/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSim Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using System.Net;
using System.Threading;
using OpenMetaverse;
using log4net;
using Nini.Config;
using Nwc.XmlRpc;
using OpenSim.Framework;
using OpenSim.Framework.Client;
using OpenSim.Region.Interfaces;
using OpenSim.Region.Environment.Interfaces;
using OpenSim.Region.Environment.Scenes;

namespace OpenSim.Region.Environment.Modules.Avatar.InstantMessage
{
    public class InstantMessageModule : IRegionModule
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        private readonly List<Scene> m_scenes = new List<Scene>();

        #region IRegionModule Members

        private bool gridmode = false;

        private IMessageTransferModule m_TransferModule = null;

        public void Initialise(Scene scene, IConfigSource config)
        {
            if (config.Configs["Messaging"] != null)
            {
                if (config.Configs["Messaging"].GetString(
                        "InstantMessageModule", "InstantMessageModule") !=
                        "InstantMessageModule")
                    return;
            }

            lock (m_scenes)
            {
                if (!m_scenes.Contains(scene))
                {
                    m_scenes.Add(scene);
                    scene.EventManager.OnClientConnect += OnClientConnect;
                    scene.EventManager.OnIncomingInstantMessage += OnGridInstantMessage;
                }
            }
        }

        void OnClientConnect(IClientCore client)
        {
            IClientIM clientIM;
            if (client.TryGet(out clientIM))
            {
                clientIM.OnInstantMessage += OnInstantMessage;
            }
        }

        public void PostInitialise()
        {
            m_TransferModule =
                m_scenes[0].RequestModuleInterface<IMessageTransferModule>();

            if (m_TransferModule == null)
                m_log.Error("[INSTANT MESSAGE]: No message transfer module, "+
                "IM will not work!");
        }

        public void Close()
        {
        }

        public string Name
        {
            get { return "InstantMessageModule"; }
        }

        public bool IsSharedModule
        {
            get { return true; }
        }

        #endregion

        private void OnInstantMessage(IClientAPI client, UUID fromAgentID,
                UUID fromAgentSession, UUID toAgentID,
                UUID imSessionID, uint timestamp, string fromAgentName,
                string message, byte dialog, bool fromGroup, byte offline,
                uint ParentEstateID, Vector3 Position, UUID RegionID,
                byte[] binaryBucket)
        {
            // This module handles exclusively private text IM from user
            // to user. All others will be caught in other modules
            //
            if (   dialog != (byte)InstantMessageDialog.MessageFromAgent
                && dialog != (byte)InstantMessageDialog.StartTyping
                && dialog != (byte)InstantMessageDialog.StopTyping)
            {
                return;
            }

            GridInstantMessage im = new GridInstantMessage(client.Scene,
                    fromAgentID, fromAgentName, fromAgentSession, toAgentID,
                    dialog, fromGroup, message, imSessionID,
                    offline != 0 ? true : false, Position,
                    binaryBucket);
            
            ProcessInstantMessage(client, im);
        }

        private void ProcessInstantMessage(IClientAPI client, GridInstantMessage im)
        {
            byte dialog = im.dialog;

            if (   dialog != (byte)InstantMessageDialog.MessageFromAgent
                && dialog != (byte)InstantMessageDialog.StartTyping
                && dialog != (byte)InstantMessageDialog.StopTyping)
            {
                return;
            }

            if (m_TransferModule != null)
            {
                m_TransferModule.SendInstantMessage(im,
                    delegate(bool success)
                    {
                        if (dialog == (uint)InstantMessageDialog.StartTyping ||
                            dialog == (uint)InstantMessageDialog.StopTyping)
                        {
                            return;
                        }

                        if ((client != null) && !success)
                        {
                            client.SendInstantMessage(new UUID(im.toAgentID),
                                    "Unable to send instant message. "+
                                    "User is not logged in.",
                                    new UUID(im.fromAgentID), "System",
                                    (byte)InstantMessageDialog.BusyAutoResponse,
                                    (uint)Util.UnixTimeSinceEpoch());
                        }
                    }
                );
            }
        }

        /// <summary>
        ///
        /// </summary>
        /// <param name="msg"></param>
        private void OnGridInstantMessage(GridInstantMessage msg)
        {
            // Just call the Text IM handler above
            // This event won't be raised unless we have that agent,
            // so we can depend on the above not trying to send
            // via grid again
            //
            ProcessInstantMessage(null, msg);
        }
    }
}