/*
 * Copyright (C) 2013 The Guava Authors
 *
 * Licensed 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 com.google.common.util.concurrent;

import com.google.common.annotations.GwtIncompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.Callable;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *
 * <p>Note that task wrapping may occur even if the task is never executed.
 *
 * @author Luke Sandberg
 */
@CanIgnoreReturnValue // TODO(cpovirk): Consider being more strict.
@GwtIncompatible
@ElementTypesAreNonnullByDefault
abstract class WrappingScheduledExecutorService extends WrappingExecutorService
    implements ScheduledExecutorService {
  final ScheduledExecutorService delegate;

  protected WrappingScheduledExecutorService(ScheduledExecutorService delegate) {
    super(delegate);
    this.delegate = delegate;
  }

  @Override
  public final ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
    return delegate.schedule(wrapTask(command), delay, unit);
  }

  @Override
  public final <V extends @Nullable Object> ScheduledFuture<V> schedule(
      Callable<V> task, long delay, TimeUnit unit) {
    return delegate.schedule(wrapTask(task), delay, unit);
  }

  @Override
  public final ScheduledFuture<?> scheduleAtFixedRate(
      Runnable command, long initialDelay, long period, TimeUnit unit) {
    return delegate.scheduleAtFixedRate(wrapTask(command), initialDelay, period, unit);
  }

  @Override
  public final ScheduledFuture<?> scheduleWithFixedDelay(
      Runnable command, long initialDelay, long delay, TimeUnit unit) {
    return delegate.scheduleWithFixedDelay(wrapTask(command), initialDelay, delay, unit);
  }
}