/*
 * Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
 *
 * 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.hazelcast.concurrent.countdownlatch;

import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.core.HazelcastInstanceNotActiveException;
import com.hazelcast.core.ICountDownLatch;
import com.hazelcast.spi.exception.DistributedObjectDestroyedException;
import com.hazelcast.spi.impl.NodeEngineImpl;
import com.hazelcast.test.HazelcastParallelClassRunner;
import com.hazelcast.test.HazelcastTestSupport;
import com.hazelcast.test.TestHazelcastInstanceFactory;
import com.hazelcast.test.TestThread;
import com.hazelcast.test.annotation.ParallelTest;
import com.hazelcast.test.annotation.QuickTest;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;

import java.util.concurrent.TimeUnit;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

@RunWith(HazelcastParallelClassRunner.class)
@Category({QuickTest.class, ParallelTest.class})
public class CountDownLatchAdvancedTest extends HazelcastTestSupport {

    @Test
    public void testCountDown_whenReachZero_thenLatchRemoved() {
        HazelcastInstance instance = createHazelcastInstance();
        ICountDownLatch latch = instance.getCountDownLatch(randomString());
        CountDownLatchService service = getNode(instance).getNodeEngine().getService(CountDownLatchService.SERVICE_NAME);

        latch.trySetCount(1);
        assertTrue(service.containsLatch(latch.getName()));
        latch.countDown();
        assertFalse(service.containsLatch(latch.getName()));
    }

    @Test
    public void testDestroy() {
        HazelcastInstance instance = createHazelcastInstance();
        ICountDownLatch latch = instance.getCountDownLatch(randomString());
        NodeEngineImpl nodeEngine = getNode(instance).getNodeEngine();
        CountDownLatchService service = nodeEngine.getService(CountDownLatchService.SERVICE_NAME);

        latch.destroy();
        assertFalse(service.containsLatch(latch.getName()));
    }

    @Test
    public void testAwait_whenInstanceShutdown_thenHazelcastInstanceNotActiveException() throws InterruptedException {
        HazelcastInstance instance = createHazelcastInstance();
        final ICountDownLatch latch = instance.getCountDownLatch(randomString());
        latch.trySetCount(10);

        final TestThread awaitThread = new TestThread() {
            @Override
            public void doRun() throws Exception {
                latch.await(1, TimeUnit.HOURS);
            }
        };
        awaitThread.start();

        // give the awaitthread some time to get in the waiting state
        sleepSeconds(5);
        instance.shutdown();
        awaitThread.assertFailsEventually(HazelcastInstanceNotActiveException.class);
    }

    @Test
    public void testSimpleUsage() throws InterruptedException {
        final int k = 5;
        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory(k);
        final HazelcastInstance[] instances = factory.newInstances();
        ICountDownLatch latch = instances[0].getCountDownLatch("test");
        latch.trySetCount(k - 1);
        assertEquals(k - 1, latch.getCount());

        new Thread() {
            public void run() {
                for (int i = 1; i < k; i++) {
                    try {
                        sleep(100);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    final ICountDownLatch l = instances[i].getCountDownLatch("test");
                    l.countDown();
                    assertEquals(k - 1 - i, l.getCount());
                }
            }
        }.start();

        assertTrue(latch.await(5000, TimeUnit.MILLISECONDS));
        assertEquals(0, latch.getCount());
    }

    @Test(expected = DistributedObjectDestroyedException.class)
    public void testLatchDestroyed() throws Exception {
        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory(2);
        HazelcastInstance hz1 = factory.newHazelcastInstance();
        HazelcastInstance hz2 = factory.newHazelcastInstance();
        final ICountDownLatch latch = hz1.getCountDownLatch("test");
        latch.trySetCount(2);

        new TestThread() {
            public void doRun() throws Exception {
                sleep(1000);
                latch.destroy();
            }
        }.start();

        hz2.getCountDownLatch("test").await(5, TimeUnit.SECONDS);
    }

}