using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading.Tasks;

namespace learun.wechat
{
	/// <summary>
	/// 版 本 EasyCode EC管理后台
	/// Copyright (c) 2019-present EC管理有限公司
	/// 创建人：tobin
	/// 日 期：2019.11.06
	/// 描 述：http请求
	/// </summary>
	public class HttpHelper
	{
		/// <summary>
		/// 是否是调试
		/// </summary>
		public bool Debug { get; set; }

		/// <summary>
		/// cookies
		/// </summary>
		public CookieCollection Cookies
		{
			get { return _cookies; }
		}

		/// <summary>
		/// 清空cookies
		/// </summary>
		public void ClearCookies()
		{
			_cookies = new CookieCollection();
		}

		private CookieCollection _cookies = new CookieCollection();

		private static readonly string DefaultUserAgent = "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; WOW64; Trident/6.0)";

		/// <summary>
		/// 创建GET方式的HTTP请求
		/// </summary>
		/// <param name="url">请求的URL</param>
		/// <param name="timeout">请求的超时时间</param>
		/// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
		/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
		/// <param name="Referer">重定向</param>
		/// <param name="headers">头部信息</param>
		/// <returns></returns>
		public async Task<HttpWebResponse> CreateGetHttpResponse(string url, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			if (Debug)
			{
				Console.Write("Start Get Url:{0}    ", url);
			}

			if (string.IsNullOrEmpty(url))
			{
				throw new ArgumentNullException("url");
			}

			HttpWebRequest request;
			if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
			{
				ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
				request = WebRequest.Create(url) as HttpWebRequest;
				request.ProtocolVersion = HttpVersion.Version10;
			}
			else
			{
				request = WebRequest.Create(url) as HttpWebRequest;
			}

			request.Method = "GET";
			request.Headers["Pragma"] = "no-cache";
			request.Accept = "text/html, application/xhtml+xml, */*";
			request.Headers["Accept-Language"] = "en-US,en;q=0.5";
			request.ContentType = "application/x-www-form-urlencoded";
			request.UserAgent = DefaultUserAgent;
			request.Referer = Referer;

			if (headers != null)
			{
				foreach (var header in headers)
				{
					request.Headers.Add(header.Key, header.Value);
				}
			}

			if (!string.IsNullOrEmpty(userAgent))
			{
				request.UserAgent = userAgent;
			}
			if (timeout.HasValue)
			{
				request.Timeout = timeout.Value * 1000;
			}
			if (cookies != null)
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(cookies);
			}
			else
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(Cookies);
			}
			var v = await request.GetResponseAsync() as HttpWebResponse;

			Cookies.Add(request.CookieContainer.GetCookies(new Uri("http://" + new Uri(url).Host)));
			Cookies.Add(request.CookieContainer.GetCookies(new Uri("https://" + new Uri(url).Host)));
			Cookies.Add(v.Cookies);

			if (Debug)
			{
				Console.WriteLine("OK");
			}

			return v;
		}

		/// <summary>
		/// 创建POST方式的HTTP请求
		/// </summary>
		/// <param name="url">请求的URL</param>
		/// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
		/// <param name="timeout">请求的超时时间</param>
		/// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
		/// <param name="requestEncoding">发送HTTP请求时所用的编码</param>
		/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
		/// <param name="Referer">重定向</param>
		/// <param name="headers">头部信息</param>
		/// <returns></returns>
		public async Task<HttpWebResponse> CreatePostHttpResponse(string url, IDictionary<string, string> parameters, Encoding requestEncoding, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			if (Debug)
			{
				Console.Write("Start Post Url:{0}  ", url);

				foreach (KeyValuePair<string, string> keyValuePair in parameters)
				{
					Console.Write(",{0}:{1}", keyValuePair.Key, keyValuePair.Value);
				}
			}

			if (string.IsNullOrEmpty(url))
			{
				throw new ArgumentNullException("url");
			}
			if (requestEncoding == null)
			{
				throw new ArgumentNullException("requestEncoding");
			}
			HttpWebRequest request = null;
			//如果是发送HTTPS请求
			if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
			{
				ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
				request = WebRequest.Create(url) as HttpWebRequest;
				request.ProtocolVersion = HttpVersion.Version10;
			}
			else
			{
				request = WebRequest.Create(url) as HttpWebRequest;
			}
			request.Method = "POST";
			request.Accept = "text/html, application/xhtml+xml, application/json, text/javascript, */*; q=0.01";
			request.Referer = Referer;
			request.Headers["Accept-Language"] = "en-US,en;q=0.5";
			request.UserAgent = DefaultUserAgent;
			request.ContentType = "application/x-www-form-urlencoded";
			request.Headers["Pragma"] = "no-cache";

			if (headers != null)
			{
				foreach (var header in headers)
				{
					request.Headers.Add(header.Key, header.Value);
				}
			}

			if (cookies != null)
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(cookies);
			}
			else
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(Cookies);
			}

			if (!string.IsNullOrEmpty(userAgent))
			{
				request.UserAgent = userAgent;
			}
			else
			{
				request.UserAgent = DefaultUserAgent;
			}

			if (timeout.HasValue)
			{
				request.Timeout = timeout.Value * 1000;
			}

			request.Expect = string.Empty;

			//如果需要POST数据
			if (!(parameters == null || parameters.Count == 0))
			{
				var buffer = CraeteParameter(parameters);
				byte[] data = requestEncoding.GetBytes(buffer.ToString());
				Stream stream = request.GetRequestStream();
				stream.Write(data, 0, data.Length);
				stream.Close();
				stream.Dispose();
			}
			var v = await request.GetResponseAsync() as HttpWebResponse;

			Cookies.Add(request.CookieContainer.GetCookies(new Uri("http://" + new Uri(url).Host)));
			Cookies.Add(request.CookieContainer.GetCookies(new Uri("https://" + new Uri(url).Host)));

			Cookies.Add(v.Cookies);

			if (Debug)
			{
				Console.WriteLine("OK");
			}

			return v;
		}

		/// <summary>
		/// 创建POST方式的HTTP请求
		/// </summary>
		/// <param name="url">请求的URL</param>
		/// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
		/// <param name="timeout">请求的超时时间</param>
		/// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
		/// <param name="requestEncoding">发送HTTP请求时所用的编码</param>
		/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
		/// <param name="Referer">重定向</param>
		/// <param name="headers">头部信息</param>
		/// <returns></returns>
		public async Task<HttpWebResponse> CreatePostHttpResponse(string url, string parameters, Encoding requestEncoding, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			if (Debug)
			{
				Console.Write("Start Post Url:{0} ,parameters:{1}  ", url, parameters);
			}

			if (string.IsNullOrEmpty(url))
			{
				throw new ArgumentNullException("url");
			}
			if (requestEncoding == null)
			{
				throw new ArgumentNullException("requestEncoding");
			}
			HttpWebRequest request = null;
			//如果是发送HTTPS请求
			if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
			{
				ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
				request = WebRequest.Create(url) as HttpWebRequest;
				request.ProtocolVersion = HttpVersion.Version10;
			}
			else
			{
				request = WebRequest.Create(url) as HttpWebRequest;
			}

			request.Method = "POST";
			request.Headers.Add("Accept-Language", "zh-CN,en-GB;q=0.5");
			request.Method = "POST";
			request.Accept = "text/html, application/xhtml+xml, */*";
			request.Referer = Referer;
			request.Headers["Accept-Language"] = "en-US,en;q=0.5";
			request.UserAgent = DefaultUserAgent;
			request.ContentType = "application/x-www-form-urlencoded";
			request.Headers["Pragma"] = "no-cache";

			if (cookies != null)
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(cookies);
			}
			else
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(Cookies);
			}

			if (headers != null)
			{
				foreach (var header in headers)
				{
					request.Headers.Add(header.Key, header.Value);
				}
			}

			if (!string.IsNullOrEmpty(userAgent))
			{
				request.UserAgent = userAgent;
			}
			else
			{
				request.UserAgent = DefaultUserAgent;
			}

			if (timeout.HasValue)
			{
				request.Timeout = timeout.Value * 1000;
			}

			request.Expect = string.Empty;

			//如果需要POST数据
			if (!string.IsNullOrEmpty(parameters))
			{
				byte[] data = requestEncoding.GetBytes(parameters);
				Stream stream = request.GetRequestStream();
				stream.Write(data, 0, data.Length);
				stream.Close();
				stream.Dispose();
			}

			var v = await request.GetResponseAsync() as HttpWebResponse;

			Cookies.Add(request.CookieContainer.GetCookies(new Uri("http://" + new Uri(url).Host)));
			Cookies.Add(request.CookieContainer.GetCookies(new Uri("https://" + new Uri(url).Host)));
			Cookies.Add(v.Cookies);

			if (Debug)
			{
				Console.WriteLine("OK");
			}

			return v;
		}

		/// <summary>
		/// 创建POST方式的HTTP请求
		/// </summary>
		/// <param name="url">请求的URL</param>
		/// <param name="filePath">文件路径</param>
		/// <param name="timeout">请求的超时时间</param>
		/// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
		/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
		/// <param name="Referer">重定向</param>
		/// <param name="headers">头部信息</param>
		/// <returns></returns>
		public async Task<HttpWebResponse> CreatePostFileHttpResponse(string url, string filePath, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			if (Debug)
			{
				Console.Write("Start Post Url:{0}  ", url);
			}

			if (string.IsNullOrEmpty(url))
			{
				throw new ArgumentNullException("url");
			}

			HttpWebRequest request = null;
			//如果是发送HTTPS请求
			if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
			{
				ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
				request = WebRequest.Create(url) as HttpWebRequest;
				request.ProtocolVersion = HttpVersion.Version10;
			}
			else
			{
				request = WebRequest.Create(url) as HttpWebRequest;
			}
			request.Method = "POST";
			request.Accept = "text/html, application/xhtml+xml, application/json, text/javascript, */*; q=0.01";
			request.Referer = Referer;
			request.Headers["Accept-Language"] = "en-US,en;q=0.5";
			request.UserAgent = DefaultUserAgent;
			request.ContentType = "application/x-www-form-urlencoded";
			request.Headers["Pragma"] = "no-cache";

			if (headers != null)
			{
				foreach (var header in headers)
				{
					request.Headers.Add(header.Key, header.Value);
				}
			}

			if (cookies != null)
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(cookies);
			}
			else
			{
				request.CookieContainer = new CookieContainer();
				request.CookieContainer.Add(Cookies);
			}

			if (!string.IsNullOrEmpty(userAgent))
			{
				request.UserAgent = userAgent;
			}
			else
			{
				request.UserAgent = DefaultUserAgent;
			}

			if (timeout.HasValue)
			{
				request.Timeout = timeout.Value * 1000;
			}

			request.Expect = string.Empty;

			//如果需要POST数据
			if (!string.IsNullOrEmpty(filePath))
			{
				using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
				{
					BinaryReader r = new BinaryReader(fs);

					//时间戳
					string strBoundary = "----------" + DateTime.Now.Ticks.ToString("x");
					byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + strBoundary + "\r\n");

					//请求头部信息
					StringBuilder sb = new StringBuilder();
					sb.Append("--");
					sb.Append(strBoundary);
					sb.Append("\r\n");
					sb.Append("Content-Disposition: form-data; name=\"");
					sb.Append("file");
					sb.Append("\"; filename=\"");
					sb.Append(fs.Name);
					sb.Append("\"");
					sb.Append("\r\n");
					sb.Append("Content-Type: ");
					sb.Append("application/octet-stream");
					sb.Append("\r\n");
					sb.Append("\r\n");
					string strPostHeader = sb.ToString();
					byte[] postHeaderBytes = Encoding.UTF8.GetBytes(strPostHeader);

					request.ContentType = "multipart/form-data; boundary=" + strBoundary;
					long length = fs.Length + postHeaderBytes.Length + boundaryBytes.Length;

					request.ContentLength = length;

					//开始上传时间
					DateTime startTime = DateTime.Now;

					byte[] filecontent = new byte[fs.Length];

					fs.Read(filecontent, 0, filecontent.Length);

					using (Stream stream = request.GetRequestStream())
					{
						//发送请求头部消息
						stream.Write(postHeaderBytes, 0, postHeaderBytes.Length);

						stream.Write(filecontent, 0, filecontent.Length);

						//添加尾部的时间戳
						stream.Write(boundaryBytes, 0, boundaryBytes.Length);
					}
				}
			}
			var v = await request.GetResponseAsync() as HttpWebResponse;

			Cookies.Add(request.CookieContainer.GetCookies(new Uri("http://" + new Uri(url).Host)));
			Cookies.Add(request.CookieContainer.GetCookies(new Uri("https://" + new Uri(url).Host)));

			Cookies.Add(v.Cookies);

			if (Debug)
			{
				Console.WriteLine("OK");
			}

			return v;
		}

		/// <summary>
		/// 创建参数
		/// </summary>
		/// <param name="parameters">参数</param>
		/// <returns></returns>
		public static string CraeteParameter(IDictionary<string, string> parameters)
		{
			StringBuilder buffer = new StringBuilder();
			foreach (string key in parameters.Keys)
			{
				buffer.AppendFormat("&{0}={1}", key, parameters[key]);
			}
			return buffer.ToString().TrimStart('&');
		}

		private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
		{
			return true; //总是接受
		}

		/// <summary>
		/// post请求
		/// </summary>
		/// <param name="url">请求的URL</param>
		/// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
		/// <param name="requestEncoding">发送HTTP请求时所用的编码</param>
		/// <param name="responseEncoding">发送HTTP响应时所用的编码</param>
		/// <param name="timeout">请求的超时时间</param>
		/// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
		/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
		/// <param name="Referer">重定向</param>
		/// <param name="headers">头部信息</param>
		/// <returns></returns>
		public async Task<string> Post(string url, IDictionary<string, string> parameters, Encoding requestEncoding, Encoding responseEncoding, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			HttpWebResponse response = await CreatePostHttpResponse(url, parameters, requestEncoding, timeout, userAgent, cookies, Referer, headers);

			try
			{
				StreamReader reader = new StreamReader(response.GetResponseStream(), responseEncoding);
				string res = reader.ReadToEnd();
				reader.Close();
				reader.Dispose();

				return res;
			}
			catch (Exception)
			{
				return null;
			}
		}

		/// <summary>
		/// post请求
		/// </summary>
		/// <param name="url"></param>
		/// <param name="parameters"></param>
		/// <param name="requestEncoding"></param>
		/// <param name="responseEncoding"></param>
		/// <param name="timeout"></param>
		/// <param name="userAgent"></param>
		/// <param name="cookies"></param>
		/// <param name="Referer"></param>
		/// <param name="headers"></param>
		/// <returns></returns>
		public async Task<string> Post(string url, string parameters, Encoding requestEncoding, Encoding responseEncoding, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			HttpWebResponse response = await CreatePostHttpResponse(url, parameters, requestEncoding, timeout, userAgent, cookies, Referer, headers);

			try
			{
				StreamReader reader = new StreamReader(response.GetResponseStream(), responseEncoding);
				string res = reader.ReadToEnd();
				reader.Close();
				reader.Dispose();
				return res;
			}
			catch (Exception)
			{
				return null;
			}
		}

		/// <summary>
		/// post请求
		/// </summary>
		/// <param name="url"></param>
		/// <param name="filePath"></param>
		/// <param name="responseEncoding"></param>
		/// <param name="timeout"></param>
		/// <param name="userAgent"></param>
		/// <param name="cookies"></param>
		/// <param name="Referer"></param>
		/// <param name="headers"></param>
		/// <returns></returns>
		public async Task<string> PostFile(string url, string filePath, Encoding responseEncoding,
			int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "",
			Dictionary<string, string> headers = null)
		{
			HttpWebResponse response = await CreatePostFileHttpResponse(url, filePath, timeout, userAgent, cookies, Referer,
				headers);

			try
			{
				StreamReader reader = new StreamReader(response.GetResponseStream(), responseEncoding);
				string res = reader.ReadToEnd();
				reader.Close();
				reader.Dispose();
				return res;
			}
			catch (Exception)
			{
				return null;
			}
		}

		/// <summary>
		/// get请求
		/// </summary>
		/// <param name="url"></param>
		/// <param name="responseEncoding"></param>
		/// <param name="timeout"></param>
		/// <param name="userAgent"></param>
		/// <param name="cookies"></param>
		/// <param name="Referer"></param>
		/// <param name="headers"></param>
		/// <returns></returns>
		public async Task<string> Get(string url, Encoding responseEncoding, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			HttpWebResponse response = await CreateGetHttpResponse(url, timeout, userAgent, cookies, Referer, headers);

			try
			{
				StreamReader reader = new StreamReader(response.GetResponseStream(), responseEncoding);
				string res = reader.ReadToEnd();
				reader.Close();
				reader.Dispose();

				return res;
			}
			catch (Exception)
			{
				return null;
			}
		}

		/// <summary>
		/// get请求
		/// </summary>
		/// <param name="url"></param>
		/// <param name="timeout"></param>
		/// <param name="userAgent"></param>
		/// <param name="cookies"></param>
		/// <param name="Referer"></param>
		/// <param name="headers"></param>
		/// <returns></returns>
		public async Task<(byte[] by, Dictionary<string, string> header)> GetFile(string url, int? timeout = 300, string userAgent = "", CookieCollection cookies = null, string Referer = "", Dictionary<string, string> headers = null)
		{
			HttpWebResponse response = await CreateGetHttpResponse(url, timeout, userAgent, cookies, Referer, headers);

			Dictionary<string, string> header = new Dictionary<string, string>();

			foreach (string key in response.Headers.AllKeys)
			{
				header.Add(key, response.Headers[key]);
			}

			try
			{
				Stream st = response.GetResponseStream();

				byte[] by = new byte[response.ContentLength];

				st.Read(by, 0, by.Length);

				st.Close();

				return (by, header);
			}
			catch (Exception)
			{
				return (null, header);
			}
		}
	}
}