using System;

using System.Configuration;

using System.Drawing;

using System.Drawing.Imaging;

using System.Globalization;

using System.IO;

using System.Text.RegularExpressions;

using System.Web;

using EW.EWorkpal.Core.Common.MongoProvider.MongoGridFSRepository.Models;

using EW.EWorkpal.Core.System;

using EW.EWorkpal.Services.FileManagerService.ImageProvider;

namespace EW.EWorkpal.Modules.Picture

{

    public class PictureWebHandler : ServiceBase, IHttpHandler

    {

        public void ProcessRequest(HttpContext context)

        {

            HttpResponse response = context.Response;

            HttpRequest request = context.Request;

            #region 客户端缓存

            int clientCacheTime;   //客户端缓存时间（秒）

            string clientCacheSecond = GetAppSetting("ClientCacheSecond", true);

            if (!int.TryParse(clientCacheSecond, out clientCacheTime))

                clientCacheTime = ;

            string clearHeadImage = request.Headers["Clear-HeadImage"];

            if (!string.IsNullOrEmpty(clearHeadImage))

            {

                ClearClientCaching(context.Response);

                return;

            }

            string headerModified = request.Headers["If-Modified-Since"];

            if (headerModified != null)

            {

                long nowTicks = DateTime.Now.Ticks;

                long modifiedTick = DateTime.Parse(request.Headers["If-Modified-Since"]).Ticks;

                long ticks = nowTicks - modifiedTick;

                if (TimeSpan.FromTicks(ticks).Seconds < clientCacheTime)

                {

                    response.StatusCode = ;

                    // 这种方式会产生“此操作要求使用 IIS 集成管线模式。 ”的异常

                    //Response.Headers.Add("Content-Encoding", "gzip");

                    // Response.Headers.Add 和 Response.AddHeader 但是在MSDN中明确写出，这些都是为了兼容ASP，在.NET 3.5要求使用下面这种方式。

                    //这种方式不会出现异常

                    response.AppendHeader("Content-Encoding", "gzip");

                    response.StatusDescription = "Not Madified";

                    response.End();

                    return;

                }

            }

            #endregion

            string regex = GetAppSetting("UrlRegex");

            string sourceRegex = GetAppSetting("SourceUrlRegex");

            string headRegex = GetAppSetting("HeadImageUrlRegex");

            string comLogoRegex = GetAppSetting("ComLogoUrlRegex");

            string url = request.Url.AbsoluteUri;

            int regexIndex;

            if (Regex.IsMatch(url, headRegex, RegexOptions.IgnoreCase))

                regexIndex = ;

            else if (Regex.IsMatch(url, comLogoRegex, RegexOptions.IgnoreCase))

                regexIndex = ;

            else if (Regex.IsMatch(url, regex, RegexOptions.IgnoreCase))

                regexIndex = ;

            else if (Regex.IsMatch(url, sourceRegex, RegexOptions.IgnoreCase))

                regexIndex = ;

            else

                regexIndex = ;

            if (regexIndex == )

            {

                Error404(response);

                return;

            }

            #region 用户头像

            if (regexIndex == )

            {

                var regResult = Regex.Match(url, @"\d+/\d+").Value;

                var str = regResult.Split('/');

                if (str.Length < )

                {

                    Error404(response);

                    return;

                }

                int id, size;

                if (!int.TryParse(str[], out id))

                {

                    Error404(response);

                    return;

                }

                if (!int.TryParse(str[], out size))

                {

                    Error404(response);

                    return;

                }

                if (size == )

                {

                    size = ;

                }

                else if (size == )

                {

                    size = ;

                }

                else

                {

                    size = ;

                }

                var srcPicBytes = GetService<IImageService>().GetHeadImage(id);

                if (srcPicBytes != null)

                {

                    Stream stream = GetHighHeadImage(srcPicBytes, size);

                    long dataToRead = stream.Length;

                    byte[] bytes = ((MemoryStream)stream).GetBuffer();

                    response.Buffer = true;

                    response.ContentType = "image/jpeg";

                    while (dataToRead > )

                    {

                        if (response.IsClientConnected)

                        {

                            int length = bytes.Length;

                            byte[] buffer = bytes;

                            response.OutputStream.Write(buffer, , length);

                            response.Flush();

                            dataToRead = dataToRead - length;

                        }

                        else

                        {

                            dataToRead = -;

                        }

                    }

                    SetClientCaching(response, DateTime.Now, clientCacheTime);

                }

                else

                {

                    //if (requesthost != picturehost)//盗链，返回提示图片

                    ////{

                    ////    context.Response.WriteFile("/Img/linknotice/ImageForbiden.jpg");

                    ////}

                    context.Response.ClearContent();

                    context.Response.WriteFile("/img/headimg/noavatar_" + size + "_" + size + ".jpg");

                    context.Response.ContentType = "image/jpeg";

                    context.Response.End();

                    return;

                }

//                context.Response.ClearContent();

//                context.Response.ContentType = "image/jpeg";

                context.Response.End();

                return;

            }

            #endregion

            #region 企业Logo

            if (regexIndex == )

            {

                var regResult = Regex.Match(url, @"ent/\d+").Value;

                var str = regResult.Split('/');

                if (str.Length < )

                {

                    Error404(response);

                    return;

                }

                int size;

                if (!int.TryParse(str[], out size))

                {

                    Error404(response);

                    return;

                }

                if (size == )

                {

                    size = ;

                }

                else if (size == )

                {

                    size = ;

                }

                else

                {

                    size = ;

                }

                string fileName = regexIndex ==  ? Regex.Match(url, regex, RegexOptions.IgnoreCase).Groups[].Value : Regex.Match(url, sourceRegex, RegexOptions.IgnoreCase).Groups[].Value;

                MongoFileInfo options;

                var srcPicBytes = GetService<IImageService>().Get(fileName, out options);

                if (srcPicBytes != null)

                {

                    Stream stream = GetHighHeadImage(srcPicBytes, size);

                    long dataToRead = stream.Length;

                    byte[] bytes = ((MemoryStream)stream).GetBuffer();

                    response.Buffer = true;

                    response.ContentType = "image/jpeg";

                    while (dataToRead > )

                    {

                        if (response.IsClientConnected)

                        {

                            int length = bytes.Length;

                            byte[] buffer = bytes;

                            response.OutputStream.Write(buffer, , length);

                            response.Flush();

                            dataToRead = dataToRead - length;

                        }

                        else

                        {

                            dataToRead = -;

                        }

                    }

                    SetClientCaching(response, DateTime.Now, clientCacheTime);

                }

                else

                {

                    context.Response.ClearContent();

                    context.Response.WriteFile(string.Format("/img/comlogo/{0}x{0}.jpg",size));

                    context.Response.ContentType = "image/jpeg";

                    context.Response.End();

                    return;

                }

//                context.Response.ClearContent();

//                context.Response.ContentType = "image/jpeg";

                context.Response.End();

                return;

            }

            #endregion

            #region 读取原图

            if (regexIndex ==  || regexIndex == )

            {

                string fileName = regexIndex ==  ? Regex.Match(url, regex, RegexOptions.IgnoreCase).Groups[].Value : Regex.Match(url, sourceRegex, RegexOptions.IgnoreCase).Groups[].Value;

                MongoFileInfo options;

                var srcPicBytes = GetService<IImageService>().Get(fileName, out options);

                if (srcPicBytes == null || srcPicBytes.Length <= )

                {

                    Error404(response);

                    return;

                }

                var srcPicStream = new MemoryStream(srcPicBytes);

                Image srcImage = Image.FromStream(srcPicStream);

                Image destImage = null;

                if (regexIndex == )

                {

                    int destWidth = int.Parse(Regex.Match(url, regex, RegexOptions.IgnoreCase).Groups[].Value);

                    int destHeight = int.Parse(Regex.Match(url, regex, RegexOptions.IgnoreCase).Groups[].Value);

                    string zoomType = Regex.Match(url, regex, RegexOptions.IgnoreCase).Groups[].Value;

                    bool zoomCut = zoomType.ToUpper() == "-C";

                    bool zoomFit = zoomType.ToUpper() == "-F";

                    //缩略

                    destImage = ZoomPic.Zoom(srcImage,

                                             new ZoomParam

                                             {

                                                 Width = destWidth,

                                                 Height = destHeight,

                                                 Type =

                                                     zoomCut

                                                         ? EnumZoomType.Cut

                                                         : zoomFit ? EnumZoomType.Fit : EnumZoomType.Cut

                                             });

                }

                else

                {

                    //返回原图

                    destImage = srcImage;

                }

                #region 输出

                Stream stream = new MemoryStream();

                try

                {

                    if (destImage != null) destImage.Save(stream, ImageFormat.Jpeg);

                    long dataToRead = stream.Length;

                    byte[] bytes = ((MemoryStream)stream).GetBuffer();

                    SetClientCaching(response, DateTime.Now, clientCacheTime);

                    response.Buffer = true;

                    response.ContentType = "image/jpeg";

                    while (dataToRead > )

                    {

                        if (response.IsClientConnected)

                        {

                            int length = bytes.Length;

                            byte[] buffer = bytes;

                            response.OutputStream.Write(buffer, , length);

                            response.Flush();

                            dataToRead = dataToRead - length;

                        }

                        else

                        {

                            dataToRead = -;

                        }

                    }

                }

                catch (Exception e)

                {

                    ClearClientCaching(response);

                    throw new Exception(e.Message);

                }

                finally

                {

                    srcImage.Dispose();

                    srcPicStream.Dispose();

                    if (destImage != null) destImage.Dispose();

                    stream.Dispose();

                }

                #endregion

            }

            #endregion

        }

        #region private methods

        private static string GetAppSetting(string key, bool allowNull = false)

        {

            if (ConfigurationManager.AppSettings[key] == null)

            {

                if (allowNull)

                    return "";

                throw new ConfigurationErrorsException(string.Format("找不到appSettings配置，配置项{0}", key));

            }

            return ConfigurationManager.AppSettings[key];

        }

        private void SetClientCaching(HttpResponse response, DateTime lastModified, int clientCacheTime)

        {

            response.ContentType = "image/jpeg";

            //将ETag Http标头设置为制定字符串

            response.Cache.SetETag(lastModified.Ticks.ToString(CultureInfo.InvariantCulture));

            //将Last_Modified Http标头设置为提供的System.DateTime值

            response.Cache.SetLastModified(lastModified);

            //将Cache-Control 标头设置为System.Web.HttpCacheability值之一

            response.Cache.SetCacheability(HttpCacheability.Public);

            //基于制定的时间跨度设置Cache-Control: max-age HTTP标头

            response.Cache.SetMaxAge(new TimeSpan(, , , clientCacheTime));

            //将缓存过期从绝对时间设置为可调时间

            response.Cache.SetSlidingExpiration(true);

        }

        private void ClearClientCaching(HttpResponse response)

        {

            response.Cache.SetExpires(DateTime.Now);

        }

        private MemoryStream GetHeadImage(Byte[] file, int size)

        {

            size = size >  ?  : size;

            MemoryStream stream = new MemoryStream(file);

            Bitmap bmp = new Bitmap(Image.FromStream(stream));

            Image image = bmp.GetThumbnailImage(size, size, null, IntPtr.Zero);

            MemoryStream ms = new MemoryStream();

            image.Save(ms, ImageFormat.Jpeg);

            return ms;

        }

        private MemoryStream GetHighHeadImage(Byte[] file, int size)

        {

            MemoryStream ms = new MemoryStream();

            Image originalImage = Image.FromStream(new MemoryStream(file));

            //新建一个bmp图片

            Image bitmap = new Bitmap(size, size);

            //新建一个画板

            Graphics g = Graphics.FromImage(bitmap);

            //设置高质量插值法

            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

            //设置高质量,低速度呈现平滑程度

            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

            //清空画布并以透明背景色填充

            g.Clear(Color.Transparent);

            //在指定位置并且按指定大小绘制原图片的指定部分

            g.DrawImage(originalImage, new Rectangle(, , size, size), new Rectangle(, , originalImage.Width, originalImage.Height), GraphicsUnit.Pixel);

            try

            {

                //以jpg格式保存缩略图

                bitmap.Save(ms, ImageFormat.Png);

            }

            catch (Exception e)

            {

                throw e;

            }

            finally

            {

                originalImage.Dispose();

                bitmap.Dispose();

                g.Dispose();

            }

            return ms;

        }

        #endregion

        /// <summary>

        /// 返回404

        /// </summary>

        private static void Error404(HttpResponse response)

        {

            response.StatusCode = ;

            response.Flush();

            response.End();

        }

        public bool IsReusable { get { return false; } }

    }

}