/*
 * 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;
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 * 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.Generic;
using System.Threading;
using libsecondlife;
using Nini.Config;
using OpenSim.Framework;
using OpenSim.Framework.Communications.Cache;
using OpenSim.Region.Environment.Interfaces;
using OpenSim.Region.Environment.Scenes;
using OpenSim.Framework.Data.Base;
using OpenSim.Framework.Data.MapperFactory;

namespace OpenSim.Region.Modules.AvatarFactory
{
    public class AvatarFactoryModule : IAvatarFactory, IRegionModule
    {
        private Scene m_scene = null;
        private readonly Dictionary<LLUUID, AvatarAppearance> m_avatarsAppearance = new Dictionary<LLUUID, AvatarAppearance>();

        private bool m_enablePersist = false;
        private string m_connectionString;
        private bool m_configured = false;
        private BaseDatabaseConnector m_databaseMapper;
        private AppearanceTableMapper m_appearanceMapper;

        private Dictionary<LLUUID, EventWaitHandle> m_fetchesInProgress = new Dictionary<LLUUID, EventWaitHandle>();
        private object m_syncLock = new object();

        public bool TryGetAvatarAppearance(LLUUID avatarId, out AvatarAppearance appearance)
        {

            //should only let one thread at a time do this part
            EventWaitHandle waitHandle = null;
            bool fetchInProgress = false;
            lock (m_syncLock)
            {
                appearance = CheckCache(avatarId);
                if (appearance != null)
                {
                    return true;
                }

                //not in cache so check to see if another thread is already fetching it
                if (m_fetchesInProgress.TryGetValue(avatarId, out waitHandle))
                {
                    fetchInProgress = true;
                }
                else
                {
                    fetchInProgress = false;

                    //no thread already fetching this appearance, so add a wait handle to list
                    //for any following threads that want the same appearance
                    waitHandle = new EventWaitHandle(false, EventResetMode.ManualReset);
                    m_fetchesInProgress.Add(avatarId, waitHandle);
                }
            }

            if (fetchInProgress)
            {
                waitHandle.WaitOne();
                appearance = CheckCache(avatarId);
                if (appearance != null)
                {
                    waitHandle = null;
                    return true;
                }
                else
                {
                    waitHandle = null;
                    return false;
                }
            }
            else
            {
                Thread.Sleep(5000); //why is this here? 

                //this is the first thread to request this appearance
                //so let it check the db and if not found then create a default appearance
                //and add that to the cache
                appearance = CheckDatabase(avatarId);
                if (appearance != null)
                {
                    //appearance has now been added to cache so lets pulse any waiting threads
                    lock (m_syncLock)
                    {
                        m_fetchesInProgress.Remove(avatarId);
                        waitHandle.Set();
                    }
                    // waitHandle.Close();
                    waitHandle = null;
                    return true;
                }

                //not found a appearance for the user, so create a new default one
                appearance = CreateDefault(avatarId);
                if (appearance != null)
                {
                    //update database
                    if (m_enablePersist)
                    {
                        m_appearanceMapper.Add(avatarId.UUID, appearance);
                    }

                    //add appearance to dictionary cache
                    lock (m_avatarsAppearance)
                    {
                        m_avatarsAppearance[avatarId] = appearance;
                    }

                    //appearance has now been added to cache so lets pulse any waiting threads
                    lock (m_syncLock)
                    {
                        m_fetchesInProgress.Remove(avatarId);
                        waitHandle.Set();
                    }
                    // waitHandle.Close();
                    waitHandle = null;
                    return true;
                }
                else
                {
                    //something went wrong, so release the wait handle and remove it
                    //all waiting threads will fail to find cached appearance
                    //but its better for them to fail than wait for ever
                    lock (m_syncLock)
                    {
                        m_fetchesInProgress.Remove(avatarId);
                        waitHandle.Set();
                    }
                    //waitHandle.Close();
                    waitHandle = null;
                    return false;
                }
            }
        }

        private AvatarAppearance CreateDefault(LLUUID avatarId)
        {
            AvatarAppearance appearance = null;
            AvatarWearable[] wearables;
            byte[] visualParams;
            GetDefaultAvatarAppearance(out wearables, out visualParams);
            appearance = new AvatarAppearance(avatarId, wearables, visualParams);

            return appearance;
        }

        private AvatarAppearance CheckDatabase(LLUUID avatarId)
        {
            AvatarAppearance appearance = null;
            if (m_enablePersist)
            {
                if (m_appearanceMapper.TryGetValue(avatarId.UUID, out appearance))
                {
                    appearance.VisualParams = GetDefaultVisualParams();
                    appearance.TextureEntry = AvatarAppearance.GetDefaultTextureEntry();
                    lock (m_avatarsAppearance)
                    {
                        m_avatarsAppearance[avatarId] = appearance;
                    }
                }
            }
            return appearance;
        }

        private AvatarAppearance CheckCache(LLUUID avatarId)
        {
            AvatarAppearance appearance = null;
            lock (m_avatarsAppearance)
            {
                if (m_avatarsAppearance.ContainsKey(avatarId))
                {
                    appearance = m_avatarsAppearance[avatarId];
                }
            }
            return appearance;
        }

        public void Initialise(Scene scene, IConfigSource source)
        {
            scene.RegisterModuleInterface<IAvatarFactory>(this);
            scene.EventManager.OnNewClient += NewClient;

            if (m_scene == null)
            {
                m_scene = scene;
            }

            if (!m_configured)
            {
                m_configured = true;
                try
                {
                    m_enablePersist = source.Configs["Startup"].GetBoolean("appearance_persist", false);
                }
                catch (Exception)
                {
                }
                if (m_enablePersist)
                {
                    m_connectionString = source.Configs["Startup"].GetString("appearance_connection_string", "");

                    string mapperTypeStr = source.Configs["Startup"].GetString("appearance_database", "MySQL");

                    DataMapperFactory.MAPPER_TYPE mapperType =
                        (DataMapperFactory.MAPPER_TYPE)
                        Enum.Parse(typeof (DataMapperFactory.MAPPER_TYPE), mapperTypeStr);

                    m_databaseMapper = DataMapperFactory.GetDataBaseMapper(mapperType, m_connectionString);

                    m_appearanceMapper = new AppearanceTableMapper(m_databaseMapper, "AvatarAppearance");
                }
            }
        }

        public void PostInitialise()
        {
        }

        public void Close()
        {
        }

        public string Name
        {
            get { return "Default Avatar Factory"; }
        }

        public bool IsSharedModule
        {
            get { return true; }
        }

        public void NewClient(IClientAPI client)
        {
            client.OnAvatarNowWearing += AvatarIsWearing;
        }

        public void RemoveClient(IClientAPI client)
        {
            // client.OnAvatarNowWearing -= AvatarIsWearing;
        }

        public void AvatarIsWearing(Object sender, AvatarWearingArgs e)
        {
            IClientAPI clientView = (IClientAPI)sender;
            CachedUserInfo profile = m_scene.CommsManager.UserProfileCacheService.GetUserDetails(clientView.AgentId);
            if (profile != null)
            {
                if (profile.RootFolder != null)
                {
                    if (m_avatarsAppearance.ContainsKey(clientView.AgentId))
                    {
                        AvatarAppearance avatAppearance = null;
                        lock (m_avatarsAppearance)
                        {
                            avatAppearance = m_avatarsAppearance[clientView.AgentId];
                        }

                        foreach (AvatarWearingArgs.Wearable wear in e.NowWearing)
                        {
                            if (wear.Type < 13)
                            {
                                if (wear.ItemID == LLUUID.Zero)
                                {
                                    avatAppearance.Wearables[wear.Type].ItemID = LLUUID.Zero;
                                    avatAppearance.Wearables[wear.Type].AssetID = LLUUID.Zero;

                                    UpdateDatabase(clientView.AgentId, avatAppearance);
                                }
                                else
                                {
                                    LLUUID assetId;

                                    InventoryItemBase baseItem = profile.RootFolder.HasItem(wear.ItemID);
                                    if (baseItem != null)
                                    {
                                        assetId = baseItem.assetID;
                                        avatAppearance.Wearables[wear.Type].AssetID = assetId;
                                        avatAppearance.Wearables[wear.Type].ItemID = wear.ItemID;

                                        UpdateDatabase(clientView.AgentId, avatAppearance);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        public void UpdateDatabase(LLUUID userID, AvatarAppearance avatAppearance)
        {
            if (m_enablePersist)
            {
                m_appearanceMapper.Update(userID.UUID, avatAppearance);
            }
        }

        public static void GetDefaultAvatarAppearance(out AvatarWearable[] wearables, out byte[] visualParams)
        {
            visualParams = GetDefaultVisualParams();
            wearables = AvatarWearable.DefaultWearables;
        }

        private static byte[] GetDefaultVisualParams()
        {
            byte[] visualParams;
            visualParams = new byte[218];
            for (int i = 0; i < 218; i++)
            {
                visualParams[i] = 100;
            }
            return visualParams;
        }
    }
}