/*
 * 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.beam.runners.flink.translation.utils;

import com.fasterxml.jackson.databind.type.TypeFactory;
import java.lang.reflect.Field;
import org.apache.beam.runners.core.TimerInternals;
import org.apache.flink.runtime.state.InternalPriorityQueue;
import org.apache.flink.streaming.api.operators.InternalTimer;
import org.apache.flink.streaming.api.operators.InternalTimerService;
import org.apache.flink.streaming.api.operators.InternalTimerServiceImpl;

/** Workarounds for dealing with limitations of Flink or its libraries. */
public class Workarounds {

  public static void deleteStaticCaches() {
    // Clear cache to get rid of any references to the Flink Classloader
    // See https://jira.apache.org/jira/browse/BEAM-6460
    TypeFactory.defaultInstance().clearCache();
  }

  @SuppressWarnings("all")
  public static InternalPriorityQueue<InternalTimer<Object, TimerInternals.TimerData>>
      retrieveInternalProcessingTimerQueue(
          InternalTimerService<TimerInternals.TimerData> timerService) {
    Field internalProcessingTimerQueue = null;
    try {
      internalProcessingTimerQueue =
          InternalTimerServiceImpl.class.getDeclaredField("processingTimeTimersQueue");
      internalProcessingTimerQueue.setAccessible(true);
      return (InternalPriorityQueue) internalProcessingTimerQueue.get(timerService);
    } catch (Exception e) {
      throw new IllegalStateException("Failed to retrieve processing timer queue.", e);
    } finally {
      if (internalProcessingTimerQueue != null) {
        internalProcessingTimerQueue.setAccessible(false);
      }
    }
  }
}
