using CRM.Core.Common.WebHelper;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Web;

namespace CRM.Core.Common.Ueditor
{
    /// <summary>
    /// UploadHandler 的摘要说明
    /// </summary>
    public class UploadHandler : Handler
    {
        public UploadConfig UploadConfig { get; private set; }
        public UploadResult Result { get; private set; }

        public UploadHandler(HttpContext context, UploadConfig config)
            : base(context)
        {
            this.UploadConfig = config;
            this.Result = new UploadResult() { State = UploadState.Unknown };
        }

        public override void Process()
        {
            byte[] uploadFileBytes = null;
            string uploadFileName = null;

            if (UploadConfig.Base64)
            {
                uploadFileName = UploadConfig.Base64Filename;
                uploadFileBytes = Convert.FromBase64String(Request[UploadConfig.UploadFieldName]);
            }
            else
            {
                var file = Request.Files[UploadConfig.UploadFieldName];
                uploadFileName = file.FileName;

                if (!CheckFileType(uploadFileName))
                {
                    Result.State = UploadState.TypeNotAllow;
                    WriteResult();
                    return;
                }
                if (!CheckFileSize(file.ContentLength))
                {
                    Result.State = UploadState.SizeLimitExceed;
                    WriteResult();
                    return;
                }
                int l = file.ContentLength;
                Stream fs = file.InputStream;
                try
                {
                    using (var client = new HttpClient())
                    {
                        //获取token
                        var fileserver = WX.CRM.Common.Utility.GetSettingByKey("fileserver"); // "http://192.168.11.81:5300";
                        var gettokenUrl = $"{fileserver}/api/Token";
                        var data = Utility.GetData(gettokenUrl, "key=7AC51A5F0DE9A13D5FC9960AD45CC8D5");
                        var token = $"Bearer {data}";

                        HttpWebRequest request = WebRequest.Create($"{fileserver}/Streaming/UploadLargeFile") as HttpWebRequest;
                        CookieContainer cookieContainer = new CookieContainer();
                        request.CookieContainer = cookieContainer;
                        request.AllowAutoRedirect = true;
                        request.Method = "POST";
                        string boundary = DateTime.Now.Ticks.ToString("X"); // 随机分隔线
                        request.ContentType = "multipart/form-data;charset=utf-8;boundary=" + boundary;
                        byte[] itemBoundaryBytes = Encoding.UTF8.GetBytes("\r\n--" + boundary + "\r\n");
                        byte[] endBoundaryBytes = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n");
                        request.Headers.Add("Authorization", token);
                        string fileName = uploadFileName;

                        //请求头部信息
                        StringBuilder sbHeader = new StringBuilder(string.Format("Content-Disposition:form-data;name=\"file\";filename=\"{0}\"\r\nContent-Type:application/octet-stream\r\n\r\n", fileName));
                        byte[] postHeaderBytes = Encoding.UTF8.GetBytes(sbHeader.ToString());

                        byte[] bArr = new byte[fs.Length];
                        fs.Read(bArr, 0, bArr.Length);
                        fs.Close();

                        Stream postStream = request.GetRequestStream();
                        postStream.Write(itemBoundaryBytes, 0, itemBoundaryBytes.Length);
                        postStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);
                        postStream.Write(bArr, 0, bArr.Length);
                        postStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);
                        postStream.Close();

                        //发送请求并获取相应回应数据
                        HttpWebResponse response = request.GetResponse() as HttpWebResponse;
                        //直到request.GetResponse()程序才开始向目标网页发送Post请求
                        Stream instream = response.GetResponseStream();
                        StreamReader sr = new StreamReader(instream, Encoding.UTF8);
                        //返回结果网页（html）代码
                        string content = sr.ReadToEnd();
                        var res = JsonHelper.FromJson<UpLoadResult>(content);
                        if (res.success == true)
                        {
                            Result.Url = res.url;
                            Result.State = UploadState.Success;
                        }
                        else
                        {
                            Result.State = UploadState.FileAccessError;
                        }
                    }
                }
                catch (Exception ex)
                {
                    Result.State = UploadState.FileAccessError;
                    Result.ErrorMessage = ex.Message;
                }
                finally
                {
                    WriteResult();
                }
            }
        }

        private void WriteResult()
        {
            this.WriteJson(new
            {
                state = GetStateMessage(Result.State),
                url = Result.Url,
                title = Result.OriginFileName,
                original = Result.OriginFileName,
                error = Result.ErrorMessage
            });
        }

        private string GetStateMessage(UploadState state)
        {
            switch (state)
            {
                case UploadState.Success:
                    return "SUCCESS";

                case UploadState.FileAccessError:
                    return "文件访问出错，请检查写入权限";

                case UploadState.SizeLimitExceed:
                    return "文件大小超出服务器限制";

                case UploadState.TypeNotAllow:
                    return "不允许的文件格式";

                case UploadState.NetworkError:
                    return "网络错误";
            }
            return "未知错误";
        }

        private bool CheckFileType(string filename)
        {
            var fileExtension = Path.GetExtension(filename).ToLower();
            return UploadConfig.AllowExtensions.Select(x => x.ToLower()).Contains(fileExtension);
        }

        private bool CheckFileSize(int size)
        {
            return size < UploadConfig.SizeLimit;
        }
    }

    public class UploadConfig
    {
        /// <summary>
        /// 文件命名规则
        /// </summary>
        public string PathFormat { get; set; }

        /// <summary>
        /// 上传表单域名称
        /// </summary>
        public string UploadFieldName { get; set; }

        /// <summary>
        /// 上传大小限制
        /// </summary>
        public int SizeLimit { get; set; }

        /// <summary>
        /// 上传允许的文件格式
        /// </summary>
        public string[] AllowExtensions { get; set; }

        /// <summary>
        /// 文件是否以 Base64 的形式上传
        /// </summary>
        public bool Base64 { get; set; }

        /// <summary>
        /// Base64 字符串所表示的文件名
        /// </summary>
        public string Base64Filename { get; set; }
    }

    public class UploadResult
    {
        public UploadState State { get; set; }
        public string Url { get; set; }
        public string OriginFileName { get; set; }

        public string ErrorMessage { get; set; }
    }

    public enum UploadState
    {
        Success = 0,
        SizeLimitExceed = -1,
        TypeNotAllow = -2,
        FileAccessError = -3,
        NetworkError = -4,
        Unknown = 1,
    }

    public class UpLoadResult
    {
        public bool? isEnd { get; set; }
        public bool? success { get; set; }
        public string url { get; set; }
    }
}