using System;

using System.Net;

using System.Net.Http;

using System.Net.Http.Headers;

using System.Threading;

using System.Threading.Tasks;

using Polly;

public class Program

{

    public static HttpClient _httpClient = new HttpClient(new AuthenticationDelegationHandler());

    public class AuthenticationDelegationHandler : DelegatingHandler

    {

        public AuthenticationDelegationHandler()

        {

            InnerHandler = new HttpClientHandler();

        }

        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)

        {

            var policy = Policy

                            .HandleResult<HttpResponseMessage>(message => message.StatusCode != HttpStatusCode.OK)

                            .WaitAndRetryAsync(3, retryAttempt => System.TimeSpan.FromSeconds(1));

​

            return  await policy.ExecuteAsync(async ()=> { 

                request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", "Foo");

                Console.WriteLine("Admin token is used!");

                return await base.SendAsync(request,cancellationToken);});

        }

    }

    public class MyHttpClient : HttpClient

    {

    }

​

    public static void Main()

    {       

         var uri = new Uri("http://google.com");

         var requestMessage = new HttpRequestMessage

            {

                Method = HttpMethod.Delete,

                //Uncomment this for request to succeed and comment out the line above

                //Method = HttpMethod.Get,

                RequestUri = uri

            };

​

            requestMessage.Headers.Authorization = new AuthenticationHeaderValue("Bearer", "Foo");

            Console.WriteLine("User's token is used!");

            var response = _httpClient.SendAsync(requestMessage).Result;

    }

}