/**
 *  Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.cluster

import language.postfixOps
import scala.collection.immutable
import scala.concurrent.duration._
import com.typesafe.config.ConfigFactory
import akka.actor.ActorSystem
import akka.actor.ExtendedActorSystem
import akka.remote.testconductor.RoleName
import akka.remote.testkit.MultiNodeConfig
import akka.remote.testkit.MultiNodeSpec
import akka.remote.transport.ThrottlerTransportAdapter.Direction
import akka.testkit._
import akka.actor.Actor
import akka.actor.ActorRef
import akka.actor.Props
import akka.actor.RootActorPath

object UnreachableNodeJoinsAgainMultiNodeConfig extends MultiNodeConfig {
  val first = role("first")
  val second = role("second")
  val third = role("third")
  val fourth = role("fourth")

  commonConfig(ConfigFactory.parseString(
    """
      # this setting is here to limit the number of retries and failures while the
      # node is being blackholed
      akka.remote.retry-gate-closed-for = 500 ms

      akka.remote.log-remote-lifecycle-events = off
      akka.cluster.publish-stats-interval = 0s
    """).withFallback(debugConfig(on = false).withFallback(MultiNodeClusterSpec.clusterConfig)))

  testTransport(on = true)

  class EndActor(testActor: ActorRef) extends Actor {
    def receive = { case msg ⇒ testActor forward msg }
  }
}

class UnreachableNodeJoinsAgainMultiJvmNode1 extends UnreachableNodeJoinsAgainSpec
class UnreachableNodeJoinsAgainMultiJvmNode2 extends UnreachableNodeJoinsAgainSpec
class UnreachableNodeJoinsAgainMultiJvmNode3 extends UnreachableNodeJoinsAgainSpec
class UnreachableNodeJoinsAgainMultiJvmNode4 extends UnreachableNodeJoinsAgainSpec

abstract class UnreachableNodeJoinsAgainSpec
  extends MultiNodeSpec(UnreachableNodeJoinsAgainMultiNodeConfig)
  with MultiNodeClusterSpec {

  import UnreachableNodeJoinsAgainMultiNodeConfig._

  muteMarkingAsUnreachable()

  def allBut(role: RoleName, roles: immutable.Seq[RoleName] = roles): immutable.Seq[RoleName] = {
    roles.filterNot(_ == role)
  }

  lazy val master = second
  lazy val victim = fourth

  var endBarrierNumber = 0
  def endBarrier(): Unit = {
    endBarrierNumber += 1
    enterBarrier("after_" + endBarrierNumber)
  }

  "A cluster of " + roles.size + " members" must {

    "reach initial convergence" taggedAs LongRunningTest in {
      awaitClusterUp(roles: _*)
      endBarrier()
    }

    "mark a node as UNREACHABLE when we pull the network" taggedAs LongRunningTest in {
      // let them send at least one heartbeat to each other after the gossip convergence
      // because for new joining nodes we remove them from the failure detector when
      // receive gossip
      Thread.sleep(2.seconds.dilated.toMillis)

      runOn(first) {
        // pull network for victim node from all nodes
        allBut(victim).foreach { roleName ⇒
          testConductor.blackhole(victim, roleName, Direction.Both).await
        }
      }

      enterBarrier("unplug_victim")

      val allButVictim = allBut(victim, roles)
      runOn(victim) {
        allButVictim.foreach(markNodeAsUnavailable(_))
        within(30 seconds) {
          // victim becomes all alone
          awaitAssert {
            val members = clusterView.members
            clusterView.unreachableMembers.size must be(roles.size - 1)
            members.size must be(1)
            members.map(_.status) must be(Set(MemberStatus.Up))
          }
          clusterView.unreachableMembers.map(_.address) must be((allButVictim map address).toSet)
        }
      }

      runOn(allButVictim: _*) {
        markNodeAsUnavailable(victim)
        within(30 seconds) {
          // victim becomes unreachable
          awaitAssert {
            val members = clusterView.members
            clusterView.unreachableMembers.size must be(1)
            members.size must be(roles.size - 1)
            members.map(_.status) must be(Set(MemberStatus.Up))
          }
          awaitSeenSameState(allButVictim map address: _*)
          // still one unreachable
          clusterView.unreachableMembers.size must be(1)
          clusterView.unreachableMembers.head.address must be(node(victim).address)
        }
      }

      endBarrier()
    }

    "mark the node as DOWN" taggedAs LongRunningTest in {
      runOn(master) {
        cluster down victim
      }

      runOn(allBut(victim): _*) {
        awaitMembersUp(roles.size - 1, Set(victim))
        // eventually removed
        awaitAssert(clusterView.unreachableMembers must be(Set.empty), 15 seconds)

      }

      endBarrier()
    }

    "allow fresh node with same host:port to join again when the network is plugged back in" taggedAs LongRunningTest in {
      val expectedNumberOfMembers = roles.size

      // victim actor system will be shutdown, not part of testConductor any more
      // so we can't use barriers to synchronize with it
      val masterAddress = address(master)
      runOn(master) {
        system.actorOf(Props(classOf[EndActor], testActor), "end")
      }
      enterBarrier("end-actor-created")

      runOn(first) {
        // put the network back in
        allBut(victim).foreach { roleName ⇒
          testConductor.passThrough(victim, roleName, Direction.Both).await
        }
      }

      enterBarrier("plug_in_victim")

      runOn(first) {
        // will shutdown ActorSystem of victim
        testConductor.removeNode(victim)
      }

      runOn(victim) {
        val victimAddress = system.asInstanceOf[ExtendedActorSystem].provider.getDefaultAddress
        system.shutdown()
        system.awaitTermination(10 seconds)
        Thread.sleep(5000)
        // create new ActorSystem with same host:port
        val freshSystem = ActorSystem(system.name, ConfigFactory.parseString(s"""
            akka.remote.netty.tcp {
              hostname = ${victimAddress.host.get}
              port = ${victimAddress.port.get}
            }
            """).withFallback(system.settings.config))

        try {
          Cluster(freshSystem).join(masterAddress)
          Thread.sleep(5000)
          within(15 seconds) {
            awaitAssert(Cluster(freshSystem).readView.members.map(_.address) must contain(victimAddress))
            awaitAssert(Cluster(freshSystem).readView.members.size must be(expectedNumberOfMembers))
            awaitAssert(clusterView.members.map(_.status) must be(Set(MemberStatus.Up)))
          }
          freshSystem.actorSelection(RootActorPath(master) / "user" / "end") ! "done"
        } finally {
          freshSystem.shutdown()
          freshSystem.awaitTermination(10 seconds)
        }
        // no barrier here, because it is not part of testConductor roles any more
      }

      runOn(allBut(victim): _*) {
        awaitMembersUp(expectedNumberOfMembers)
        // don't end the test until the freshSystem is done
        runOn(master) {
          expectMsg("done")
        }
        endBarrier()
      }

    }
  }
}