by  arg[number].ToString(objectFormat)
		/// </remarks>
		//
		public int BindMsg(string expression, EventHandler<IvyMessageEventArgs> callback, params object[] args)
		{
			// creates a new binding (regexp,callback)
			IvyApplicationBinding newbind;
			newbind = new IvyApplicationBinding(BindingType.RegularExpression, expression, args);
			newbind.Callback += callback;
			return BindMsg(newbind);
		}

		/// <summary>
		/// unsubscribes a regular expression
		/// </summary>
		/// <param name="id">the id of the regular expression, returned when it was bound</param>
		public void UnbindMsg(int id)
		{
			if (!bindings.ContainsKey(id))
			{
				throw new IvyException("client wants to remove an unexistant regexp " + id);
			}
			lock (clients)
			{
				foreach (IvyClient c in clients)
				{
					try
					{
						if ( c.stream != null )
							c.stream.TokenDelBinding(id);
					}
					catch (IOException)
					{
						// client closed ignore it
					}
				}
			}
			lock (bindings) bindings.Remove(id);
		}
		/// <summary>
		/// Change a binding already registred
		/// </summary>
		/// <param name="id"></param>
		/// <param name="expression"></param>
		/// <returns></returns>
		public int ChangeMsg(int id, string expression)
		{
			IvyApplicationBinding newbind;
			if (!bindings.ContainsKey(id))
			{
				throw new IvyException("client wants to change an unexistant regexp " + id);
			}
			
			// change binding (regexp,callback)
			lock (bindings)
			{
				newbind = bindings[id];
				newbind.Expression = expression;
			}
			// notifies the other clients this new regexp
			lock (clients)
			{
				foreach (IvyClient c in clients)
				{
					c.stream.TokenAddBinding(newbind.Binding, newbind.Key, newbind.FormattedExpression);
				}
			}
			return id;
		}


		/// <summary>
		/// unsubscribes a regular expression
		/// </summary>
		/// <param name="re">the string for the regular expression</param>
		/// <returns>
		/// a boolean, true if the regexp existed, false otherwise or
		/// whenever an exception occured during unbinding
		/// </returns>
		public bool UnbindMsg(string re)
		{
			foreach (IvyApplicationBinding bind in bindings.Values)
			{
				if (bind.Expression == re)
				{
					try
					{
						UnbindMsg(bind.Key);
					}
					catch (IvyException)
					{
						return false;
					}
					return true;
				}
			}
			return false;
		}


		/// <summary>
		/// Subscribes to a simple expression ( msg ar1 arg2 arg3 etc).
		/// </summary>
		/// <remarks>
		/// The callback will be executed with
		/// the saved parameters of the regexp as arguments when a message will sent
		/// by another agent. A program doesn't receive its own messages.
		/// </remarks>
		/// 
		/// <param name='regexp'>a regular expression, groups are done with parenthesis</param>
		/// <param name='callback'>any objects implementing the EventHandler<IvyMessageEventArgs></param>
		/// <returns>
		/// the id of the regular expression
		/// </returns>
		public int BindSimpleMsg(string expression, EventHandler<IvyMessageEventArgs> callback, params object[] args)
		{
			// creates a new binding (regexp,callback)
			IvyApplicationBinding newbind;
			newbind = new IvyApplicationBinding(BindingType.Simple, expression, args);
			newbind.Callback += callback;
			return BindMsg(newbind);
		}
		/// <summary>
		/// Dies the specified target.
		/// </summary>
		/// <param name="target">The target.</param>
		/// <param name="message">The reason message.</param>
		/// <returns></returns>
		public int Die(string target, string message)
		{
			ReadOnlyCollection<IvyClient> v = GetClientsByName(target);
			foreach (IvyClient clnt in v)
				clnt.stream.TokenDie(0, message);
			return v.Count;
		}
		/// <summary>
		/// Pings the specified target.
		/// </summary>
		/// <param name="target">The target.</param>
		/// <param name="message">The message.</param>
		/// <returns></returns>
		public int Ping(string target, string message)
		{
			int id = (int)DateTime.Now.Ticks;
			ReadOnlyCollection<IvyClient> v = GetClientsByName(target);
			foreach (IvyClient clnt in v)
			{
				clnt.stream.TokenPing(id, message);
			}
			return v.Count;
		}


		internal virtual void FireEvent(EventHandler<IvyEventArgs> ev, IvyEventArgs e)
		{
			if (ev != null)
			{
#if (PocketPC) 
				if (parentControl != null)
				{
					parentControl.Invoke(ev, this, e);
				}
#else
				if (synchronous)
				{
					SendOrPostCallback update = delegate(object state)
								  {
									  IvyEventArgs args = (IvyEventArgs)state;
									  ev(this, args);
								  };
					syncContext.Post(update, e);
				}
#endif
				else
					ev(this, e);
			}
		}


		internal virtual void OnDirectMessage(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = DirectMessageReceived;
			FireEvent(temp,e);
		}
		internal virtual void OnClientConnected(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = ClientConnected;
			FireEvent(temp,e);
		}
		internal virtual void OnClientDisconnected(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = ClientDisconnected;
			try
			{
				FireEvent(temp,e);
			}
#if (!PocketPC)
			catch (SynchronizationLockException)
			{
						// protect terminaison 
			}
#endif
			catch (ObjectDisposedException)
			{
				// protect terminaison 
			}
			
		}
		internal virtual void OnClientAddBinding(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = BindingAdd;
			FireEvent(temp,e);
		}
		internal virtual void OnClientRemoveBinding(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = BindingRemove;
			FireEvent(temp,e);
		}
		internal virtual void OnClientChangeBinding(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = BindingChange;
			FireEvent(temp, e);
		}
		internal virtual void OnClientFilterBinding(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = BindingFilter;
			FireEvent(temp,e);
		}
		internal virtual void OnError(IvyEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyEventArgs> temp = ErrorMessage;
			FireEvent(temp, e);
		}
#if (PocketPC)
		internal virtual void OnDie(IvyDieEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyDieEventArgs> temp = DieReceived;
			if (temp != null)
			{
				if (parentControl != null)
				{
					parentControl.Invoke(temp, this, e);
				}
				else
					temp(this, e);
			}
		}

#else
		internal virtual void OnDie(IvyDieEventArgs e)
		{
			// Copy to a temporary variable to be thread-safe.
			EventHandler<IvyDieEventArgs> temp = DieReceived;
			if (temp != null)
			{
				if (syncContext != null)
				{
					SendOrPostCallback update = delegate(object state)
								  {
									  IvyDieEventArgs args = (IvyDieEventArgs)state;
									  temp(this, args);
								  };
					syncContext.Post(update, e);
				}
				else
					temp(this, e);
			}
		}
#endif
		internal void OnMessage(IvyMessageEventArgs e)
		{
			if (!bindings.ContainsKey( e.Id))
			{
				throw new IvyException("(callCallback) Not regexp matching id " + e.Id);
			}
			IvyApplicationBinding bind = bindings[e.Id];

#if(PocketPC)
			bind.Firevent(parentControl, e);
#else
			bind.Firevent(syncContext,synchronous, e);
#endif
		}
	 
		/*
		* removes a client from the list
		*/
		internal void removeClient(IvyClient c)
		{
			lock (clients)
			{
				clients.Remove(c);
			}
			List<string> purge_bind = new List<string>();
			lock (client_bindings)
			{
				foreach (IvyClientBinding clbind in client_bindings.Values)
				{
					lock (clbind.client_bindind_ids)
					{
						clbind.client_bindind_ids.Remove(c);
						if ( clbind.client_bindind_ids.Count == 0 )
							purge_bind.Add( clbind.binding.Expression);
					}
				}
				// remove Binding if no client
				foreach ( string expr in purge_bind )
				{
					client_bindings.Remove(expr);
				}
			}
		}


		/// <summary>
		/// gives a list of IvyClient(s) with the name given in parameter
		/// </summary>
		/// <param name="name">The name of the Ivy agent you're looking for</param>
		/// <returns></returns>
		public ReadOnlyCollection<IvyClient> GetClientsByName(string name)
		{
			List<IvyClient> v = new List<IvyClient>();
			foreach (IvyClient ic in clients)
			{
				if (ic.ApplicationName.CompareTo(name) == 0)
					v.Add(ic);
			}
			return new ReadOnlyCollection<IvyClient>(v);
		}

		/////////////////////////////////////////////////////////////////:
		//
		// Protected methods
		//
		/////////////////////////////////////////////////////////////////:

		internal void addClient(IvyClient client)
		{
			if (stopped)
				return;
			
			lock (clients)
			{
				clients.Add(client);
			}
			
		}

		/// <summary>
		/// return the first non loopback adress
		/// on a one network interface machine it will be my IP adresse
		/// </summary>
		public static IPAddress LocalIP
		{
			get
			{
				IPAddress returnaddr = null;
				//TODO remove ALL reverse DNS search !!!!
				IPHostEntry ip = Dns.GetHostEntry(Dns.GetHostName());
				foreach (IPAddress addr in ip.AddressList)
				{
					returnaddr = addr;
					if (IPAddress.IsLoopback(addr)) continue;
					break;
				}
				return returnaddr;
			}
		}
		/// <summary>
		/// Get the FDQN Domain from a string
		/// </summary>
		/// <param name="domainBus"></param>
		/// <returns></returns>
		public static string GetDomain(string domainBus)
		{
#if (PocketPC) // TODO integrate in normal version
			if (domainbus == null || domainbus.Length == 0)
			{
				IPAddress addr = GetLocalIP();
				//TODO Find Braodcast addr from IP;
				byte[] bytes = addr.GetAddressBytes();
				if (IPAddress.IsLoopback(addr))
				{
					// 127.255.255.255
					bytes[1] = 255;
					bytes[2] = 255;
					bytes[3] = 255;
				}
				else
				{ 
					// else assume class C network
					// TODO find exact netmask
					bytes[3] = 255;
				}
				IPAddress bcast = new IPAddress(bytes);
				domainbus = bcast + ":" + Domain.getPort(domainbus);
			}
#else
			if (domainBus == null || domainBus.Length == 0 )
			{
				domainBus = Environment.GetEnvironmentVariable("IVYBUS");
			}

			if (domainBus == null || domainBus.Length == 0)
			{
				domainBus = Properties.Settings.Default.IvyBus;
			} 
#endif
			if (domainBus == null || domainBus.Length == 0)
				domainBus = DefaultDomain;
			return domainBus;
		}


		/// checks the "validity" of a regular expression. //TODO put in IvyBinding
		internal bool CheckRegexp(string exp)
		{
			bool regexp_ok = true;
			// Attention Bug 
			// ClockStop ClockStart & ^Clock(Start|Pause)
			// should Stop to the first parent
			if ((sent_messageFilter.Count != 0) && exp.StartsWith("^"))
			{
				regexp_ok = false;
				// extract first word from regexp...
				string token = Regex.Replace(exp, @"^\^(?<token>[a-zA-Z_0-9-]+).*", @"${token}");

				foreach (string exp_class in sent_messageFilter)
				{
					if (exp_class.StartsWith(token))
						return true;
				}
			}
			return regexp_ok;
		}

		/*
		* prevents two clients from connecting to each other at the same time
		* there might still be a lingering bug here, that we could avoid with the
		* SchizoToken.
		*/
		internal IvyClient checkConnected(IvyClient clnt)
		{
			IvyClient sameClnt = null;
			if (clnt.AppPort == 0)
			{
				Console.WriteLine(" client {0} port == 0 ", clnt.appName);
				return sameClnt;
			}
			lock (clients)
			{
				foreach (IvyClient client in clients)
				{
					if (clnt == client) continue; // SKIP himself
					if (client.sameIvyClient(clnt))
					{
						sameClnt = client;
						break;
					}
				}
			}
			return sameClnt;
		}

		/*
		* the service socket thread reader main loop
		*/
		private void TcpListener()
		{
			Ivy.traceProtocol(Resources.Ivy, "Ivy service Thread started");
			bool running = true;
			tcplistener_running.Set();
			while (running)
			{
				try
				{
					Socket socket = app.AcceptSocket();
					// early disconnexion
					if (stopped)
						break;
					// the peer called me
					IvyClient client = new IvyClient(this, socket, "Unkown(waiting for name reception)",0);
					client.SendBindings(); //TODO in a Thread or wait for the peer to sent his before sending mine 
		   
				}
				catch (IOException e)
				{
					Ivy.traceError(Resources.Ivy,Resources.IvyIOException + e.Message);
				}
				catch (SocketException e)
				{
					Ivy.traceError(Resources.Ivy,Resources.IvySocketException + e.Message);
					running = false;
				}
			}
			Ivy.traceProtocol(Resources.Ivy, "Ivy service Thread stopped");
		}

		[Conditional("DEBUG")]
		internal static void traceProtocol(string name, string message)
		{
			if ( debugProtocol )
				Console.WriteLine( "-->{0}<-- {1}", name, message);
		}
		internal static void traceError(string name, string message)
		{
			Console.WriteLine("-->{0}<-- {1}", name, message);
		}

		internal class Domain
		{
			public virtual string Domainaddr
			{
				get
				{
					return domainaddr;
				}

			}
			public virtual int Port
			{
				get
				{
					return port;
				}

			}
			private string domainaddr;
			private int port;
			public Domain(string net):this( getDomain(net),getPort(net)) 
			{
			}
			public Domain(string domainaddr, int port)
			{
				this.domainaddr = domainaddr;
				this.port = port;
			}
			public override string ToString()
			{
				return domainaddr + ":" + port;
			}
			public static string getDomain(string net)
			{
				int sep_index = net.LastIndexOf(":");
				if (sep_index != -1)
				{
					net = net.Substring(0, (sep_index) - (0));
				}
				try
				{
					if (!net.Contains("::")) // if not IPV6 multicast paste with 255
					{
						net += ".255.255.255";
						Regex exp = new Regex("^(\\d+\\.\\d+\\.\\d+\\.\\d+).*");
						net = exp.Replace(net, "$1");
					}
				}
				catch (ArgumentException e)
				{
					Ivy.traceError(Resources.Ivy,Resources.BadBroadcast + net + "error " + e.Message);
					return null;
				}
				return net;
			}

			public static int getPort(string net)
			{
				if (net == null) { return Ivy.DefaultPort; }
				int sep_index = net.LastIndexOf(":");
				int port = (sep_index == -1) ? Ivy.DefaultPort : Int32.Parse(net.Substring(sep_index + 1));
				return port;
			}
		}

		/// <summary>
		/// check Validity of Ivy Bus Domain
		/// </summary>
		/// <param name="domain"></param>
		/// <returns></returns>
        public static bool ValidatingDomain(string domain)
        {
            IPAddress result;
            bool valid = false;
            string addr = Domain.getDomain(domain);
            try
            {
                int port = Domain.getPort(domain);
                if (port < IPEndPoint.MinPort || port > IPEndPoint.MaxPort) return false;
            }
            catch (OverflowException e)
            {
                return false;
            }
            if (String.IsNullOrEmpty(addr))
            {
                // address wasnt provided so return false
                valid = false;
            }
            else
            {
                //use TryParse to see if this is a 
                //valid ip address. TryParse returns a
                //boolean based on the validity of the
                //provided address, so assign that value
                //to our boolean variable
                valid = IPAddress.TryParse(addr, out result);
            }
            return valid;
        }

	}
}