/*
    * 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
    *
    *      https://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.commons.pool2.impl;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.lang.reflect.Field;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.ThreadPoolExecutor;
  
  import org.apache.commons.pool2.BasePooledObjectFactory;
  import org.apache.commons.pool2.PooledObject;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests for {@link EvictionTimer}.
   */
  class TestEvictionTimer {
  
      @Test
      void testStartStopEvictionTimer() throws Exception {
  
          try (GenericObjectPool<String> pool = new GenericObjectPool<>(new BasePooledObjectFactory<String>() {
  
              @Override
              public String create() {
                  return null;
              }
  
              @Override
              public PooledObject<String> wrap(final String obj) {
                  return new DefaultPooledObject<>(obj);
              }
          })) {
  
              // Start evictor #1
              final BaseGenericObjectPool<String>.Evictor evictor1 = pool.new Evictor();
              EvictionTimer.schedule(evictor1, TestConstants.ONE_MINUTE_DURATION, TestConstants.ONE_MINUTE_DURATION);
  
              // Assert that eviction objects are correctly allocated
              // 1 - the evictor timer task is created
              final Field evictorTaskFutureField =
                      evictor1.getClass().getDeclaredField("scheduledFuture");
              evictorTaskFutureField.setAccessible(true);
              ScheduledFuture<?> sf = (ScheduledFuture<?>) evictorTaskFutureField.get(evictor1);
              assertFalse(sf.isCancelled());
              // 2- and, the eviction action is added to executor thread pool
              final Field evictorExecutorField = EvictionTimer.class.getDeclaredField("executor");
              evictorExecutorField.setAccessible(true);
              final ThreadPoolExecutor evictionExecutor = (ThreadPoolExecutor) evictorExecutorField.get(null);
              assertEquals(2, evictionExecutor.getQueue().size()); // Reaper plus one eviction task
              assertEquals(1, EvictionTimer.getNumTasks());
  
              // Start evictor #2
              final BaseGenericObjectPool<String>.Evictor evictor2 = pool.new Evictor();
              EvictionTimer.schedule(evictor2, TestConstants.ONE_MINUTE_DURATION, TestConstants.ONE_MINUTE_DURATION);
  
              // Assert that eviction objects are correctly allocated
              // 1 - the evictor timer task is created
              sf = (ScheduledFuture<?>) evictorTaskFutureField.get(evictor2);
              assertFalse(sf.isCancelled());
              // 2- and, the eviction action is added to executor thread pool
              assertEquals(3, evictionExecutor.getQueue().size()); // Reaper plus 2 eviction tasks
              assertEquals(2, EvictionTimer.getNumTasks());
  
              // Stop evictor #1
              EvictionTimer.cancel(evictor1, BaseObjectPoolConfig.DEFAULT_EVICTOR_SHUTDOWN_TIMEOUT, false);
  
              // Assert that eviction objects are correctly cleaned
              // 1 - the evictor timer task is canceled
              sf = (ScheduledFuture<?>) evictorTaskFutureField.get(evictor1);
              assertTrue(sf.isCancelled());
              // 2- and, the eviction action is removed from executor thread pool
              final ThreadPoolExecutor evictionExecutorOnStop = (ThreadPoolExecutor) evictorExecutorField.get(null);
              assertEquals(2, evictionExecutorOnStop.getQueue().size());
              assertEquals(1, EvictionTimer.getNumTasks());
  
              // Stop evictor #2
              EvictionTimer.cancel(evictor2, BaseObjectPoolConfig.DEFAULT_EVICTOR_SHUTDOWN_TIMEOUT, false);
  
              // Assert that eviction objects are correctly cleaned
              // 1 - the evictor timer task is canceled
             sf = (ScheduledFuture<?>) evictorTaskFutureField.get(evictor2);
             assertTrue(sf.isCancelled());
             // 2- and, the eviction thread pool executor is freed
             assertNull(evictorExecutorField.get(null));
             assertEquals(0, EvictionTimer.getNumTasks());
         }
     }
 }