/**
 * 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.api.protocolrecords;

import java.nio.ByteBuffer;
import java.util.Map;

import org.apache.hadoop.classification.InterfaceAudience.Private;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Stable;
import org.apache.hadoop.classification.InterfaceStability.Unstable;
import org.apache.hadoop.yarn.api.ApplicationMasterProtocol;
import org.apache.hadoop.yarn.api.records.ApplicationAccessType;
import org.apache.hadoop.yarn.api.records.Resource;
import org.apache.hadoop.yarn.util.Records;

/**
 * <p>The response sent by the <code>ResourceManager</code> to a new 
 * <code>ApplicationMaster</code> on registration.</p>
 * 
 * <p>The response contains critical details such as:
 * <ul>
 *   <li>Maximum capability for allocated resources in the cluster.</li>
 *   <li><code>ApplicationACL</code>s for the application.</li>
 *   <li>ClientToAMToken master key.</li>
 * </ul>
 * </p>
 * 
 * @see ApplicationMasterProtocol#registerApplicationMaster(RegisterApplicationMasterRequest)
 */
@Public
@Stable
public abstract class RegisterApplicationMasterResponse {
  @Private
  @Unstable
  public static RegisterApplicationMasterResponse newInstance(
      Resource minCapability, Resource maxCapability,
      Map<ApplicationAccessType, String> acls, ByteBuffer key) {
    RegisterApplicationMasterResponse response =
        Records.newRecord(RegisterApplicationMasterResponse.class);
    response.setMaximumResourceCapability(maxCapability);
    response.setApplicationACLs(acls);
    response.setClientToAMTokenMasterKey(key);
    return response;
  }

  /**
   * Get the maximum capability for any {@link Resource} allocated by the 
   * <code>ResourceManager</code> in the cluster.
   * @return maximum capability of allocated resources in the cluster
   */
  @Public
  @Stable
  public abstract Resource getMaximumResourceCapability();
  
  @Private
  @Unstable
  public abstract void setMaximumResourceCapability(Resource capability);

  /**
   * Get the <code>ApplicationACL</code>s for the application. 
   * @return all the <code>ApplicationACL</code>s
   */
  @Public
  @Stable
  public abstract Map<ApplicationAccessType, String> getApplicationACLs();

  /**
   * Set the <code>ApplicationACL</code>s for the application. 
   * @param acls
   */
  @Private
  @Unstable
  public abstract void setApplicationACLs(Map<ApplicationAccessType, String> acls);

  /**
   * <p>Get ClientToAMToken master key.</p>
   * <p>The ClientToAMToken master key is sent to <code>ApplicationMaster</code>
   * by <code>ResourceManager</code> via {@link RegisterApplicationMasterResponse}
   * , used to verify corresponding ClientToAMToken.</p>
   */
  @Public
  @Stable
  public abstract ByteBuffer getClientToAMTokenMasterKey();

  /**
   * Set ClientToAMToken master key.
   */
  @Public
  @Stable
  public abstract void setClientToAMTokenMasterKey(ByteBuffer key);
}