/*
 * Copyright (C) 2015-2016 Typesafe Inc. <http://www.typesafe.com>
 */
package docs.stream;

import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Props;
import akka.japi.pf.ReceiveBuilder;
import akka.stream.ActorMaterializer;
import akka.stream.Materializer;
import akka.stream.actor.AbstractActorPublisher;
import akka.stream.actor.ActorPublisherMessage;
import akka.stream.javadsl.Sink;
import akka.stream.javadsl.Source;
import akka.testkit.JavaTestKit;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

public class ActorPublisherDocTest {

  static ActorSystem system;


  @BeforeClass
  public static void setup() {
    system = ActorSystem.create("ActorPublisherDocTest");
  }

  @AfterClass
  public static void tearDown() {
    JavaTestKit.shutdownActorSystem(system);
    system = null;
  }

  final Materializer mat = ActorMaterializer.create(system);

    //#job-manager
    public static class JobManagerProtocol {
      final public static class Job {
        public final String payload;

        public Job(String payload) {
          this.payload = payload;
        }

      }

      public static class JobAcceptedMessage {
        @Override
        public String toString() {
          return "JobAccepted";
        }
      }
      public static final JobAcceptedMessage JobAccepted = new JobAcceptedMessage();

      public static class JobDeniedMessage {
        @Override
        public String toString() {
          return "JobDenied";
        }
      }
      public static final JobDeniedMessage JobDenied = new JobDeniedMessage();
    }
    public static class JobManager extends AbstractActorPublisher<JobManagerProtocol.Job> {

      public static Props props() { return Props.create(JobManager.class); }

      private final int MAX_BUFFER_SIZE = 100;
      private final List<JobManagerProtocol.Job> buf = new ArrayList<>();

      public JobManager() {
        receive(ReceiveBuilder.
          match(JobManagerProtocol.Job.class, job -> buf.size() == MAX_BUFFER_SIZE, job -> {
            sender().tell(JobManagerProtocol.JobDenied, self());
          }).
          match(JobManagerProtocol.Job.class, job -> {
            sender().tell(JobManagerProtocol.JobAccepted, self());

            if (buf.isEmpty() && totalDemand() > 0)
              onNext(job);
            else {
              buf.add(job);
              deliverBuf();
            }
          }).
          match(ActorPublisherMessage.Request.class, request -> deliverBuf()).
          match(ActorPublisherMessage.Cancel.class, cancel -> context().stop(self())).
          build());
      }

      void deliverBuf() {
        while (totalDemand() > 0) {
            /*
             * totalDemand is a Long and could be larger than
             * what buf.splitAt can accept
             */
          if (totalDemand() <= Integer.MAX_VALUE) {
            final List<JobManagerProtocol.Job> took =
              buf.subList(0, Math.min(buf.size(), (int) totalDemand()));
            took.forEach(this::onNext);
            buf.removeAll(took);
            break;
          } else {
            final List<JobManagerProtocol.Job> took =
              buf.subList(0, Math.min(buf.size(), Integer.MAX_VALUE));
            took.forEach(this::onNext);
            buf.removeAll(took);
          }
        }
      }
    }
    //#job-manager

  @Test
  public void demonstrateActorPublisherUsage() {
    new JavaTestKit(system) {
      private final SilenceSystemOut.System System = SilenceSystemOut.get(getTestActor());

      {
        //#actor-publisher-usage
        final Source<JobManagerProtocol.Job, ActorRef> jobManagerSource =
          Source.actorPublisher(JobManager.props());

        final ActorRef ref = jobManagerSource
          .map(job -> job.payload.toUpperCase())
          .map(elem -> {
            System.out.println(elem);
            return elem;
          })
          .to(Sink.ignore())
          .run(mat);

        ref.tell(new JobManagerProtocol.Job("a"), ActorRef.noSender());
        ref.tell(new JobManagerProtocol.Job("b"), ActorRef.noSender());
        ref.tell(new JobManagerProtocol.Job("c"), ActorRef.noSender());
        //#actor-publisher-usage

        expectMsgEquals("A");
        expectMsgEquals("B");
        expectMsgEquals("C");
      }
    };
  }

}