using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Text;

namespace Znyc.Recruitment.Admin.Commons.Helpers
{
    /// <summary>
    ///     http请求类
    /// </summary>
    public static class HttpRequestHelper
    {
        /// <summary>
        /// </summary>
        /// <param name="formData"></param>
        /// <param name="stream"></param>
        public static void FillFormDataStream(this Dictionary<string, int> formData, Stream stream)
        {
            string dataString = GetQueryString(formData);
            byte[] formDataBytes = formData == null ? new byte[0] : Encoding.UTF8.GetBytes(dataString);
            stream.Write(formDataBytes, 0, formDataBytes.Length);
            stream.Seek(0, SeekOrigin.Begin); //设置指针读取位置
        }

        /// <summary>
        ///     组装QueryString的方法
        ///     参数之间用&amp;连接，首位没有符号，如：a=1&amp;b=2&amp;c=3
        /// </summary>
        /// <param name="formData"></param>
        /// <returns></returns>
        public static string GetQueryString(this Dictionary<string, int> formData)
        {
            if (formData == null || formData.Count == 0)
            {
                return "";
            }

            StringBuilder sb = new StringBuilder();
            int i = 0;
            foreach (KeyValuePair<string, int> kv in formData)
            {
                i++;
                sb.AppendFormat("{0}={1}", kv.Key, kv.Value);
                if (i < formData.Count)
                {
                    sb.Append("&");
                }
            }

            return sb.ToString();
        }

        #region 同步方法

        /// <summary>
        ///     使用Get方法获取字符串结果
        /// </summary>
        /// <param name="url"></param>
        /// <param name="encoding"></param>
        /// <param name="timeOut"></param>
        /// <returns></returns>
        public static string HttpGet(string url, Encoding encoding = null, int timeOut = 60000)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "GET";
            request.Timeout = timeOut;
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            using (Stream responseStream = response.GetResponseStream())
            {
                using (StreamReader myStreamReader = new StreamReader(responseStream, encoding ?? Encoding.GetEncoding("utf-8")))
                {
                    string retString = myStreamReader.ReadToEnd();
                    return retString;
                }
            }
        }

        /// <summary>
        ///     使用Post方法获取字符串结果，常规提交
        /// </summary>
        /// <returns></returns>
        public static string HttpPost(string url, Dictionary<string, int> formData = null, Encoding encoding = null,
            int timeOut = 60000, Dictionary<string, string> headers = null)
        {
            MemoryStream ms = new MemoryStream();
            formData.FillFormDataStream(ms); //填充formData
            return HttpPost(url, ms, "application/x-www-form-urlencoded", encoding, headers, timeOut);
        }

        /// <summary>
        ///     发送HttpPost请求，使用JSON格式传输数据
        /// </summary>
        /// <param name="url"></param>
        /// <param name="postData"></param>
        /// <param name="encoding"></param>
        /// <param name="headers"></param>
        /// <returns></returns>
        public static string HttpPost(string url, string postData, Encoding encoding = null,
            Dictionary<string, string> headers = null)
        {
            if (encoding == null)
            {
                encoding = Encoding.UTF8;
            }

            if (string.IsNullOrWhiteSpace(postData))
            {
                throw new ArgumentNullException("postData");
            }

            byte[] data = encoding.GetBytes(postData);
            MemoryStream stream = new MemoryStream();
            byte[] formDataBytes = postData == null ? new byte[0] : Encoding.UTF8.GetBytes(postData);
            stream.Write(formDataBytes, 0, formDataBytes.Length);
            stream.Seek(0, SeekOrigin.Begin); //设置指针读取位置
            return HttpPost(url, stream, "application/json", encoding, headers);
        }

        /// <summary>
        ///     使用POST请求数据，使用JSON传输数据
        /// </summary>
        /// <param name="url"></param>
        /// <param name="dataObj">传输对象，转换为JSON传输</param>
        /// <param name="encoding"></param>
        /// <returns></returns>
        public static string HttpPost(string url, object dataObj, Encoding encoding = null,
            Dictionary<string, string> headers = null)
        {
            if (encoding == null)
            {
                encoding = Encoding.UTF8;
            }

            if (dataObj == null)
            {
                throw new ArgumentNullException("dataObj");
            }

            string postData = JsonConvert.SerializeObject(dataObj,
                new JsonSerializerSettings { DateFormatString = "yyyy-MM-dd HH:mm:ss" });
            byte[] data = encoding.GetBytes(postData);
            MemoryStream stream = new MemoryStream();
            byte[] formDataBytes = postData == null ? new byte[0] : Encoding.UTF8.GetBytes(postData);
            stream.Write(formDataBytes, 0, formDataBytes.Length);
            stream.Seek(0, SeekOrigin.Begin); //设置指针读取位置
            return HttpPost(url, stream, "application/json", encoding, headers);
        }

        /// <summary>
        ///     使用Post方法获取字符串结果
        /// </summary>
        /// <param name="url"></param>
        /// <param name="postStream"></param>
        /// <param name="contentType"></param>
        /// <param name="encoding"></param>
        /// <param name="headers"></param>
        /// <param name="timeOut"></param>
        /// <returns></returns>
        public static string HttpPost(string url, Stream postStream = null,
            string contentType = "application/x-www-form-urlencoded", Encoding encoding = null,
            Dictionary<string, string> headers = null, int timeOut = 60000)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "POST";
            request.Timeout = timeOut;

            request.ContentLength = postStream != null ? postStream.Length : 0;
            request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";
            request.KeepAlive = false;

            request.UserAgent =
                "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.87 Safari/537.36 QQBrowser/9.2.5748.400";
            request.ContentType = contentType;

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

            #region 输入二进制流

            if (postStream != null)
            {
                postStream.Position = 0;

                //直接写入流
                Stream requestStream = request.GetRequestStream();

                byte[] buffer = new byte[1024];
                int bytesRead = 0;
                while ((bytesRead = postStream.Read(buffer, 0, buffer.Length)) != 0)
                {
                    requestStream.Write(buffer, 0, bytesRead);
                }

                postStream.Close(); //关闭文件访问
            }

            #endregion 输入二进制流

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            using (Stream responseStream = response.GetResponseStream())
            {
                using (StreamReader myStreamReader = new StreamReader(responseStream, encoding ?? Encoding.GetEncoding("utf-8")))
                {
                    string retString = myStreamReader.ReadToEnd();
                    return retString;
                }
            }
        }

        #endregion 同步方法
    }
}