using System;
using System.IO;

namespace WebApi.Restful.Middlewares
{
    public class MemoryWrappedHttpResponseStream : MemoryStream
    {
        private Stream _innerStream;
        public MemoryWrappedHttpResponseStream(Stream innerStream)
        {
            this._innerStream = innerStream ?? throw new ArgumentNullException(nameof(innerStream));
        }
        public override void Flush()
        {
            this._innerStream.Flush();
            base.Flush();
        }

        public override void Write(byte[] buffer, int offset, int count)
        {
            base.Write(buffer, offset, count);
            this._innerStream.Write(buffer, offset, count);
        }

        protected override void Dispose(bool disposing)
        {
            base.Dispose(disposing);
            if (disposing)
            {
                this._innerStream.Dispose();
            }
        }

        public override void Close()
        {
            base.Close();
            this._innerStream.Close();
        }
    }
}

using Exceptionless;
using gateway.api;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Formatters;
using Microsoft.AspNetCore.WebUtilities;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net.Http;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace WebApi.Restful.Middlewares
{

    
    /// <summary>
    /// 请求日志记录中间件
    /// </summary>
    public class RequestLoggingMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger _logger;

        public RequestLoggingMiddleware(RequestDelegate next,
            ILogger<RequestLoggingMiddleware> logger)
        {
            _next = next;
            _logger = logger;

        }

        public async Task Invoke(HttpContext context)
        {
            context.TraceIdentifier = Guid.NewGuid().ToString("N");

            var request = context.Request;

            await RequestEnableRewindAsync(request).ConfigureAwait(false);
            var encoding = GetRequestEncoding(request);
            var requestContent = await ReadStreamAsync(request.Body, encoding).ConfigureAwait(false);
            WritLog(context, JsonConvert.SerializeObject(requestContent));

            await ResponseEnableRewindAsync(context.Response);
            context.Response.OnCompleted(ResponseCompletedCallback, context);
            await _next(context);
        }

        private async Task ResponseCompletedCallback(object obj)
        {
            if (obj is HttpContext context)
            {
                var response = await ResponseReadStreamAsync(context.Response);
　　  　　 　　   //记录日志
                //ExceptionlessClient.Default.CreateLog(JsonConvert.SerializeObject(response)).AddTags(context.TraceIdentifier).Submit();
            }

        }
        private async Task<string> ResponseReadStreamAsync(HttpResponse response)
        {
            if (response.Body.Length > 0)
            {
                response.Body.Seek(0, SeekOrigin.Begin);
                var encoding = GetEncoding(response.ContentType);
                var retStr = await ReadStreamAsync(response.Body, encoding, false).ConfigureAwait(false);
                return retStr;
            }
            return null;
        }
        private async Task<string> ReadStreamAsync(Stream stream, Encoding encoding, bool forceSeekBeginZero = true)
        {
            using (StreamReader sr = new StreamReader(stream, encoding, true, 1024, true))//这里注意Body部分不能随StreamReader一起释放
            {
                var str = await sr.ReadToEndAsync();
                if (forceSeekBeginZero)
                {
                    stream.Seek(0, SeekOrigin.Begin);//内容读取完成后需要将当前位置初始化，否则后面的InputFormatter会无法读取
                }
                return str;
            }
        }
        private void WritLog(HttpContext context, string body)
        {
            var request = context.Request;
            try
            {
                Task.Factory.StartNew(() =>
                {
                    LogMode logMode = new LogMode
                    {
                        Body = body,
                        CententLength = request.ContentLength,
                        CententType = request.ContentType,
                        Headers = JsonConvert.SerializeObject(request.Headers),
                        Host = request.Host.Host,
                        Method = request.Method,
                        Path = request.Path,
                        Query = JsonConvert.SerializeObject(request.Query)
                    };
 　　　　　　　　　　 // 记录日志
                   // ExceptionlessClient.Default.CreateLog(JsonConvert.SerializeObject(logMode)).AddTags(context.TraceIdentifier).Submit();
                });
            }
            catch (Exception ex)
            {
　　　　　　　　　　//记录日志
                 //ex.ToExceptionless().Submit();
            }

        }

        private async Task ResponseEnableRewindAsync(HttpResponse response)
        {
            if (!response.Body.CanRead || !response.Body.CanSeek)
            {
                response.Body = new MemoryWrappedHttpResponseStream(response.Body);
            }
        }

        private async Task RequestEnableRewindAsync(HttpRequest request)
        {
            if (!request.Body.CanSeek)
            {
                request.EnableBuffering();

                await request.Body.DrainAsync(CancellationToken.None);
                request.Body.Seek(0L, SeekOrigin.Begin);
            }
        }

        private async Task<string> ReadStreamAsync(Stream stream, Encoding encoding)
        {
            using (StreamReader sr = new StreamReader(stream, encoding, true, 1024, true))//这里注意Body部分不能随StreamReader一起释放
            {
                var str = await sr.ReadToEndAsync();
                stream.Seek(0, SeekOrigin.Begin);//内容读取完成后需要将当前位置初始化，否则后面的InputFormatter会无法读取
                return str;
            }
        }

        private Encoding GetRequestEncoding(HttpRequest request)
        {
            var requestContentType = request.ContentType;
            var requestMediaType = requestContentType == null ? default(MediaType) : new MediaType(requestContentType);
            var requestEncoding = requestMediaType.Encoding;
            if (requestEncoding == null)
            {
                requestEncoding = Encoding.UTF8;
            }
            return requestEncoding;
        }


        private Encoding GetEncoding(string contentType)
        {
            var mediaType = contentType == null ? default(MediaType) : new MediaType(contentType);
            var encoding = mediaType.Encoding;
            if (encoding == null)
            {
                encoding = Encoding.UTF8;
            }
            return encoding;
        }
        public class LogMode
        {
            public string Body { get; set; }
            public long? CententLength { get; set; }
            public string CententType { get; set; }
            public string Headers { get; set; }
            public string Host { get; set; }
            public string Method { get; set; }
            public string Path { get; set; }
            public string Query { get; set; }
        }

        private Dictionary<string, IEnumerable<string>> GetHeaders(HttpRequestMessage request)
        {
            var result = new Dictionary<string, IEnumerable<string>>();
            foreach (var pair in request.Headers)
            {
                result.Add(pair.Key, pair.Value);
            }
            return result;
        }
    }
}