/**
 *  Copyright (C) 2009-2012 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.cluster

import com.typesafe.config.Config
import com.typesafe.config.ConfigFactory
import akka.actor.Address
import akka.remote.testconductor.RoleName
import akka.remote.testkit.MultiNodeSpec
import akka.testkit._
import akka.util.duration._
import akka.util.Duration

object MultiNodeClusterSpec {
  def clusterConfig: Config = ConfigFactory.parseString("""
    akka.cluster {
      auto-down                         = off
      gossip-interval                   = 200 ms
      leader-actions-interval           = 200 ms
      unreachable-nodes-reaper-interval = 200 ms
      periodic-tasks-initial-delay      = 300 ms
      nr-of-deputy-nodes                = 2
    }
    akka.test {
      single-expect-default = 5 s
    }
    """)
}

trait MultiNodeClusterSpec { self: MultiNodeSpec ⇒

  override def initialParticipants = roles.size

  /**
   * Get or create a cluster node using 'Cluster(system)' extension.
   */
  def cluster: Cluster = Cluster(system)

  /**
   * Use this method instead of 'cluster.self'
   * for the initial startup of the cluster node.
   */
  def startClusterNode(): Unit = cluster.self

  /**
   * Initialize the cluster with the specified member
   * nodes (roles). First node will be started first
   * and others will join the first.
   */
  def startCluster(roles: RoleName*): Unit = {
    awaitStartCluster(false, roles.toSeq)
  }

  /**
   * Initialize the cluster of the specified member
   * nodes (roles) and wait until all joined and `Up`.
   * First node will be started first  and others will join
   * the first.
   */
  def awaitClusterUp(roles: RoleName*): Unit = {
    awaitStartCluster(true, roles.toSeq)
  }

  private def awaitStartCluster(upConvergence: Boolean = true, roles: Seq[RoleName]): Unit = {
    runOn(roles.head) {
      // make sure that the node-to-join is started before other join
      startClusterNode()
    }
    testConductor.enter(roles.head.name + "-started")
    if (roles.tail.contains(myself)) {
      cluster.join(node(roles.head).address)
    }
    if (upConvergence && roles.contains(myself)) {
      awaitUpConvergence(numberOfMembers = roles.length)
    }
    testConductor.enter(roles.map(_.name).mkString("-") + "-joined")
  }

  /**
   * Assert that the member addresses match the expected addresses in the
   * sort order used by the cluster.
   */
  def assertMembers(gotMembers: Iterable[Member], expectedAddresses: Address*): Unit = {
    import Member.addressOrdering
    val members = gotMembers.toIndexedSeq
    members.size must be(expectedAddresses.length)
    expectedAddresses.sorted.zipWithIndex.foreach { case (a, i) ⇒ members(i).address must be(a) }
  }

  def assertLeader(nodesInCluster: RoleName*): Unit = if (nodesInCluster.contains(myself)) {
    assertLeaderIn(nodesInCluster)
  }

  /**
   * Assert that the cluster has elected the correct leader
   * out of all nodes in the cluster. First
   * member in the cluster ring is expected leader.
   */
  def assertLeaderIn(nodesInCluster: Seq[RoleName]): Unit = if (nodesInCluster.contains(myself)) {
    nodesInCluster.length must not be (0)
    val expectedLeader = roleOfLeader(nodesInCluster)
    cluster.isLeader must be(ifNode(expectedLeader)(true)(false))
    cluster.status must (be(MemberStatus.Up) or be(MemberStatus.Leaving))
  }

  /**
   * Wait until the expected number of members has status Up and convergence has been reached.
   * Also asserts that nodes in the 'canNotBePartOfMemberRing' are *not* part of the cluster ring.
   */
  def awaitUpConvergence(
    numberOfMembers: Int,
    canNotBePartOfMemberRing: Seq[Address] = Seq.empty[Address],
    timeout: Duration = 20.seconds): Unit = {
    within(timeout) {
      awaitCond(cluster.latestGossip.members.size == numberOfMembers)
      awaitCond(cluster.latestGossip.members.forall(_.status == MemberStatus.Up))
      awaitCond(cluster.convergence.isDefined)
      if (!canNotBePartOfMemberRing.isEmpty) // don't run this on an empty set
        awaitCond(
          canNotBePartOfMemberRing forall (address ⇒ !(cluster.latestGossip.members exists (_.address == address))))
    }
  }

  /**
   * Wait until the specified nodes have seen the same gossip overview.
   */
  def awaitSeenSameState(addresses: Seq[Address]): Unit = {
    awaitCond {
      val seen = cluster.latestGossip.overview.seen
      val seenVectorClocks = addresses.flatMap(seen.get(_))
      seenVectorClocks.size == addresses.size && seenVectorClocks.toSet.size == 1
    }
  }

  def roleOfLeader(nodesInCluster: Seq[RoleName]): RoleName = {
    nodesInCluster.length must not be (0)
    nodesInCluster.sorted.head
  }

  /**
   * Sort the roles in the order used by the cluster.
   */
  implicit val clusterOrdering: Ordering[RoleName] = new Ordering[RoleName] {
    import Member.addressOrdering
    def compare(x: RoleName, y: RoleName) = addressOrdering.compare(node(x).address, node(y).address)
  }

  def roleName(address: Address): Option[RoleName] = {
    testConductor.getNodes.await.find(node(_).address == address)
  }
}