using System.Net;
using System.Text;

namespace DS.Module.Core.Helpers;

/// <summary>
/// 请求帮助类
/// </summary>
public class RequestHelper
{
    public static string Post(string postData, string Url,int timeout = 60000)
    {
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(Url);
        req.Method = "POST";
        req.Timeout = timeout; //设置请求超时时间，单位为毫秒
        req.ContentType = "application/json";

        byte[] data = Encoding.UTF8.GetBytes(postData);

        req.ContentLength = data.Length;

        using (Stream reqStream = req.GetRequestStream())
        {
            reqStream.Write(data, 0, data.Length);

            reqStream.Close();
        }

        HttpWebResponse response = (HttpWebResponse)req.GetResponse();
        Stream stream = response.GetResponseStream();
        Encoding encode = Encoding.UTF8;
        StreamReader reader = new StreamReader(stream, encode);
        string content = reader.ReadToEnd();
        stream.Close();
        reader.Close();
        return content;
    }

    public static string Get(string Url)
    {
        string content = String.Empty;
        HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(Url);
        req.Method = "GET";
        req.ContentType = "text/html;charset=UTF-8";
        HttpWebResponse response = (HttpWebResponse)req.GetResponse();
        Stream stream = response.GetResponseStream();
        Encoding encode = Encoding.UTF8;
        StreamReader reader = new StreamReader(stream, encode);
        content = reader.ReadToEnd();
        stream.Close();
        reader.Close();
        return content;
    }

    public static string GetResponseByGet(string url)
    {
        string result = string.Empty;

        using (HttpClient httpClient = new HttpClient())
        {
            httpClient.DefaultRequestHeaders.Accept.Add(
                new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

            HttpResponseMessage response = httpClient.GetAsync(url).Result;
            //statusCode = response.StatusCode.ToString();

            if (response.IsSuccessStatusCode)
            {
                result = response.Content.ReadAsStringAsync().Result;
            }
        }

        return result;
    }

    /// <summary>
    /// http异步请求
    /// </summary>
    /// <param name="url">url</param>
    /// <param name="reqMethod">请求方法 GET、POST</param>
    /// <param name="callback">回调函数</param>
    /// <param name="ob">回传对象</param>
    /// <param name="postData">post数据</param>
    public static void HttpAsyncRequest(string url, string reqMethod, AsyRequetCallback callback, object ob = null,
        string postData = "")
    {
        Stream requestStream = null;
        try
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.ContentType = "application/x-www-form-urlencoded";
            request.Method = reqMethod;
            if (reqMethod.ToUpper() == "POST")
            {
                byte[] bytes = Encoding.UTF8.GetBytes(postData);
                request.ContentLength = bytes.Length;
                requestStream = request.GetRequestStream();
                requestStream.Write(bytes, 0, bytes.Length);
            }

            //开始调用异步请求
            //AsyResultTag 是自定义类 用于传递调用时信息 其中HttpWebRequest 是必须传递对象。
            //因为回调需要用HttpWebRequest来获取HttpWebResponse
            request.BeginGetResponse(new AsyncCallback(HttpCallback),
                new AsyResultTag() { obj = ob, callback = callback, req = request });
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            if (requestStream != null)
            {
                requestStream.Close();
            }
        }
    }

    /// <summary>
    /// http请求回调 由.net内部调用 参数必须为IAsyncResult
    /// </summary>
    /// <param name="asynchronousResult">http回调时回传对象</param>
    private static void HttpCallback(IAsyncResult asynchronousResult)
    {
        int statusCode = 0;
        string retString = "";
        AsyResultTag tag = new AsyResultTag();
        WebException webEx = null;
        try
        {
            //获取请求时传递的对象
            tag = asynchronousResult.AsyncState as AsyResultTag;
            HttpWebRequest req = tag.req;
            //获取异步返回的http结果
            HttpWebResponse response = req.EndGetResponse(asynchronousResult) as HttpWebResponse;
            Stream myResponseStream = response.GetResponseStream();
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
            retString = myStreamReader.ReadToEnd();
            myStreamReader.Close();
            myResponseStream.Close();
            statusCode = ((int)response.StatusCode);
        }
        catch (WebException ex)
        {
            if ((HttpWebResponse)ex.Response != null)
            {
                statusCode = ((int)((HttpWebResponse)ex.Response).StatusCode);
            }

            webEx = ex;
        }

        //调用外部回调 即最外层的回调
        tag.callback(tag.obj, retString, statusCode, webEx);
    }

    /// <summary>
    /// 异步请求回调委托
    /// </summary>
    /// <param name="asyObj">回传对象</param>
    /// <param name="resStr">http响应结果</param>
    /// <param name="statusCode">http状态码</param>
    /// <param name="webEx">异常</param>
    public delegate void AsyRequetCallback(object asyObj, string respStr, int statusCode, WebException webEx);

    /// <summary>
    /// 异步返回对象
    /// </summary>
    public class AsyResultTag
    {
        /// <summary>
        /// 回传对象
        /// </summary>
        public object obj { get; set; }

        /// <summary>
        /// 当前httpRequest请求实例
        /// </summary>
        public HttpWebRequest req { get; set; }

        /// <summary>
        /// 回调函数委托
        /// </summary>
        public AsyRequetCallback callback { get; set; }
    }
}