Account Activity - HttpServer

During the registration process of a webhook url, Twitter will send an http request to your webhook url.
This request is called a CRC request. Twitter expect your application to send a response containing a special authentication token.

Tweetinvi offer a RequestHandler that checks all incoming http requests to your server.
When the RequestHandler identifies that a request should be handled by Tweetinvi (like the CRC request), tweetinvi will take care of the response for you.

In addition the RequestHandler will filter and route the twitter requests containing user events.

SimpleHttpServer.cs

using System;
using System.Net;
using System.Threading.Tasks;

namespace tweetinvi_hello_world
{
    public class SimpleHttpServer : IDisposable
    {
        private readonly HttpListener _server;

        public SimpleHttpServer(int port)
        {
            _server = new HttpListener();
            _server.Prefixes.Add("http://*:" + port + "/");
        }

        public EventHandler<HttpListenerContext> OnRequest;

        public void Start()
        {
            _server.Start();
            RunServerAsync(); // do not await
        }

        private async Task RunServerAsync()
        {
            while (_server.IsListening)
            {
                var context = await _server.GetContextAsync();
                OnRequest?.Invoke(this, context);
            }
        }

        public async Task WaitUntilDisposed()
        {
            while (!_disposed)
            {
                await Task.Delay(200);
            }
        }

        private bool _disposed;
        public void Dispose()
        {
            _disposed = true;
            ((IDisposable) _server)?.Dispose();
        }
    }
}

Here is a sample server capable of handling twitter requests.

Plugins.Add<AspNetPlugin>();

var appClient = new TwitterClient(appCredsWithBearerToken);
var userClient = new TwitterClient(userCreds);

var accountActivityHandler = appClient.AccountActivity.CreateRequestHandler();

var httpServer = new SimpleHttpServer(8042);
httpServer.OnRequest += async (sender, context) =>
{
    var webhookRequest = WebhookRequestFactory.Create(context);

    // check if the request comes from twitter
    if (await accountActivityHandler.IsRequestManagedByTweetinviAsync(webhookRequest))
    {
        // let tweetinvi manage the twitter requests and respond to it
        await accountActivityHandler.TryRouteRequestAsync(webhookRequest);
    }
    else
    {
        // a request not coming from twitter (probably for a user of your website)
        var streamWriter = new StreamWriter(context.Response.OutputStream);
        await streamWriter.WriteAsync("Hello friend, this page does not exists!");
        await streamWriter.FlushAsync();
        context.Response.StatusCode = 404;
        context.Response.Close();
    }
};

httpServer.Start();

await httpServer.WaitUntilDisposed();