/*
 * 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 OpenSimulator 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.Generic;
using System.IO;
using System.Reflection;
using System.Security.Cryptography; // for computing md5 hash
using log4net;
using Mono.Addins;
using Nini.Config;

using OpenMetaverse;
using OpenMetaverse.StructuredData;

using OpenSim.Framework;
using OpenSim.Framework.Servers;
using OpenSim.Framework.Servers.HttpServer;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes;
using OpenSimAssetType = OpenSim.Framework.SLUtil.OpenSimAssetType;

using Ionic.Zlib;

namespace OpenSim.Region.OptionalModules.Materials
{
    [Extension(Path = "/OpenSim/RegionModules", NodeName = "RegionModule", Id = "MaterialsModule")]
    public class MaterialsModule : INonSharedRegionModule, IMaterialsModule
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

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

        public Type ReplaceableInterface { get { return null; } }

        IAssetCache m_cache;
        private Scene m_scene = null;
        private bool m_enabled = false;
        private int m_maxMaterialsPerTransaction = 50;
        private object materialslock = new object();

        public Dictionary<UUID, FaceMaterial> m_Materials = new Dictionary<UUID, FaceMaterial>();
        public Dictionary<UUID, int> m_MaterialsRefCount = new Dictionary<UUID, int>();

        private Dictionary<FaceMaterial, double> m_changed = new Dictionary<FaceMaterial, double>();

        public void Initialise(IConfigSource source)
        {
            m_enabled = true; // default is enabled

            IConfig config = source.Configs["Materials"];
            if (config != null)
            {
                m_enabled = config.GetBoolean("enable_materials", m_enabled);
                m_maxMaterialsPerTransaction = config.GetInt("MaxMaterialsPerTransaction", m_maxMaterialsPerTransaction);
            }

            if (m_enabled)
                m_log.DebugFormat("[Materials]: Initialized");
        }

        public void Close()
        {
            if (!m_enabled)
                return;
        }

        public void AddRegion(Scene scene)
        {
            if (!m_enabled)
                return;

            m_scene = scene;
            m_scene.RegisterModuleInterface<IMaterialsModule>(this);
            m_scene.EventManager.OnRegisterCaps += OnRegisterCaps;
            m_scene.EventManager.OnObjectAddedToScene += EventManager_OnObjectAddedToScene;
            m_scene.EventManager.OnObjectBeingRemovedFromScene += EventManager_OnObjectDeleteFromScene;
            m_scene.EventManager.OnBackup += EventManager_OnBackup;
        }

        public void RemoveRegion(Scene scene)
        {
            if (!m_enabled)
                return;

            m_scene.EventManager.OnRegisterCaps -= OnRegisterCaps;
            m_scene.EventManager.OnObjectAddedToScene -= EventManager_OnObjectAddedToScene;
            m_scene.EventManager.OnObjectBeingRemovedFromScene -= EventManager_OnObjectDeleteFromScene;
            m_scene.EventManager.OnBackup -= EventManager_OnBackup;
            m_scene.UnregisterModuleInterface<IMaterialsModule>(this);
        }

        public void RegionLoaded(Scene scene)
        {
            if (!m_enabled) return;

            m_cache = scene.RequestModuleInterface<IAssetCache>();
            ISimulatorFeaturesModule featuresModule = scene.RequestModuleInterface<ISimulatorFeaturesModule>();
            if (featuresModule != null)
                featuresModule.OnSimulatorFeaturesRequest += OnSimulatorFeaturesRequest;
        }

        private void EventManager_OnBackup(ISimulationDataService datastore, bool forcedBackup)
        {
            List<FaceMaterial> toStore;

            lock (materialslock)
            {
                if(m_changed.Count == 0)
                    return;

                if(forcedBackup)
                {
                    toStore = new List<FaceMaterial>(m_changed.Keys);
                    m_changed.Clear();
                }
                else
                {
                    toStore = new List<FaceMaterial>();
                    double storetime = Util.GetTimeStamp() - 60.0;
                    foreach(KeyValuePair<FaceMaterial, double> kvp in m_changed)
                    {
                        if(kvp.Value < storetime)
                        {
                            toStore.Add(kvp.Key);
                        }
                    }
                    foreach(FaceMaterial fm  in toStore)
                    {
                        m_changed.Remove(fm);
                    }
                }

            if(toStore.Count > 0)
                Util.FireAndForget(delegate
                {
                    foreach(FaceMaterial fm in toStore)
                    {
                        AssetBase a = MakeAsset(fm, false);
                        m_scene.AssetService.Store(a);
                    }
                });
            }
        }

        private void EventManager_OnObjectAddedToScene(SceneObjectGroup obj)
        {
            foreach (var part in obj.Parts)
                if (part != null)
                    GetStoredMaterialsInPart(part);
        }

        private void EventManager_OnObjectDeleteFromScene(SceneObjectGroup obj)
        {
            foreach (var part in obj.Parts)
                if (part != null)
                    RemoveMaterialsInPart(part);
        }

        private void OnRegisterCaps(OpenMetaverse.UUID agentID, OpenSim.Framework.Capabilities.Caps caps)
        {
            string capsBase = "/CAPS/" + caps.CapsObjectPath;

            IRequestHandler renderMaterialsPostHandler
                = new RestStreamHandler("POST", capsBase + "/",
                    (request, path, param, httpRequest, httpResponse)
                        => RenderMaterialsPostCap(request, agentID),
                    "RenderMaterials", null);
            caps.RegisterHandler("RenderMaterials", renderMaterialsPostHandler);

            // OpenSimulator CAPs infrastructure seems to be somewhat hostile towards any CAP that requires both GET
            // and POST handlers, (at least at the time this was originally written), so we first set up a POST
            // handler normally and then add a GET handler via MainServer

            IRequestHandler renderMaterialsGetHandler
                = new RestStreamHandler("GET", capsBase + "/",
                    (request, path, param, httpRequest, httpResponse)
                        => RenderMaterialsGetCap(request),
                    "RenderMaterials", null);
            MainServer.Instance.AddStreamHandler(renderMaterialsGetHandler);

            // materials viewer seems to use either POST or PUT, so assign POST handler for PUT as well
            IRequestHandler renderMaterialsPutHandler
                = new RestStreamHandler("PUT", capsBase + "/",
                    (request, path, param, httpRequest, httpResponse)
                        => RenderMaterialsPutCap(request, agentID),
                    "RenderMaterials", null);
            MainServer.Instance.AddStreamHandler(renderMaterialsPutHandler);
        }

        private void OnSimulatorFeaturesRequest(UUID agentID, ref OSDMap features)
        {
            features["MaxMaterialsPerTransaction"] = m_maxMaterialsPerTransaction;
        }

        /// <summary>
        /// Finds any legacy materials stored in DynAttrs that may exist for this part and add them to 'm_regionMaterials'.
        /// </summary>
        /// <param name="part"></param>
        private bool GetLegacyStoredMaterialsInPart(SceneObjectPart part)
        {
            if (part.DynAttrs == null)
                return false;

            OSD OSMaterials = null;
            OSDArray matsArr = null;

            bool partchanged = false;

            lock (part.DynAttrs)
            {
                if (part.DynAttrs.ContainsStore("OpenSim", "Materials"))
                {
                    OSDMap materialsStore = part.DynAttrs.GetStore("OpenSim", "Materials");

                    if (materialsStore == null)
                        return false;

                    materialsStore.TryGetValue("Materials", out OSMaterials);
                    part.DynAttrs.RemoveStore("OpenSim", "Materials");
                    partchanged = true;
                }

                if (OSMaterials != null && OSMaterials is OSDArray)
                    matsArr = OSMaterials as OSDArray;
                else
                    return partchanged;
            }

            if (matsArr == null)
                return partchanged;
            
            foreach (OSD elemOsd in matsArr)
            {
                if (elemOsd != null && elemOsd is OSDMap)
                {
                    OSDMap matMap = elemOsd as OSDMap;
                    if (matMap.ContainsKey("ID") && matMap.ContainsKey("Material"))
                    {
                        try
                        {
                            lock (materialslock)
                            {
                                UUID id = matMap["ID"].AsUUID();
                                if(m_Materials.ContainsKey(id))
                                    continue;

                                OSDMap theMatMap = (OSDMap)matMap["Material"];
                                FaceMaterial fmat = new FaceMaterial(theMatMap);

                                if(fmat == null ||
                                        ( fmat.DiffuseAlphaMode == 1
                                        && fmat.NormalMapID == UUID.Zero
                                        && fmat.SpecularMapID == UUID.Zero))
                                    continue;
                               
                                fmat.ID = id; 
                                m_Materials[id] = fmat;
                                m_MaterialsRefCount[id] = 0;
                            }
                        }
                        catch (Exception e)
                        {
                            m_log.Warn("[Materials]: exception decoding persisted legacy material: " + e.ToString());
                        }
                    }
                }
            }
            return partchanged;
        }

        /// <summary>
        /// Find the materials used in the SOP, and add them to 'm_regionMaterials'.
        /// </summary>
        private void GetStoredMaterialsInPart(SceneObjectPart part)
        {
            if (part.Shape == null)
                return;

            bool partchanged = false;
            bool facechanged = false;
            var te = new Primitive.TextureEntry(part.Shape.TextureEntry, 0, part.Shape.TextureEntry.Length);
            if (te == null)
                return;

            partchanged = GetLegacyStoredMaterialsInPart(part);

            if (te.DefaultTexture != null)
                facechanged = GetStoredMaterialInFace(part, te.DefaultTexture);
            else
                m_log.WarnFormat(
                    "[Materials]: Default texture for part {0} (part of object {1}) in {2} unexpectedly null.  Ignoring.",
                    part.Name, part.ParentGroup.Name, m_scene.Name);

            foreach (Primitive.TextureEntryFace face in te.FaceTextures)
            {
                if (face != null)
                    facechanged |= GetStoredMaterialInFace(part, face);
            }

            if(facechanged)
                part.Shape.TextureEntry = te.GetBytes(9);

            if(facechanged || partchanged)
            {
                if (part.ParentGroup != null && !part.ParentGroup.IsDeleted)
                    part.ParentGroup.HasGroupChanged = true;
            }
        }

        /// <summary>
        /// Find the materials used in one Face, and add them to 'm_regionMaterials'.
        /// </summary>
        private bool GetStoredMaterialInFace(SceneObjectPart part, Primitive.TextureEntryFace face)
        {
            UUID id = face.MaterialID;
            if (id == UUID.Zero)
                return false;

            OSDMap mat;
            lock (materialslock)
            {
                if(m_Materials.ContainsKey(id))
                {
                    m_MaterialsRefCount[id]++;
                    return false;
                }

                AssetBase matAsset = m_scene.AssetService.Get(id.ToString());
                if (matAsset == null || matAsset.Data == null || matAsset.Data.Length == 0 )
                {
                    // grid may just be down...
                    return false;
                }

                byte[] data = matAsset.Data;

                // string txt = System.Text.Encoding.ASCII.GetString(data);
                try
                {
                    mat = (OSDMap)OSDParser.DeserializeLLSDXml(data);
                }
                catch (Exception e)
                {
                    m_log.WarnFormat("[Materials]: cannot decode material asset {0}: {1}", id, e.Message);
                    return false;
                }

                FaceMaterial fmat = new FaceMaterial(mat);

                if(fmat == null ||
                        (fmat.DiffuseAlphaMode == 1
                        && fmat.NormalMapID == UUID.Zero
                        && fmat.SpecularMapID == UUID.Zero))
                {
                        face.MaterialID = UUID.Zero;
                        return true;
                }

                fmat.ID = id;

                if (m_Materials.ContainsKey(id))
                {
                    m_MaterialsRefCount[id]++;
                }
                else
                {
                    m_Materials[id] = fmat;
                    m_MaterialsRefCount[id] = 1;
                }
                return false;
            }
        }

        private void RemoveMaterialsInPart(SceneObjectPart part)
        {
            if (part.Shape == null)
                return;

            var te = new Primitive.TextureEntry(part.Shape.TextureEntry, 0, part.Shape.TextureEntry.Length);
            if (te == null)
                return;

            if (te.DefaultTexture != null)
                RemoveMaterialInFace(te.DefaultTexture);

            foreach (Primitive.TextureEntryFace face in te.FaceTextures)
            {
                if(face != null)
                    RemoveMaterialInFace(face);
            }
        }

       private void RemoveMaterialInFace(Primitive.TextureEntryFace face)
        {
            UUID id = face.MaterialID;
            if (id == UUID.Zero)
                return;

            lock (materialslock)
            {
                if(!m_Materials.ContainsKey(id))
                    return;
                else
                {
                    m_MaterialsRefCount[id]--;
                    if(m_MaterialsRefCount[id] <= 0)
                    {
                        FaceMaterial oldFaceMat = m_Materials[id];
                        m_changed.Remove(oldFaceMat);
                        m_Materials.Remove(id);
                        m_MaterialsRefCount.Remove(id);
                        m_cache.Expire(id.ToString());
                    }
                }
            }
        }

        public string RenderMaterialsPostCap(string request, UUID agentID)
        {
            OSDMap req = (OSDMap)OSDParser.DeserializeLLSDXml(request);
            OSDMap resp = new OSDMap();

            OSDArray respArr = new OSDArray();

            if (req.ContainsKey("Zipped"))
            {
                OSD osd = null;

                byte[] inBytes = req["Zipped"].AsBinary();

                try
                {
                    osd = ZDecompressBytesToOsd(inBytes);

                    if (osd != null && osd is OSDArray)
                    {
                        foreach (OSD elem in (OSDArray)osd)
                        {
                            try
                            {
                                UUID id = new UUID(elem.AsBinary(), 0);

                                lock (materialslock)
                                {
                                    if (m_Materials.ContainsKey(id))
                                    {
                                        OSDMap matMap = new OSDMap();
                                        matMap["ID"] = OSD.FromBinary(id.GetBytes());
                                        matMap["Material"] = m_Materials[id].toOSD();
                                        respArr.Add(matMap);
                                    }
                                    else
                                    {
                                        m_log.Warn("[Materials]: request for unknown material ID: " + id.ToString());

                                        // Theoretically we could try to load the material from the assets service,
                                        // but that shouldn't be necessary because the viewer should only request
                                        // materials that exist in a prim on the region, and all of these materials
                                        // are already stored in m_regionMaterials.
                                    }
                                }
                            }
                            catch (Exception e)
                            {
                                m_log.Error("Error getting materials in response to viewer request", e);
                                continue;
                            }
                        }
                    }
                }
                catch (Exception e)
                {
                    m_log.Warn("[Materials]: exception decoding zipped CAP payload ", e);
                    //return "";
                }
            }

            resp["Zipped"] = ZCompressOSD(respArr, false);
            string response = OSDParser.SerializeLLSDXmlString(resp);

            //m_log.Debug("[Materials]: cap request: " + request);
            //m_log.Debug("[Materials]: cap request (zipped portion): " + ZippedOsdBytesToString(req["Zipped"].AsBinary()));
            //m_log.Debug("[Materials]: cap response: " + response);
            return response;
        }

        public string RenderMaterialsPutCap(string request, UUID agentID)
        {
            OSDMap req = (OSDMap)OSDParser.DeserializeLLSDXml(request);
            OSDMap resp = new OSDMap();

            OSDMap materialsFromViewer = null;

            OSDArray respArr = new OSDArray();

            HashSet<SceneObjectPart> parts = new HashSet<SceneObjectPart>();
            if (req.ContainsKey("Zipped"))
            {
                OSD osd = null;

                byte[] inBytes = req["Zipped"].AsBinary();

                try
                {
                    osd = ZDecompressBytesToOsd(inBytes);

                    if (osd != null && osd is OSDMap)
                    {
                        materialsFromViewer = osd as OSDMap;

                        if (materialsFromViewer.ContainsKey("FullMaterialsPerFace"))
                        {
                            OSD matsOsd = materialsFromViewer["FullMaterialsPerFace"];
                            if (matsOsd is OSDArray)
                            {
                                OSDArray matsArr = matsOsd as OSDArray;

                                try
                                {
                                    foreach (OSDMap matsMap in matsArr)
                                    {
                                        uint primLocalID = 0;
                                        try
                                        {
                                            primLocalID = matsMap["ID"].AsUInteger();
                                        }
                                        catch (Exception e)
                                        {
                                            m_log.Warn("[Materials]: cannot decode \"ID\" from matsMap: " + e.Message);
                                            continue;
                                        }

                                        SceneObjectPart sop = m_scene.GetSceneObjectPart(primLocalID);
                                        if (sop == null)
                                        {
                                            m_log.WarnFormat("[Materials]: SOP not found for localId: {0}", primLocalID.ToString());
                                            continue;
                                        }

                                        if (!m_scene.Permissions.CanEditObject(sop.UUID, agentID))
                                        {
                                            m_log.WarnFormat("User {0} can't edit object {1} {2}", agentID, sop.Name, sop.UUID);
                                            continue;
                                        }

                                        OSDMap mat = null;
                                        try
                                        {
                                            mat = matsMap["Material"] as OSDMap;
                                        }
                                        catch (Exception e)
                                        {
                                            m_log.Warn("[Materials]: cannot decode \"Material\" from matsMap: " + e.Message);
                                            continue;
                                        }

                                        Primitive.TextureEntry te = new Primitive.TextureEntry(sop.Shape.TextureEntry, 0, sop.Shape.TextureEntry.Length);
                                        if (te == null)
                                        {
                                            m_log.WarnFormat("[Materials]: Error in TextureEntry for SOP {0} {1}", sop.Name, sop.UUID);
                                            continue;
                                        }

                                        int face = -1;
                                        UUID oldid = UUID.Zero;
                                        Primitive.TextureEntryFace faceEntry = null;
                                        if (matsMap.ContainsKey("Face"))
                                        {
                                            face = matsMap["Face"].AsInteger();
                                            faceEntry = te.CreateFace((uint)face);
                                        }
                                        else
                                            faceEntry = te.DefaultTexture;

                                        if (faceEntry == null)
                                            continue;

                                        UUID id;
                                        FaceMaterial newFaceMat = null;
                                        if (mat == null)
                                        {
                                            // This happens then the user removes a material from a prim
                                            id = UUID.Zero;
                                        }
                                        else
                                        {
                                            newFaceMat = new FaceMaterial(mat);
                                            if(newFaceMat.DiffuseAlphaMode == 1 
                                                    && newFaceMat.NormalMapID == UUID.Zero 
                                                    && newFaceMat.SpecularMapID == UUID.Zero
                                                    )
                                                id = UUID.Zero;
                                            else
                                            {
                                                newFaceMat.genID();
                                                id = newFaceMat.ID;
                                            }
                                        }

                                        oldid = faceEntry.MaterialID;

                                        if(oldid == id)
                                            continue;

                                        if (faceEntry != null)
                                        {
                                            faceEntry.MaterialID = id;
                                            //m_log.DebugFormat("[Materials]: in \"{0}\" {1}, setting material ID for face {2} to {3}", sop.Name, sop.UUID, face, id);
                                            // We can't use sop.UpdateTextureEntry(te) because it filters, so do it manually
                                            sop.Shape.TextureEntry = te.GetBytes(9);
                                        }

                                        if(oldid != UUID.Zero)
                                            RemoveMaterial(oldid);

                                        lock(materialslock)
                                        {
                                            if(id != UUID.Zero)
                                            {
                                                if (m_Materials.ContainsKey(id))
                                                    m_MaterialsRefCount[id]++;
                                                else
                                                {
                                                    m_Materials[id] = newFaceMat;
                                                    m_MaterialsRefCount[id] = 1;
                                                    m_changed[newFaceMat] = Util.GetTimeStamp();
                                                }
                                            }
                                        }

                                        if(!parts.Contains(sop))
                                            parts.Add(sop);
                                    }

                                    foreach(SceneObjectPart sop in parts)
                                    {
                                        if (sop.ParentGroup != null && !sop.ParentGroup.IsDeleted)
                                        {
                                            sop.TriggerScriptChangedEvent(Changed.TEXTURE);
                                            sop.ScheduleFullUpdate();
                                            sop.ParentGroup.HasGroupChanged = true;
                                        }
                                    }
                                }
                                catch (Exception e)
                                {
                                    m_log.Warn("[Materials]: exception processing received material ", e);
                                }
                            }
                        }
                    }
                }
                catch (Exception e)
                {
                    m_log.Warn("[Materials]: exception decoding zipped CAP payload ", e);
                    //return "";
                }
            }

            resp["Zipped"] = ZCompressOSD(respArr, false);
            string response = OSDParser.SerializeLLSDXmlString(resp);

            //m_log.Debug("[Materials]: cap request: " + request);
            //m_log.Debug("[Materials]: cap request (zipped portion): " + ZippedOsdBytesToString(req["Zipped"].AsBinary()));
            //m_log.Debug("[Materials]: cap response: " + response);
            return response;
        }

        private AssetBase MakeAsset(FaceMaterial fm, bool local)
        {
            // this are not true assets, should had never been...
            AssetBase asset = null;
            string txt = fm.toLLSDxml();
            byte[] data = System.Text.Encoding.ASCII.GetBytes(txt);

            asset = new AssetBase(fm.ID, "llmaterial", (sbyte)OpenSimAssetType.Material, "00000000-0000-0000-0000-000000000000");
            asset.Data = data;
            asset.Local = local;
            return asset;
        }

        public string RenderMaterialsGetCap(string request)
        {
            OSDMap resp = new OSDMap();
            OSDArray allOsd = new OSDArray();
/*
            // this violates all idea of caching and geting things only if needed, so disabled

            int matsCount = 0;
            lock (m_Materials)
            {
                foreach (KeyValuePair<UUID, FaceMaterial> kvp in m_Materials)
                {
                    OSDMap matMap = new OSDMap();
                    matMap["ID"] = OSD.FromBinary(kvp.Key.GetBytes());
                    matMap["Material"] = kvp.Value.toOSD();
                    allOsd.Add(matMap);
                    matsCount++;
                }
            }
*/
            resp["Zipped"] = ZCompressOSD(allOsd, false);

            return OSDParser.SerializeLLSDXmlString(resp);
        }

        private static string ZippedOsdBytesToString(byte[] bytes)
        {
            try
            {
                return OSDParser.SerializeJsonString(ZDecompressBytesToOsd(bytes));
            }
            catch (Exception e)
            {
                return "ZippedOsdBytesToString caught an exception: " + e.ToString();
            }
        }

        public static OSD ZCompressOSD(OSD inOsd, bool useHeader)
        {
            OSD osd = null;

            byte[] data = OSDParser.SerializeLLSDBinary(inOsd, useHeader);

            using (MemoryStream msSinkCompressed = new MemoryStream())
            {
                using (Ionic.Zlib.ZlibStream zOut = new Ionic.Zlib.ZlibStream(msSinkCompressed,
                    Ionic.Zlib.CompressionMode.Compress, CompressionLevel.BestCompression, true))
                {
                    zOut.Write(data, 0, data.Length);
                }

                msSinkCompressed.Seek(0L, SeekOrigin.Begin);
                osd = OSD.FromBinary(msSinkCompressed.ToArray());
            }

            return osd;
        }

        public static OSD ZDecompressBytesToOsd(byte[] input)
        {
            OSD osd = null;

            using (MemoryStream msSinkUnCompressed = new MemoryStream())
            {
                using (Ionic.Zlib.ZlibStream zOut = new Ionic.Zlib.ZlibStream(msSinkUnCompressed, CompressionMode.Decompress, true))
                {
                    zOut.Write(input, 0, input.Length);
                }

                msSinkUnCompressed.Seek(0L, SeekOrigin.Begin);
                osd = OSDParser.DeserializeLLSDBinary(msSinkUnCompressed.ToArray());
            }

            return osd;
        }

        public FaceMaterial GetMaterial(UUID ID)
        {
            FaceMaterial fm = null;
            if(m_Materials.TryGetValue(ID, out fm))
                return fm;
            return null;
        }

        public FaceMaterial GetMaterialCopy(UUID ID)
        {
            FaceMaterial fm = null;
            if(m_Materials.TryGetValue(ID, out fm))
                return new FaceMaterial(fm);
            return null;
        }

        public UUID AddNewMaterial(FaceMaterial fm)
        {
            if(fm.DiffuseAlphaMode == 1 && fm.NormalMapID == UUID.Zero && fm.SpecularMapID == UUID.Zero)
            {
                fm.ID = UUID.Zero;
                return UUID.Zero;
            }

            fm.genID();
            UUID id = fm.ID;
            lock(materialslock)
            {
                if(m_Materials.ContainsKey(id))
                    m_MaterialsRefCount[id]++;
                else
                {
                    m_Materials[id] = fm;
                    m_MaterialsRefCount[id] = 1;
                    m_changed[fm] = Util.GetTimeStamp();
                }
            }
            return id;
        }

        public void RemoveMaterial(UUID id)
        {
            if(id == UUID.Zero)
                return;

            lock(materialslock)
            {
                if(m_Materials.ContainsKey(id))
                {
                    m_MaterialsRefCount[id]--;
                    if(m_MaterialsRefCount[id] <= 0)
                    {
                        FaceMaterial fm = m_Materials[id];
                        m_changed.Remove(fm);
                        m_Materials.Remove(id);
                        m_MaterialsRefCount.Remove(id);
                        m_cache.Expire(id.ToString());
                    }
                }
            }
        }
    }
}