/*
* 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.Generic;
using System.IO;
using System.Threading;
using System.Xml;
using libsecondlife;
using Nini.Config;
using OpenSim.Framework.Console;

namespace OpenSim.Framework.Communications.Cache
{
    public abstract class AssetServerBase : IAssetServer
    {
        protected IAssetReceiver _receiver;
        protected BlockingQueue<AssetRequest> _assetRequests;
        protected Thread _localAssetServerThread;
        protected IAssetProvider m_assetProviderPlugin;
        protected object syncLock = new object();

        protected abstract void StoreAsset(AssetBase asset);
        protected abstract void CommitAssets();

        /// <summary>
        /// This method must be implemented by a subclass to retrieve the asset named in the 
        /// AssetRequest.  If the asset is not found, null should be returned.
        /// </summary>
        /// <param name="req"></param>
        /// <returns></returns>
        protected abstract AssetBase GetAsset(AssetRequest req);

        /// <summary>
        /// Process an asset request.  This method will call GetAsset(AssetRequest req) 
        /// on the subclass.
        /// </summary>
        /// <param name="req"></param>
        protected virtual void ProcessRequest(AssetRequest req)
        {
            AssetBase asset = GetAsset(req);

            if (asset != null)
            {
                MainLog.Instance.Verbose(
                    "ASSET", "Asset {0} received from asset server", req.AssetID);

                _receiver.AssetReceived(asset, req.IsTexture);
            }
            else
            {
                MainLog.Instance.Error(
                    "ASSET", "Asset {0} not found by asset server", req.AssetID);

                _receiver.AssetNotFound(req.AssetID);
            }
        }

        public void LoadDefaultAssets()
        {
            MainLog.Instance.Verbose("ASSETSERVER", "Setting up asset database");

            ForEachDefaultAsset(StoreAsset);
            ForEachXmlAsset(StoreAsset);

            CommitAssets();
        }


        public AssetServerBase()
        {
            MainLog.Instance.Verbose("ASSETSERVER", "Starting asset storage system");
            _assetRequests = new BlockingQueue<AssetRequest>();

            _localAssetServerThread = new Thread(RunRequests);
            _localAssetServerThread.IsBackground = true;
            _localAssetServerThread.Start();
        }

        private void RunRequests()
        {
            while (true) // Since it's a 'blocking queue'
            {
                try
                {
                    AssetRequest req = _assetRequests.Dequeue();

                    ProcessRequest(req);
                }
                catch (Exception e)
                {
                    MainLog.Instance.Error("ASSETSERVER", e.Message);
                }
            }
        }

        public void LoadAsset(AssetBase info, bool image, string filename)
        {
            //should request Asset from storage manager
            //but for now read from file

            string dataPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "assets"); //+ folder;
            string fileName = Path.Combine(dataPath, filename);
            FileInfo fInfo = new FileInfo(fileName);
            long numBytes = fInfo.Length;
            FileStream fStream = new FileStream(fileName, FileMode.Open, FileAccess.Read);
            byte[] idata = new byte[numBytes];
            BinaryReader br = new BinaryReader(fStream);
            idata = br.ReadBytes((int) numBytes);
            br.Close();
            fStream.Close();
            info.Data = idata;
            //info.loaded=true;
        }

        public void SetReceiver(IAssetReceiver receiver)
        {
            _receiver = receiver;
        }

        public void RequestAsset(LLUUID assetID, bool isTexture)
        {
            AssetRequest req = new AssetRequest();
            req.AssetID = assetID;
            req.IsTexture = isTexture;
            _assetRequests.Enqueue(req);

            MainLog.Instance.Verbose("ASSET", "Added {0} to request queue", assetID);
        }

        public virtual void UpdateAsset(AssetBase asset)
        {
            lock (syncLock)
            {
                m_assetProviderPlugin.UpdateAsset(asset);
                m_assetProviderPlugin.CommitAssets();
            }
        }

        public void StoreAndCommitAsset(AssetBase asset)
        {
            lock (syncLock)
            {
                StoreAsset(asset);
                CommitAssets();
            }
        }

        public virtual void Close()
        {
            _localAssetServerThread.Abort();
        }

        public void SetServerInfo(string ServerUrl, string ServerKey)
        {
        }

        public virtual List<AssetBase> GetDefaultAssets()
        {
            List<AssetBase> assets = new List<AssetBase>();
            return assets;
        }

        public AssetBase CreateImageAsset(string assetIdStr, string name, string filename)
        {
            return CreateAsset(assetIdStr, name, filename, true);
        }

        public void ForEachDefaultAsset(Action<AssetBase> action)
        {
            List<AssetBase> assets = GetDefaultAssets();
            assets.ForEach(action);
        }

        public AssetBase CreateAsset(string assetIdStr, string name, string filename, bool isImage)
        {
            AssetBase asset = new AssetBase(
                new LLUUID(assetIdStr),
                name
                );

            if (!String.IsNullOrEmpty(filename))
            {
                MainLog.Instance.Verbose("ASSETS", "Loading: [{0}][{1}]", name, filename);

                LoadAsset(asset, isImage, filename);
            }
            else
            {
                MainLog.Instance.Verbose("ASSETS", "Instantiated: [{0}]", name);
            }

            return asset;
        }

        public void ForEachXmlAsset(Action<AssetBase> action)
        {
            List<AssetBase> assets = new List<AssetBase>();
            // System.Console.WriteLine("trying loading asset into database");
            string filePath = Path.Combine(Util.configDir(), "OpenSimAssetSet.xml");
            if (File.Exists(filePath))
            {
                try
                {
                    XmlConfigSource source = new XmlConfigSource(filePath);

                    for (int i = 0; i < source.Configs.Count; i++)
                    {
                        // System.Console.WriteLine("loading asset into database");
                        string assetIdStr = source.Configs[i].GetString("assetID", LLUUID.Random().ToString());
                        string name = source.Configs[i].GetString("name", "");
                        sbyte type = (sbyte) source.Configs[i].GetInt("assetType", 0);
                        sbyte invType = (sbyte) source.Configs[i].GetInt("inventoryType", 0);
                        string fileName = source.Configs[i].GetString("fileName", "");

                        AssetBase newAsset = CreateAsset(assetIdStr, name, fileName, false);

                        newAsset.Type = type;
                        newAsset.InvType = invType;
                        assets.Add(newAsset);
                    }
                }
                catch (XmlException e)
                {
                    MainLog.Instance.Error("ASSETS", "Error loading " + filePath + ": " + e.ToString());
                }
            }
            assets.ForEach(action);
        }
    }
}