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

namespace Work.Taobao
{
    public class TbHttpReauest
    {
        public string url = "";
        public string cookies = "";
        //Calls request functions sequentially.
        string responseText;
        public string MakeRequests()
        {
            HttpWebResponse response;            

            if (Request_trade_taobao_com(out response))
            {
                //Success, possibly use response.
                responseText = ReadResponse(response);

                response.Close();
            }
            else
            {
                //Failure, cannot use response.
            }
            return responseText;
        }

        //Returns the text contained in the response.  For example, the page HTML.  Only handles the most common HTTP encodings.
        private static string ReadResponse(HttpWebResponse response)
        {
            using (Stream responseStream = response.GetResponseStream())
            {
                Encoding enc = Encoding.UTF8;
                try
                {
                    var v = response.ResponseUri.Host;
                    if (v.Contains("trade.1688.com"))
                    {
                        enc = Encoding.Default;
                    }
                }
                catch (Exception)
                {

                }
              
                Stream streamToRead = responseStream;
                if (response.ContentEncoding.ToLower().Contains("gzip"))
                {
                    streamToRead = new GZipStream(streamToRead, CompressionMode.Decompress);
                }
                else if (response.ContentEncoding.ToLower().Contains("deflate"))
                {
                    streamToRead = new DeflateStream(streamToRead, CompressionMode.Decompress);
                }

                using (StreamReader streamReader = new StreamReader(streamToRead, enc))
                {
                    return streamReader.ReadToEnd();
                }
            }
        }

        /// <summary>
        /// Tries to request the URL: https://trade.taobao.com/trade/detail/trade_order_detail.htm?biz_order_id=1088944291427556938
        /// </summary>
        /// <param name="response">After the function has finished, will possibly contain the response to the request.</param>
        /// <returns>True if the request was successful; false otherwise.</returns>
        private bool Request_trade_taobao_com(out HttpWebResponse response)
        {
            response = null;

            try
            {
                //Create request to URL.
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

                //Set request headers.
                request.KeepAlive = true;
                request.Headers.Set(HttpRequestHeader.Pragma, "no-cache");
                request.Headers.Set(HttpRequestHeader.CacheControl, "no-cache");
                request.Headers.Add("Upgrade-Insecure-Requests", @"1");
                request.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36";
                request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8";
                request.Headers.Set(HttpRequestHeader.AcceptEncoding, "gzip, deflate, br");
                request.Headers.Set(HttpRequestHeader.AcceptLanguage, "en-US,en;q=0.9");
                request.Headers.Set(HttpRequestHeader.Cookie, cookies);

                //Get response to request.
                response = (HttpWebResponse)request.GetResponse();
            }
            catch (WebException e)
            {
                //ProtocolError indicates a valid HTTP response, but with a non-200 status code (e.g. 304 Not Modified, 404 Not Found)
                if (e.Status == WebExceptionStatus.ProtocolError) response = (HttpWebResponse)e.Response;
                else return false;
            }
            catch (Exception)
            {
                if (response != null) response.Close();
                return false;
            }

            return true;
        }
    }
}