using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using System;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using VOL.Core.Enums;
using VOL.Core.Services;

namespace VOL.Core.Middleware
{
    /// <summary>
    /// 接口输入输出日志中间件
    /// </summary>
    public class RequestResponseLoggingMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger<RequestResponseLoggingMiddleware> _logger;

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

        public async Task InvokeAsync(HttpContext context)
        {
            DateTime now = DateTime.Now;

            // Log the request
            var request = await HttpRequestResponseFormat.FormatRequest(context.Request);
            _logger.LogInformation($"HTTP Request Information:{Environment.NewLine}{now} {request}");

            // Copy a pointer to the original response body stream
            var originalBodyStream = context.Response.Body;

            // Create a new memory stream to hold the response body
            using (var responseBody = new MemoryStream())
            {
                context.Response.Body = responseBody;
                await _next(context);

                // Log the response
                string response = await HttpRequestResponseFormat.FormatResponse(context.Response);
                Logger.OK(LoggerType.Info, request, response);
                _logger.LogInformation($"HTTP Response Information:{Environment.NewLine}{now} {response}");

                // Copy the contents of the new memory stream (which contains the response) to the original stream
                await responseBody.CopyToAsync(originalBodyStream);
            }
        }
    }

    public sealed class HttpRequestResponseFormat
    {
        public static async Task<string> FormatRequest(HttpRequest request)
        {
            request.EnableBuffering();

            // 二进制内容判断可保留
            if (request.ContentType != null &&
                (request.ContentType.Contains("multipart/form-data") || request.ContentType.Contains("application/octet-stream")))
            {
                return $"{request.Scheme} {request.Host}{request.Path} {request.QueryString} [二进制数据不可读]";
            }

            using var reader = new StreamReader(request.Body, Encoding.UTF8, leaveOpen: true);
            var bodyAsText = await reader.ReadToEndAsync();
            request.Body.Position = 0;

            return $"{request.Scheme} {request.Host}{request.Path} {request.QueryString} {bodyAsText}";
        }

        public static async Task<string> FormatResponse(HttpResponse response)
        {
            response.Body.Seek(0, SeekOrigin.Begin);

            if (response.ContentType != null && response.ContentType.Contains("application/octet-stream"))
            {
                return $"StatusCode: {response.StatusCode}, Body: 二进制数据不可读";
            }

            using var reader = new StreamReader(response.Body, Encoding.UTF8, leaveOpen: true);
            var text = await reader.ReadToEndAsync();
            response.Body.Seek(0, SeekOrigin.Begin);

            return $"StatusCode: {response.StatusCode}, Body: {text}";
        }
    }
}