package tkocsis.akka.example;

import akka.NotUsed;
import akka.actor.ActorSystem;
import akka.http.javadsl.ConnectHttp;
import akka.http.javadsl.Http;
import akka.http.javadsl.ServerBinding;
import akka.http.javadsl.model.*;
import akka.http.javadsl.server.AllDirectives;
import akka.http.javadsl.server.Route;
import akka.stream.ActorMaterializer;
import akka.stream.javadsl.Flow;
import akka.stream.javadsl.Source;
import akka.util.ByteString;

import java.util.Random;
import java.util.concurrent.CompletionStage;
import java.util.stream.Stream;

public class HttpServerStreamRandomNumbersTest extends AllDirectives {

	public static void main(String[] args) throws Exception {
		// boot up server using the route as defined below
		ActorSystem system = ActorSystem.create("routes");

		final Http http = Http.get(system);
		final ActorMaterializer materializer = ActorMaterializer.create(system);

		// In order to access all directives we need an instance where the
		// routes are define.
		HttpServerStreamRandomNumbersTest app = new HttpServerStreamRandomNumbersTest();

		final Flow<HttpRequest, HttpResponse, NotUsed> routeFlow = app.createRoute().flow(system, materializer);
		final CompletionStage<ServerBinding> binding = http.bindAndHandle(routeFlow,
				ConnectHttp.toHost("localhost", 8080), materializer);

		System.out.println("Server online at http://localhost:8080/\nPress RETURN to stop...");
		System.in.read(); // let it run until user presses return

		binding.thenCompose(ServerBinding::unbind) // trigger unbinding from the
													// port
				.thenAccept(unbound -> system.terminate()); // and shutdown when
															// done
	}

	private Route createRoute() {
		final Random rnd = new Random();
		// streams are re-usable so we can define it here
		// and use it for every request
		Source<Integer, NotUsed> numbers = Source.fromIterator(() -> Stream.generate(rnd::nextInt).iterator());

		return route(path("random",
				() -> get(() -> complete(HttpEntities.create(ContentTypes.TEXT_PLAIN_UTF8,
						// transform each number to a chunk of bytes
						numbers.map(x -> ByteString.fromString(x + "\n")))))));
	}
}