using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xenki.Framework;
using OpenMetaverse;
using System.Drawing;
using System.IO;
using System.Threading;
using OpenMetaverse.Imaging;

namespace Xenki.DefaultRenderer
{

    public class DefaultTexture //: ITextureManage
    {

        private event TextureDownloadFinished onDownloadFinished;

        string cachefolderPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "textures");

        string bmpFilePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "texture");

        //the textures have load in memory.
       // private readonly Dictionary<UUID, byte[]> CurruntTextures = new Dictionary<UUID, byte[]>();

        private Thread MainThread;
        // list of current requests in process
        private Dictionary<UUID, int> CurrentRequests;

        private Queue<UUID> RequestQueue;

        private static AutoResetEvent[] resetEvents;

        private static int[] threadpoolSlots;


        // maximum allowed concurrent requests at once
        const int MAX_TEXTURE_REQUESTS = 3;

        private GridClient gridClient;

        public GridClient GridClient
        {
            get { return gridClient; }
            set
            {
                gridClient = value;

                gridClient.Settings.USE_TEXTURE_CACHE = true;
                if (Directory.Exists(cachefolderPath) == false)
                    Directory.CreateDirectory(cachefolderPath);

                gridClient.Settings.TEXTURE_CACHE_DIR = cachefolderPath;
                gridClient.Settings.TEXTURE_CACHE_MAX_SIZE = 5120;//M? or number?

            }
        }
        private static readonly DefaultTexture singleton = new DefaultTexture();

        public static DefaultTexture SingleTextureManager()
        {
            return singleton;
        }

        private DefaultTexture()
        {
            RequestQueue = new Queue<UUID>();

            CurrentRequests = new Dictionary<UUID, int>(MAX_TEXTURE_REQUESTS);

            resetEvents = new AutoResetEvent[MAX_TEXTURE_REQUESTS];
            threadpoolSlots = new int[MAX_TEXTURE_REQUESTS];

            // pre-configure autoreset events/download slots
            for (int i = 0; i < MAX_TEXTURE_REQUESTS; i++)
            {
                resetEvents[i] = new AutoResetEvent(false);
                threadpoolSlots[i] = -1;
            }
        }

        public void StartDownload()
        {
            try
            {
                GridClient.Assets.OnImageReceived += new AssetManager.ImageReceivedCallback(Assets_OnImageReceived);

                MainThread = new Thread(new ThreadStart(DownloadTextureThread));
                MainThread.Start();
            }
            catch (Exception er)
            {
                Logger.DebugLog(er.Message);
            }
        }
        //public void StopDownload()
        //{ 
            
        //}

        private void DownloadTextureThread()
        {
            int reqNbr;

            while (true)
            {
                if (RequestQueue.Count > 0)
                {
                    reqNbr = -1;
                    // find available slot for reset event
                    for (int i = 0; i < threadpoolSlots.Length; i++)
                    {
                        if (threadpoolSlots[i] == -1)
                        {
                            threadpoolSlots[i] = 1;
                            reqNbr = i;
                            break;
                        }
                    }

                    if (reqNbr != -1)
                    {

                        UUID requestID;
                        lock (RequestQueue)
                            requestID = RequestQueue.Dequeue();

                        Logger.DebugLog(String.Format("Sending Worker thread new download request {0}", reqNbr));
                        ThreadPool.QueueUserWorkItem(new WaitCallback(textureRequestDoWork), new TaskInfo(requestID, reqNbr));

                        //gridClient.Assets.RequestImage(requestID, ImageType.Normal);

                        continue;
                    }
                }

                Thread.Sleep(1000);
            }

        }

        void textureRequestDoWork(Object threadContext)
         {
            TaskInfo ti = (TaskInfo)threadContext;

            lock (CurrentRequests)
            {
                if (CurrentRequests.ContainsKey(ti.RequestID))
                {
                    threadpoolSlots[ti.RequestNbr] = -1;
                    return;
                }
                else
                {
                    CurrentRequests.Add(ti.RequestID, ti.RequestNbr);
                }
            }

            Logger.DebugLog(String.Format("Worker {0} Requesting {1}", ti.RequestNbr, ti.RequestID));

            resetEvents[ti.RequestNbr].Reset();
           GridClient.Assets.RequestImage(ti.RequestID, ImageType.Normal);

            // don't release this worker slot until texture is downloaded or timeout occurs
            if (!resetEvents[ti.RequestNbr].WaitOne(300 * 1000, false))
            {
                // Timed out
                Logger.Log("Worker " + ti.RequestNbr + " Timeout waiting for Texture " + ti.RequestID + " to Download", Helpers.LogLevel.Warning);

                lock (CurrentRequests)
                    CurrentRequests.Remove(ti.RequestID);
            }

            // free up this download slot
            threadpoolSlots[ti.RequestNbr] = -1;
            ti = null;
        }
        
        private void Assets_OnImageReceived(ImageDownload image, AssetTexture asset)
        {
            if (image.Success)
            {
                //lock (CurruntTextures)
                //{
                //    if (!CurruntTextures.ContainsKey(image.ID))
                //    {
                //        CurruntTextures.Add(image.ID, image.AssetData);
                //    }
                //    else
                //    {
                //        CurruntTextures.Remove(image.ID);
                //        CurruntTextures.Add(image.ID, image.AssetData);
                //    }
                //}
                lock(objFileAccess)
                    if (File.Exists(Path.Combine(bmpFilePath, image.ID.ToString() + ".jpg")) == false)
                    {
                        //SaveTexture2Image(image);
                    }
            }
            
            if (onDownloadFinished != null)
            {
                onDownloadFinished(image.ID, image.Success);
            }
        }

        private void SaveTexture2Image(ImageDownload image)
        {
            ManagedImage managedimg;
            Image img;
            //byte[] bytes = GetTextureDataByTextureID(downLoadedTextureID);

            if (OpenJPEG.DecodeToImage(image.AssetData, out managedimg, out img))
            {
                Bitmap bitmap = new Bitmap(img);
                bitmap.Save(Path.Combine(bmpFilePath, image.ID.ToString() + ".jpg"), System.Drawing.Imaging.ImageFormat.Jpeg);

                bitmap.Dispose();
                bitmap = null;
            }

            img.Dispose();
            img = null;
            managedimg = null;
        }

        public ImageDownload RetireveTextureData(UUID textureID)
        {
            ImageDownload image =null;

            if (gridClient.Assets.Cache.HasImage(textureID))
            {
                image = gridClient.Assets.Cache.GetCachedImage(textureID);
            }
            else
            {
                lock (RequestQueue)
                {
                    // Make sure we aren't already downloading the texture
                    if (!RequestQueue.Contains(textureID)&& !CurrentRequests.ContainsKey(textureID))
                    {
                        RequestQueue.Enqueue(textureID);
                    }
                }
            }

            return image;
        }

        public void RequestTexture(UUID textureID)
        {
            //bool hasDownloaded = false;

            //lock (CurruntTextures)
            //{
            //    if (CurruntTextures.ContainsKey(textureID))
            //    {
            //        hasDownloaded = true;
            //    }
            //}
            //if (hasDownloaded)
            //    return;

            //if (gridClient.Assets.Cache.HasImage(textureID))
            //{
            //    // Add to rendering dictionary
            //    lock (CurruntTextures)
            //    {
            //        if (!CurruntTextures.ContainsKey(textureID))
            //        {
            //            CurruntTextures.Add(textureID, gridClient.Assets.Cache.GetCachedImage(textureID).AssetData);
            //        }
            //    }
            //}
            //else
            lock (objFileAccess)
            {
                if (File.Exists(Path.Combine(bmpFilePath, textureID.ToString() + ".jpg")) == false)
                {
                    if (gridClient.Assets.Cache.HasImage(textureID) == false)
                    {
                        lock (RequestQueue)
                        {
                            // Make sure we aren't already downloading the texture
                            if (!RequestQueue.Contains(textureID) && !CurrentRequests.ContainsKey(textureID))
                            {
                                RequestQueue.Enqueue(textureID);
                            }
                        }
                    }
                    else
                    {

                       // ImageDownload down = gridClient.Assets.Cache.GetCachedImage(textureID);
                       // SaveTexture2Image(down);

                    }
                }
            }
        }

        object objFileAccess = new object();

        public TextureDownloadFinished OnDownloadFinished
        {
            get
            {
                return onDownloadFinished;
            }
            set
            {
                onDownloadFinished = value;
            }
        }

     
    }

    class TaskInfo
    {
        public UUID RequestID;
        public int RequestNbr;


        public TaskInfo(UUID reqID, int reqNbr)
        {
            RequestID = reqID;
            RequestNbr = reqNbr;
        }
    }
}