/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.bgpcep.programming.impl;

import com.google.common.collect.Lists;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;

import java.util.List;
import java.util.concurrent.Callable;

import static org.junit.Assert.assertEquals;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;

final class MockedExecutorWrapper {

	private List<Object> submittedTasksToExecutor;

	MockedExecutorWrapper() {
		submittedTasksToExecutor = Lists.newArrayList();
	}

	ListeningExecutorService getMockedExecutor() {
		ListeningExecutorService mockedExecutor = mock(ListeningExecutorService.class);
		Answer<ListenableFuture<?>> submitAnswer = new Answer<ListenableFuture<?>>() {
			@Override
			public ListenableFuture<?> answer(InvocationOnMock invocation) throws Throwable {
				Object task = invocation.getArguments()[0];
				submittedTasksToExecutor.add(task);

				Object result = null;
				if(task instanceof Runnable) {
					((Runnable)task).run();
				} else if(task instanceof Callable) {
					result = ((Callable<?>)task).call();
				}

				ListenableFuture<?> mockedFuture = mock(ListenableFuture.class);
				doReturn(result).when(mockedFuture).get();
				return mockedFuture;
			}
		};
		doAnswer(submitAnswer).when(mockedExecutor).submit(any(Runnable.class));
		doAnswer(submitAnswer).when(mockedExecutor).submit(any(Callable.class));
		return mockedExecutor;
	}

	void assertSubmittedTasksSize(int taskCount) {
		assertEquals(taskCount, submittedTasksToExecutor.size());
	}
}