/*
 * 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.samza.clustermanager;

import org.apache.samza.config.Config;

import java.lang.reflect.Field;
import java.util.Map;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

public class MockContainerAllocatorWithHostAffinity extends ContainerAllocator {
  private Semaphore semaphore = new Semaphore(0);

  public MockContainerAllocatorWithHostAffinity(ClusterResourceManager manager,
      Config config, SamzaApplicationState state, ContainerManager containerManager) {
    super(manager, config, state, true, containerManager);
  }

  /**
   * Causes the current thread to block until the expected number of containers have started.
   *
   * @param numExpectedContainers the number of containers expected to start
   * @param timeout the maximum time to wait
   * @param unit the time unit of the {@code timeout} argument
   *
   * @return a boolean that specifies whether containers started within the timeout.
   * @throws InterruptedException  if the current thread is interrupted while waiting
   */
  boolean awaitContainersStart(int numExpectedContainers, long timeout, TimeUnit unit) throws InterruptedException {
    return semaphore.tryAcquire(numExpectedContainers, timeout, unit);
  }

  @Override
  public void requestResources(Map<String, String> processorToHostMapping) {
    super.requestResources(processorToHostMapping);
  }

  public ResourceRequestState getContainerRequestState() throws Exception {
    Field field = ContainerAllocator.class.getDeclaredField("resourceRequestState");
    field.setAccessible(true);

    return (ResourceRequestState) field.get(this);
  }

  @Override
  protected void runStreamProcessor(SamzaResourceRequest request, String preferredHost) {
    super.runStreamProcessor(request, preferredHost);
    semaphore.release();
  }
}