/*********************************************************************/
/*                                                                   */
/*                     AgentService Framework                        */
/*                       www.agentservice.it                         */
/*                                                                   */
/* Copyright (C) 2007 l.i.d.o. - DIST, University of Genoa, Italy    */
/* GNU Lesser General Public License                                 */
/*                                                                   */
/* This library is free software; you can redistribute it and/or     */
/* modify it under the terms of the GNU Lesser General Public        */
/* License as published by the Free Software Foundation,             */
/* version 2.1 of the License.                                       */
/*                                                                   */
/* This library is distributed in the hope that it will be useful,   */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of    */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU */
/* Lesser General Public License for more details.                   */
/*                                                                   */
/* You should have received a copy of the GNU Lesser General Public  */
/* License along with this library; if not, write to the             */
/* Free Software Foundation, Inc., 59 Temple Place - Suite 330,      */
/* Boston, MA  02111-1307, USA.                                      */
/*                                                                   */
/*********************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using System.Collections;
using AgentService.Platform.AMS;
using AgentService.Platform.Modules;
using AgentService.Platform.Modules.Default;

namespace AgentService.Agent.Runtime
{
    /// <summary>
    /// RemoteDispatcher service: allows remote platforms and agents to receive events
    /// </summary>
    [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, AddressFilterMode = AddressFilterMode.Any)]
    class RemoteEventsDispatcher : IRemoteEventsDispatcher
    {
        private RemoteMsgClient msgClient;
        private IImprovedMessagingModule msgmod;

        /// <summary>
        /// An hashtable containing the last timestamp a platform requested its events
        /// </summary>
        private Hashtable timings = new Hashtable();

        public Hashtable Timings
        {
            get
            {
                return this.timings;
            }
        }

        /// <summary>
        /// An hashtable containing all the agents events for a given remote platform
        /// </summary>
        private Hashtable Events = new Hashtable();

        /// <summary>
        /// An hashtable containing the remote platform that ownes a given agent
        /// </summary>
        private Hashtable Identifiers = new Hashtable();

        public RemoteEventsDispatcher(RemoteMsgClient msgClient, IImprovedMessagingModule msg)
        {
            this.msgClient = msgClient;
            this.msgmod = msg;
            msgClient.OnIncomingConversation += new AgentService.Platform.MTS.ConversationDelegate(msgClient_OnIncomingConversation);
            //msgClient.OnMessageArrive += new MessageArrivedDelegate(msgClient_OnMessageArrive);
        }

        void OnMessageArrive(object sender, IncomingMessageEventArgs args)
        {
            this.AddEvent(args.aid, new RemoteEvent(args.aid, AgentService.Platform.PlatformEvent.MessageReceived, null, "SimpleMessage"));
        }

        void OnConversationMessageArrive(object sender, IncomingConversationMessageEventArgs args)
        {
            this.AddEvent(args.aid, new RemoteEvent(args.aid, AgentService.Platform.PlatformEvent.MessageReceived, null, args.ConversationId));
        }

        /// <summary>
        /// The delegate that handles an OnIncomingConversation event
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="args"></param>
        void msgClient_OnIncomingConversation(object sender, AgentService.Platform.MTS.ConversationArgs args)
        {
            RemoteConversation rmc = (RemoteConversation) args.Conversation;
            RemoteConversationDescriptor desc = new RemoteConversationDescriptor(rmc.Peer,rmc.ConvId,rmc.State);
            this.AddEvent(rmc.Owner, new RemoteEvent(rmc.Owner, AgentService.Platform.PlatformEvent.ConversationRequested,null,desc));
        }

        /// <summary>
        /// Registers a new remote platform
        /// </summary>
        /// <param name="platID">the platform guid</param>
        /// <returns></returns>
        public bool AddPlatform(string platID)
        {
            bool bOk;

            lock (this.Events)
            {
                if (Events.Contains(platID))
                {
                    bOk = false;
                }
                else
                {
                    Events.Add(platID, new List<RemoteEvent>());
                    lock (this.timings)
                    {
                        timings.Add(platID, System.DateTime.Now);
                    }
                    bOk = true;
                }
            }

            return bOk;
        }

        /// <summary>
        /// Deregisters a previously registered remote platform
        /// </summary>
        /// <param name="platID">the platform guid</param>
        /// <returns></returns>
        public bool RemovePlatform(string platID)
        {
            bool bOk;

            lock (this.Events)
            {
                if (Events.Contains(platID))
                {
                    lock (this.timings)
                    {
                        timings.Remove(platID);
                    }

                    Events.Remove(platID);
                    bOk = true;
                }
                else
                {
                    bOk = false;
                }
            }

            return bOk;
        }

        /// <summary>
        /// Gets all the event for the agents of a given remote platform
        /// </summary>
        /// <param name="platID">the platform guid</param>
        /// <returns></returns>
        public List<RemoteEvent> GetAllEvents(string platID)
        {
            List<RemoteEvent> list = new List<RemoteEvent>();

            lock (this.Events)
            {
                if (Events.Contains(platID))
                {
                    foreach (RemoteEvent ev in ((List<RemoteEvent>)Events[platID]))
                    {
                        list.Add(ev);
                    }
                    ((List<RemoteEvent>)Events[platID]).Clear();

                    lock (this.timings)
                    {
                        this.timings[platID] = System.DateTime.Now;
                    }
                }
            }

            return list;
        }

        /// <summary>
        /// Registers a new remote agent
        /// </summary>
        /// <param name="aid">the aid of the agent</param>
        /// <param name="platID">the id of the remote platform</param>
        /// <returns></returns>
        public bool RegisterAgent(AID aid, string platID)
        {
            bool bOk;

            lock (this.Events)
            {
                if (!Events.Contains(platID)) 
                {
                    Events.Add(platID, new List<RemoteEvent>());
                }
            }

            lock (this.Identifiers)
            {
                if (Identifiers.Contains(aid))
                {
                    bOk = false;
                }

                else
                {
                    Identifiers.Add(aid, platID);
                    this.msgmod.RegisterToIncomingMessage(this.OnMessageArrive,aid);
                    this.msgmod.RegisterToIncomingConversationMessage(this.OnConversationMessageArrive, aid);
                    bOk = true;
                }
            }
            
            return bOk;
        }

        /// <summary>
        /// Deregisters a previously registered remote agent
        /// </summary>
        /// <param name="aid">the aid of the agent</param>
        /// <param name="platID">the remote platform guid</param>
        /// <returns></returns>
        public bool DeRegisterAgent(AID aid, string platID)
        {
            bool bOk;

            lock (this.Identifiers)
            {
                if (Identifiers.Contains(aid))
                {
                    Identifiers.Remove(aid);
                    this.msgmod.DeregisterToIncomingMessage(this.OnMessageArrive, aid);
                    this.msgmod.DeregisterToIncomingConversationMessage(this.OnConversationMessageArrive, aid);
                    bOk = true;
                }

                else
                {
                    bOk = false;
                }
            }

            return bOk;
        }

        /// <summary>
        /// Adds a new remote event to be dispatched
        /// </summary>
        /// <param name="to">the agent aid of the recipient agent</param>
        /// <param name="ev">the remote event to be dispatched</param>
        /// <returns></returns>
        public bool AddEvent(AID to, RemoteEvent ev)
        {
            bool bOk;
            string platID;

            lock (this.Identifiers)
            {
                if (Identifiers.Contains(to))
                {
                    platID = (string)Identifiers[to];
                }
                else
                {
                    platID = null;
                }
            }

            if (platID != null)
            {
                lock (this.Events)
                {
                    ((List<RemoteEvent>)this.Events[platID]).Add(ev);
                    bOk = true;
                }
            }

            else
            {
                bOk = false;
            }

            return bOk;
        }

    }
}