using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.Extensions.Logging;
using System;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Threading.Tasks;

namespace NDB.Logging.Api
{
    public class RequestLoggingAttribute : ActionFilterAttribute
    {
        private readonly ILogger<RequestLoggingAttribute> _logger;

        public RequestLoggingAttribute(ILogger<RequestLoggingAttribute> logger)
        {
            _logger = logger;
        }

        public override async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
        {
            var stopWatch = new Stopwatch();
            stopWatch.Start();

            var uid = Guid.NewGuid();
            var request = (HttpRequest)((ControllerBase)context.Controller).Request;
            var requestUrl = request.Path;

            if (request.QueryString != null && request.QueryString.HasValue)
                requestUrl += request.QueryString.ToString();

            var logContent = $"Start request {uid} for method {requestUrl}";

            if (request.Method == WebRequestMethods.Http.Post)
            {
                var requestBody = await GetRequestBody(request);
                logContent += $" with body {requestBody}";
            }

            _logger.LogInformation(logContent);

            var resultContext = await next();
            stopWatch.Stop();

            if (resultContext.Exception != null)
                _logger.LogError(resultContext.Exception, $"Request {uid} for method {requestUrl} failed - {resultContext.Exception.Message}");

            _logger.LogInformation($"End request {uid} for method {requestUrl}");
            _logger.LogDebug($"Request {uid} duration: {stopWatch.ElapsedMilliseconds:N0} ms");
        }

        private async Task<string> GetRequestBody(HttpRequest request)
        {
            if (request.ContentLength == 0)
                return "-";

            using (var body = new StreamReader(request.Body))
            {
                body.BaseStream.Seek(0, SeekOrigin.Begin);
                var bodyStr = await body.ReadToEndAsync();

                return bodyStr;
            }
        }
    }
}