/*
 * =========================================================================================
 * Copyright © 2013-2014 the kamon project <http://kamon.io/>
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language governing permissions
 * and limitations under the License.
 * =========================================================================================
 */

package kamon.trace

import akka.actor.{ Terminated, ActorRef, Actor }

class TraceSubscriptions extends Actor {
  import TraceSubscriptions._

  var subscribers: List[ActorRef] = Nil

  def receive = {
    case Subscribe(newSubscriber) ⇒
      if (!subscribers.contains(newSubscriber))
        subscribers = context.watch(newSubscriber) :: subscribers

    case Unsubscribe(leavingSubscriber) ⇒
      subscribers = subscribers.filter(_ == leavingSubscriber)

    case Terminated(terminatedSubscriber) ⇒
      subscribers = subscribers.filter(_ == terminatedSubscriber)

    case trace: TraceInfo ⇒
      subscribers.foreach(_ ! trace)
  }
}

object TraceSubscriptions {
  case class Subscribe(subscriber: ActorRef)
  case class Unsubscribe(subscriber: ActorRef)
}