/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hadoop.yarn.server.resourcemanager.scheduler;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.apache.hadoop.yarn.api.records.Container;
import org.apache.hadoop.yarn.api.records.ContainerId;
import org.apache.hadoop.yarn.exceptions.YarnException;
import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
import org.apache.hadoop.yarn.server.resourcemanager.rmcontainer.RMContainer;
import org.apache.hadoop.yarn.util.resource.Resources;

public abstract class AbstractYarnScheduler implements ResourceScheduler {

  protected RMContext rmContext;
  protected Map<ApplicationId, SchedulerApplication> applications;
  protected final static List<Container> EMPTY_CONTAINER_LIST =
      new ArrayList<Container>();
  protected static final Allocation EMPTY_ALLOCATION = new Allocation(
    EMPTY_CONTAINER_LIST, Resources.createResource(0), null, null, null);

  public synchronized List<Container> getTransferredContainers(
      ApplicationAttemptId currentAttempt) {
    ApplicationId appId = currentAttempt.getApplicationId();
    SchedulerApplication app = applications.get(appId);
    List<Container> containerList = new ArrayList<Container>();
    RMApp appImpl = this.rmContext.getRMApps().get(appId);
    if (appImpl.getApplicationSubmissionContext().getUnmanagedAM()) {
      return containerList;
    }
    Collection<RMContainer> liveContainers =
        app.getCurrentAppAttempt().getLiveContainers();
    ContainerId amContainerId =
        rmContext.getRMApps().get(appId).getCurrentAppAttempt()
          .getMasterContainer().getId();
    for (RMContainer rmContainer : liveContainers) {
      if (!rmContainer.getContainerId().equals(amContainerId)) {
        containerList.add(rmContainer.getContainer());
      }
    }
    return containerList;
  }

  public Map<ApplicationId, SchedulerApplication> getSchedulerApplications() {
    return applications;
  }
  
  @Override
  public String moveApplication(ApplicationId appId, String newQueue)
      throws YarnException {
    throw new YarnException(getClass().getSimpleName()
        + " does not support moving apps between queues");
  }
}