/*
 * 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.Reflection;
using System.Threading;
using System.Collections.Generic;
using log4net;
using Nini.Config;
using OpenMetaverse;
using OpenMetaverse.Imaging;
using OpenSim.Region.Environment.Interfaces;
using OpenSim.Region.Environment.Scenes;

namespace OpenSim.Region.Environment.Modules.Agent.TextureSender
{
    public class J2KDecoderModule : IRegionModule, IJ2KDecoder
    {
        #region IRegionModule Members

        private static readonly ILog m_log
            = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Cached Decoded Layers
        /// </summary>
        private readonly Dictionary<UUID, OpenJPEG.J2KLayerInfo[]> m_cacheddecode = new Dictionary<UUID, OpenJPEG.J2KLayerInfo[]>();
        private bool OpenJpegFail = false;

        /// <summary>
        /// List of client methods to notify of results of decode
        /// </summary>
        private readonly Dictionary<UUID, List<DecodedCallback>> m_notifyList = new Dictionary<UUID, List<DecodedCallback>>();

        public void Initialise(Scene scene, IConfigSource source)
        {
            scene.RegisterModuleInterface<IJ2KDecoder>(this);
        }

        public void PostInitialise()
        {
            
        }

        public void Close()
        {
            
        }

        public string Name
        {
            get { return "J2KDecoderModule"; }
        }

        public bool IsSharedModule
        {
            get { return true; }
        }

        #endregion

        #region IJ2KDecoder Members


        public void decode(UUID AssetId, byte[] assetData, DecodedCallback decodedReturn)
        {
            // Dummy for if decoding fails.
            OpenJPEG.J2KLayerInfo[] result = new OpenJPEG.J2KLayerInfo[0];

            // Check if it's cached
            bool cached = false;
            lock (m_cacheddecode)
            {
                if (m_cacheddecode.ContainsKey(AssetId))
                {
                    cached = true;
                    result = m_cacheddecode[AssetId];
                }
            }

            // If it's cached, return the cached results
            if (cached)
            {
                decodedReturn(AssetId, result);
            }
            else
            {
                // not cached, so we need to decode it
                // Add to notify list and start decoding.
                // Next request for this asset while it's decoding will only be added to the notify list
                // once this is decoded, requests will be served from the cache and all clients in the notifylist will be updated
                bool decode = false;
                lock (m_notifyList)
                {
                    if (m_notifyList.ContainsKey(AssetId))
                    {
                        m_notifyList[AssetId].Add(decodedReturn);
                    }
                    else
                    {
                        List<DecodedCallback> notifylist = new List<DecodedCallback>();
                        notifylist.Add(decodedReturn);
                        m_notifyList.Add(AssetId, notifylist);
                        decode = true;
                    }
                }
                // Do Decode!
                if (decode)
                {
                    doJ2kDecode(AssetId, assetData);
                }
            }
        }

        #endregion

        /// <summary>
        /// Decode Jpeg2000 Asset Data
        /// </summary>
        /// <param name="AssetId">UUID of Asset</param>
        /// <param name="j2kdata">Byte Array Asset Data </param>
        private void doJ2kDecode(UUID AssetId, byte[] j2kdata)
        {
            int DecodeTime = 0;
            DecodeTime = System.Environment.TickCount;
            OpenJPEG.J2KLayerInfo[] layers = new OpenJPEG.J2KLayerInfo[0]; // Dummy result for if it fails.  Informs that there's only full quality

            if (!OpenJpegFail)
            {
                try
                {

                    AssetTexture texture = new AssetTexture(AssetId, j2kdata);
                    if (texture.DecodeLayerBoundaries())
                    {
                        bool sane = true;

                        // Sanity check all of the layers
                        for (int i = 0; i < texture.LayerInfo.Length; i++)
                        {
                            if (texture.LayerInfo[i].End > texture.AssetData.Length)
                            {
                                sane = false;
                                break;
                            }
                        }

                        if (sane)
                        {
                            layers = texture.LayerInfo;
                        }
                        else
                        {
                            m_log.WarnFormat(
                                "[J2KDecoderModule]: JPEG2000 texture decoding succeeded, but sanity check failed for {0}",
                                AssetId);
                        }
                    }

                    else
                    {
                        m_log.WarnFormat("[J2KDecoderModule]: JPEG2000 texture decoding failed for {0}", AssetId);
                    }
                    texture = null; // dereference and dispose of ManagedImage
                }
                catch (DllNotFoundException)
                {
                    m_log.Error(
                        "[J2KDecoderModule]: OpenJpeg is not installed properly. Decoding disabled!  This will slow down texture performance!  Often times this is because of an old version of GLIBC.  You must have version 2.4 or above!");
                    OpenJpegFail = true;
                }
                catch (Exception ex)
                {
                    m_log.WarnFormat("[J2KDecoderModule]: JPEG2000 texture decoding threw an exception for {0}, {1}",
                                     AssetId, ex);
                }
            }

            if (!OpenJpegFail)
            {
                // Write out decode time
                m_log.InfoFormat("[J2KDecoderModule]: {0} Decode Time: {1}", System.Environment.TickCount - DecodeTime,
                                 AssetId);
            }
            // Cache Decoded layers
            lock (m_cacheddecode)
            {
                m_cacheddecode.Add(AssetId, layers);

            }

            // Notify Interested Parties
            lock (m_notifyList)
            {
                if (m_notifyList.ContainsKey(AssetId))
                {
                    foreach (DecodedCallback d in m_notifyList[AssetId])
                    {
                        if (d != null)
                            d.DynamicInvoke(AssetId, layers);
                    }
                    m_notifyList.Remove(AssetId);
                }
            }
        }
    }
}