// Copyright (C) 2016 by David Jeske, Barend Erasmus and donated to the public domain

using SimpleHttpServer;

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

using Sog;

namespace SimpleHttpServer
{

    public class HttpServer
    {
        #region Fields

        private int Port;
        private TcpListener Listener;
        private HttpProcessor Processor;
        private bool IsActive = true;
        private uint httpCtxSeq = 1;
        #endregion

        //http处理线程结束钱等待时间，有些http response依赖其他服务器返回，没法立即处理，防止垃圾回收造成网络断线影响，增加这个时间
        public int ProcessorThreadEndWaitTimeMs = 5000;
       

        #region Public Methods
        public HttpServer(int port, List<Route> routes)
        {
            this.Port = port;
            this.Processor = new HttpProcessor();

            foreach (var route in routes)
            {
                this.Processor.AddRoute(route);
            }
        }
		
        
        public void Listen()
        {
            this.Listener = new TcpListener(IPAddress.Any, this.Port);
            this.Listener.Start();

            while (this.IsActive)
            {
                TcpClient s = this.Listener.AcceptTcpClientAsync().Result;
                //保证response的时候立即发送,usdk那边总是会出现callback我们支付服务器没有收到response就tcp reset了
                s.NoDelay = true;
                var httpCtx = new HttpContext(s) { id = httpCtxSeq++ };

                //Task中使用sleep是不正确的用法，Task底层使用的是线程池，并不会由于调用Sleep把线程让出来,使用sleep导致能够执行的Task数量是受线程池大小限制 zouwei 2023/5/25
                //new Thread性能在windows下非常的低，linux高些，后期业务量大了，可以考虑重构这个网络代码，比如用Sog.SessionListener代替,或者简单的用select模型都比这个靠谱，或者使用await异步
                try
                {
                    var t = new Thread(() => {                       
                        this.Processor.HandleClient(httpCtx);
                        var beginTime = DateTime.Now;

                        // 之前发现微软云经常出现tcp连接被RST导致http response没有发送成功, 看看是否线程内部异常
                        try
                        {
                            while (true)
                            {
                                if ((DateTime.Now - beginTime).TotalMilliseconds >= ProcessorThreadEndWaitTimeMs)
                                {
                                    if (httpCtx != null && httpCtx.httpRequest != null)
                                    {
                                        TraceLog.Error("SyncHttpServerService request method {0} url {1} timeout!", httpCtx.httpRequest.Method, httpCtx.httpRequest.Url);
                                    }
                                    else
                                    {
                                        TraceLog.Error("SyncHttpServerService request timeout!");
                                    }
                                    break;
                                }
                                Thread.Sleep(10);
                                if (httpCtx.isSendRes)
                                {
                                    Thread.Sleep(200);
                                    break;
                                }
                            }
                            //关闭一下，usdk那边总是会出现callback我们支付服务器没有收到response就tcp reset了
                            httpCtx.client.Close();
                        }
                        catch (Exception e)
                        {
                            TraceLog.Exception(e);
                            if (e.InnerException != null)
                            {
                                TraceLog.Exception(e.InnerException);
                            }
                        }
                        
                    }, 1024 * 1024);

                    t.IsBackground = true;
                    t.Start();
                }
                catch (Exception ex)
                {
                    TraceLog.Exception(ex);
                }
            }
        }

        // this formats the HTTP response...
        public static void SendResponse(HttpContext httpCtx)
        {
            try
            {
                HttpResponse response = httpCtx.httpResponse;

                // default to text/html content type
                if (!response.Headers.ContainsKey("Content-Type"))
                {
                    response.Headers["Content-Type"] = "text/html";
                }

                response.Headers["Content-Length"] = response.Content.Length.ToString();

                var stream = httpCtx.client.GetStream();
                // Keep-Alive在1.0中默认关闭
                Write(stream, string.Format("HTTP/1.0 {0} {1}\r\n", response.StatusCode, response.ReasonPhrase));
                Write(stream, string.Join("\r\n", response.Headers.Select(x => string.Format("{0}: {1}", x.Key, x.Value))));
                Write(stream, "\r\n\r\n");

                if (response.Content == null)
                {
                    response.Content = new byte[] { };
                }

                stream.Write(response.Content, 0, response.Content.Length);
            }
            catch (Exception e)
            {
                TraceLog.Exception(e);
            }
            finally 
            {
                httpCtx.isSendRes = true;
            }
        }

        private static void Write(Stream stream, string text)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(text);
            stream.Write(bytes, 0, bytes.Length);
        }

        #endregion

    }
}