/*
 * Copyright (C) 2016 Lightbend Inc. <http://www.lightbend.com>
 */

package akka.remote.artery.compress

import akka.actor._
import akka.remote.artery.compress.CompressionProtocol.Events
import akka.testkit._
import akka.util.Timeout
import com.typesafe.config.ConfigFactory
import org.scalatest.BeforeAndAfter
import akka.pattern.ask

import scala.concurrent.Await
import scala.concurrent.duration._

object CompressionIntegrationSpec {
  // need the port before systems are started
  val portB = SocketUtil.temporaryServerAddress("localhost", udp = true).getPort

  val commonConfig = ConfigFactory.parseString(s"""
     akka {
       loglevel = INFO

       actor.provider = "akka.remote.RemoteActorRefProvider"
       remote.artery.enabled = on
       remote.artery.advanced {
         compression.debug = on
       }
       remote.artery.hostname = localhost
       remote.artery.port = 0
       remote.handshake-timeout = 10s

       remote.artery.advanced.compression {
         enabled = on
         actor-refs {
           enabled = on
           advertisement-interval = 3 seconds
         }
       }

     }
  """)

  val configB = ConfigFactory.parseString(s"akka.remote.artery.port = $portB")
    .withFallback(commonConfig)
}

class CompressionIntegrationSpec extends AkkaSpec(CompressionIntegrationSpec.commonConfig)
  with ImplicitSender with BeforeAndAfter {
  import CompressionIntegrationSpec._

  implicit val t = Timeout(3.seconds)
  var systemB: ActorSystem = null

  before {
    systemB = ActorSystem("systemB", configB)
  }

  "Outgoing compression table" must {
    "compress chatty actor" in {
      val messagesToExchange = 10

      // listen for compression table events
      val aProbe = TestProbe()
      val b1Probe = TestProbe()
      system.eventStream.subscribe(aProbe.ref, classOf[CompressionProtocol.Events.Event])
      systemB.eventStream.subscribe(b1Probe.ref, classOf[CompressionProtocol.Events.Event])

      def voidSel = system.actorSelection(s"artery://systemB@localhost:$portB/user/void")
      systemB.actorOf(TestActors.blackholeProps, "void")

      // cause testActor-1 to become a heavy hitter
      (1 to messagesToExchange).foreach { i ⇒ voidSel ! "hello" } // does not reply, but a hot receiver should be advertised

      val a1 = aProbe.expectMsgType[Events.ReceivedActorRefCompressionTable](10.seconds)
      info("System [A] received: " + a1)
      assertCompression[ActorRef](a1.table, 0, _ should ===(system.deadLetters))
      assertCompression[ActorRef](a1.table, 1, _ should ===(testActor))
    }
  }

  def assertCompression[T](table: CompressionTable[T], id: Int, assertion: T ⇒ Unit): Unit = {
    table.map.find(_._2 == id)
      .orElse { throw new AssertionError(s"No key was compressed to the id [$id]! Table was: $table") }
      .foreach(i ⇒ assertion(i._1))
  }

  def identify(_system: String, port: Int, name: String) = {
    val selection =
      system.actorSelection(s"artery://${_system}@localhost:$port/user/$name")
    val ActorIdentity(1, ref) = Await.result(selection ? Identify(1), 3.seconds)
    ref.get
  }

  after {
    shutdownAllActorSystems()
  }

  override def afterTermination(): Unit =
    shutdownAllActorSystems()

  private def shutdownAllActorSystems(): Unit = {
    if (systemB != null) shutdown(systemB)
  }
}