Retry on Unauthorized issue

RetryOnUnauthorizedMessageHandler.cs

httpClient = new HttpClient(new RetryOnUnauthorizedMessageHandler(new HttpClientHandler()));

/// <summary>
/// See https://stackoverflow.com/a/49304655
/// </summary>
public class RetryOnUnauthorizedMessageHandler : DelegatingHandler
{
    public RetryOnUnauthorizedMessageHandler(HttpMessageHandler innerHandler) : base(innerHandler)
    {
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
        CancellationToken cancellationToken)
    {
        var response = await base.SendAsync(request, cancellationToken);
        //test for 401 and actual bearer token in initial request
        var wasAuthorized = !string.IsNullOrWhiteSpace(request.Headers.Authorization?.Parameter);


        if (response.StatusCode != HttpStatusCode.Unauthorized || !wasAuthorized) return response; // authorized or no token is needed

        //if 401

        try
        {
            var log = Mvx.Resolve<IMvxLog>();
            log.Info("Got Unauthorized, trying to refresh token");
            var uow = Mvx.Resolve<IUnitOfWork>();
            var model = uow.Token.Get();
            var data = new Dictionary<string, string>
            {
                {"grant_type", "refresh_token"},
                {"refresh_token", model.RefreshToken}
            };
            var requestUri = new Uri($"{Constants.UriAuthApi}api/token");
            var requestMessage = new HttpRequestMessage(HttpMethod.Post, requestUri)
            {
                Content = new FormUrlEncodedContent(data)
            };
            using (var refreshResponse = await base.SendAsync(requestMessage, cancellationToken).ConfigureAwait(false))
            {
                if (refreshResponse.StatusCode == HttpStatusCode.Unauthorized)
                {
                    log.Error("Refresh token is not valid. Signing out");
                    await Mvx.Resolve<IMvxNavigationService>()
                        .CustomNavigate<LoginContainerViewModel>(NavigationType.ClearBackstack);
                }
                else if(refreshResponse.IsSuccessStatusCode)
                {
                    var rawResponse = await refreshResponse.Content.ReadAsStringAsync();
                    var authModel = JsonConvert.DeserializeObject<AuthModel>(rawResponse);
                    log.Info($"Successfully refreshed token: {authModel.AccessToken.Substring(0, 7)}...");
                    request.Headers.Remove("Authorization");
                    request.Headers.Add("Authorization", "bearer " + authModel.AccessToken);
                    if (uow.Token.Update(authModel))
                    {
                        log.Info("Token saved, retying initial request...");
                        response = await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
                    }
                }
                else
                {
                    //TODO
                }

            }
            return response;
        }
        catch (Exception e)
        {
            Analytics.TrackEvent("Token refresh failed");
            throw e;
        }
    }
}

//when creating httpClient like this - requests are very slow
httpClient = new HttpClient(new RetryOnUnauthorizedMessageHandler(new HttpClientHandler())); 
//but when doing like this - everything works fast (but no desired behaviour)
httpClient = new HttpClient(new HttpClientHandler());