A wrapper for C# HttpClient to consume Asynchronous REST resources

AnalyticsHttpWrapper.cs

public interface IAnalyticsHttpWrapper
{
	Task<T> GetAsynchronous<T>(string path);
}

public class AnalyticsHttpWrapper : IAnalyticsHttpWrapper
{
	private readonly IHttpClientFactory _httpClientFactory;
	private readonly string _httpClientName;
	private readonly HttpClient _httpClient;
	private readonly int _defaultPollingInterval;
	private readonly int _defaultPollingTimeout;

	public AnalyticsHttpWrapper(IHttpClientFactory httpClientFactory)
	{
		_httpClientFactory = httpClientFactory;
		_httpClientName = "AnalyticsAPI";
		_httpClient = _httpClientFactory.CreateClient(_httpClientName);
		_defaultPollingInterval = 2000; // 2 seconds
		_defaultPollingTimeout = 1000*60*45; // 45 mins
	}

	public async Task<T> GetAsynchronous<T>(string path)
	{
		var httpResponse = await PollUntilResourceCreated(path);

		await CheckResourceCreatedResponseOk(httpResponse);

		var jsonContent = await httpResponse.Content.ReadAsStringAsync();
		var responseContent = JsonConvert.DeserializeObject<T>(jsonContent);
		
		return responseContent;
	}

	private async Task<HttpResponseMessage> PollUntilResourceCreated(string path)
	{
		var createResourceResponse = await _httpClient.PostAsync(path, null);
		if (createResourceResponse.StatusCode != System.Net.HttpStatusCode.Accepted)
		{
			var content = await createResourceResponse.Content.ReadAsStringAsync();
			throw new AnalyticsHttpException(
				$"Create resource did not respond with (202): {(int)createResourceResponse.StatusCode}", 
				content);
		}

		var tokenSource = new CancellationTokenSource();
		var cancellationToken = tokenSource.Token;

		var timeoutTask = Task.Delay(_defaultPollingTimeout, cancellationToken);
		var statusLocation = createResourceResponse.Headers.Location;

		HttpResponseMessage httpResponse;
		
		do
		{
			TimeOutCheck(timeoutTask, statusLocation);
			httpResponse = await _httpClient.GetAsync(statusLocation); // should auto redirect to resource location when resource creation completed
			await Task.Delay(_defaultPollingInterval);
		}
		while (httpResponse.StatusCode == System.Net.HttpStatusCode.Accepted);
		
		tokenSource.Cancel(); // Cancel timeout timer
		
		return httpResponse;
	}


	private void TimeOutCheck(Task timeoutTask, Uri location)
	{
		if (timeoutTask.IsCompleted)
		{
			 throw new AnalyticsHttpException(
				@$"Resource queued at {location.ToString()} did not finish after {TimeSpan.FromMilliseconds(_defaultPollingTimeout).TotalMinutes}; aborting");
		}
	}

	private async Task CheckResourceCreatedResponseOk(HttpResponseMessage httpResponse)
	{
		if (httpResponse.StatusCode == System.Net.HttpStatusCode.OK)
		{
			return;
		}
		else
		{
			var content = await httpResponse.Content.ReadAsStringAsync();
			throw new AnalyticsHttpException(
				$"Create resource accepted, but retrieving results responded: {(int)httpResponse.StatusCode}", 
				content);
		}
	}
}

public class AnalyticsHttpException : Exception
{
	public string HttpResponseContent { get; }

	public AnalyticsHttpException(string message, string httpResponseContent) : base(message)
	{
		HttpResponseContent = httpResponseContent;
	}
	public AnalyticsHttpException(string message) : base(message)
	{
	}

}

MyClientClass.cs

public class MyClientClass
{
	private readonly IAnalyticsHttpWrapper _analyticsHttpWrapper;

	public MyClientClass(IAnalyticsHttpWrapper analyticsHttpWrapper)
	{
		_analyticsHttpWrapper = analyticsHttpWrapper;
	}

	public async Task<MyAnalyticsResults> GetAnalyticsReults(int analysisId) 
	{
		return await _analyticsHttpWrapper.GetAsynchronous<MyAnalyticsResults>($"/analysis/{analysisId}/result");
	}
}

Startup.cs

	// in Startup.cs
	
	//...
	using Microsoft.Extensions.DependencyInjection;
	using System.Net.Http;


	public void ConfigureServices(IServiceCollection services)
	{
		
		string analyticsApiUrl = "https://my-R-analytics-api/"

		services.AddHttpClient("AnalyticsAPI", client =>
		{
			client.BaseAddress = new Uri(analyticsApiUrl);
			client.DefaultRequestHeaders.Add("Accept", "application/json");
		})
		.ConfigurePrimaryHttpMessageHandler(() =>
		{
			return new HttpClientHandler()
			{
				AllowAutoRedirect = true
			};
		});;

		services.AddTransient<IAnalyticsHttpWrapper, AnalyticsHttpWrapper >();
		
		//...
	}