package org.oddjob.scheduling;

import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A wrapper for {@link ThreadPoolExecutor} that provides an 
 * {@link #toString()} implementation.
 * 
 * @author rob
 *
 */
public class OddjobExecutorService implements ExecutorService {

	private final ThreadPoolExecutor delegate;

	/**
	 * Create a new instance.
	 * 
	 * @param delegate The executor to delegate all calls to.
	 */
	public OddjobExecutorService(ThreadPoolExecutor delegate) {
		this.delegate = delegate;
	}
	
	@Override
	public void execute(Runnable command) {
		delegate.execute(command);
	}

	@Override
	public void shutdown() {
		delegate.shutdown();
	}

	@Override
	public List<Runnable> shutdownNow() {
		return delegate.shutdownNow();
	}

	@Override
	public boolean isShutdown() {
		return delegate.isShutdown();
	}

	@Override
	public boolean isTerminated() {
		return delegate.isTerminated();
	}

	@Override
	public boolean awaitTermination(long timeout, TimeUnit unit)
			throws InterruptedException {
		return delegate.awaitTermination(timeout, unit);
	}

	@Override
	public <T> Future<T> submit(Callable<T> task) {
		return delegate.submit(task);
	}

	@Override
	public <T> Future<T> submit(Runnable task, T result) {
		return delegate.submit(task, result);
	}

	@Override
	public Future<?> submit(Runnable task) {
		return delegate.submit(task);
	}

	@Override
	public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
			throws InterruptedException {
		return delegate.invokeAll(tasks);
	}

	@Override
	public <T> List<Future<T>> invokeAll(
			Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
			throws InterruptedException {
		return delegate.invokeAll(tasks, timeout, unit);
	}

	@Override
	public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
			throws InterruptedException, ExecutionException {
		return delegate.invokeAny(tasks);
	}

	@Override
	public <T> T invokeAny(Collection<? extends Callable<T>> tasks,
			long timeout, TimeUnit unit) throws InterruptedException,
			ExecutionException, TimeoutException {
		return delegate.invokeAny(tasks, timeout, unit);
	}	
	
	@Override
	public String toString() {
		return getClass().getSimpleName() + ": active=" + 
				delegate.getActiveCount();
	}
}