package org.eclipse.aether.named.hazelcast;

/*
 * 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.
 */

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.eclipse.aether.named.NamedLock;
import org.eclipse.aether.named.NamedLockFactory;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TestName;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.Matchers.sameInstance;

/**
 * UT support for {@link NamedLockFactory}.
 */
public abstract class NamedLockFactoryTestSupport
{
    protected static final HazelcastClientUtils utils = new HazelcastClientUtils();

    protected static NamedLockFactory namedLockFactory;

    @Rule
    public TestName testName = new TestName();

    @AfterClass
    public static void cleanup()
    {
        if ( namedLockFactory != null )
        {
            namedLockFactory.shutdown();
        }
        utils.cleanup();
    }

    @Test
    public void refCounting()
    {
        final String name = testName.getMethodName();
        try ( NamedLock one = namedLockFactory.getLock( name );
              NamedLock two = namedLockFactory.getLock( name ) )
        {
            assertThat( one, sameInstance( two ) );
            one.close();
            two.close();

            try ( NamedLock three = namedLockFactory.getLock( name ) )
            {
                assertThat( three, not( sameInstance( two ) ) );
            }
        }
    }

    @Test( expected = IllegalStateException.class )
    public void unlockWoLock()
    {
        final String name = testName.getMethodName();
        try ( NamedLock one = namedLockFactory.getLock( name ) )
        {
            one.unlock();
        }
    }

    @Test
    public void wwBoxing() throws InterruptedException
    {
        final String name = testName.getMethodName();
        try ( NamedLock one = namedLockFactory.getLock( name ) )
        {
            assertThat( one.lockExclusively( 1L, TimeUnit.MILLISECONDS ), is( true ) );
            assertThat( one.lockExclusively( 1L, TimeUnit.MILLISECONDS ), is( true ) );
            one.unlock();
            one.unlock();
        }
    }

    @Test
    public void rrBoxing() throws InterruptedException
    {
        final String name = testName.getMethodName();
        try ( NamedLock one = namedLockFactory.getLock( name ) )
        {
            assertThat( one.lockShared( 1L, TimeUnit.MILLISECONDS ), is( true ) );
            assertThat( one.lockShared( 1L, TimeUnit.MILLISECONDS ), is( true ) );
            one.unlock();
            one.unlock();
        }
    }

    @Test
    public void wrBoxing() throws InterruptedException
    {
        final String name = testName.getMethodName();
        try ( NamedLock one = namedLockFactory.getLock( name ) )
        {
            assertThat( one.lockExclusively( 1L, TimeUnit.MILLISECONDS ), is( true ) );
            assertThat( one.lockShared( 1L, TimeUnit.MILLISECONDS ), is( true ) );
            one.unlock();
            one.unlock();
        }
    }

    @Test
    public void rwBoxing() throws InterruptedException
    {
        final String name = testName.getMethodName();
        try ( NamedLock one = namedLockFactory.getLock( name ) )
        {
            assertThat( one.lockShared( 1L, TimeUnit.MILLISECONDS ), is( true ) );
            assertThat( one.lockExclusively( 1L, TimeUnit.MILLISECONDS ), is( false ) );
            one.unlock();
        }
    }

    @Test( timeout = 5000 )
    public void sharedAccess() throws InterruptedException
    {
        final String name = testName.getMethodName();
        CountDownLatch winners = new CountDownLatch( 2 ); // we expect 2 winner
        CountDownLatch losers = new CountDownLatch( 0 ); // we expect 0 loser
        Thread t1 = new Thread( new Access( namedLockFactory, name, true, winners, losers ) );
        Thread t2 = new Thread( new Access( namedLockFactory, name, true, winners, losers ) );
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        winners.await();
        losers.await();
    }

    @Test( timeout = 5000 )
    public void exclusiveAccess() throws InterruptedException
    {
        final String name = testName.getMethodName();
        CountDownLatch winners = new CountDownLatch( 1 ); // we expect 1 winner
        CountDownLatch losers = new CountDownLatch( 1 ); // we expect 1 loser
        Thread t1 = new Thread( new Access( namedLockFactory, name, false, winners, losers ) );
        Thread t2 = new Thread( new Access( namedLockFactory, name, false, winners, losers ) );
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        winners.await();
        losers.await();
    }

    @Test( timeout = 5000 )
    public void mixedAccess() throws InterruptedException
    {
        final String name = testName.getMethodName();
        CountDownLatch winners = new CountDownLatch( 1 ); // we expect 1 winner
        CountDownLatch losers = new CountDownLatch( 1 ); // we expect 1 loser
        Thread t1 = new Thread( new Access( namedLockFactory, name, true, winners, losers ) );
        Thread t2 = new Thread( new Access( namedLockFactory, name, false, winners, losers ) );
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        winners.await();
        losers.await();
    }

    private static class Access implements Runnable
    {
        final NamedLockFactory namedLockFactory;
        final String name;
        final boolean shared;
        final CountDownLatch winner;
        final CountDownLatch loser;

        public Access( NamedLockFactory namedLockFactory,
                       String name,
                       boolean shared,
                       CountDownLatch winner,
                       CountDownLatch loser )
        {
            this.namedLockFactory = namedLockFactory;
            this.name = name;
            this.shared = shared;
            this.winner = winner;
            this.loser = loser;
        }

        @Override
        public void run()
        {
            try ( NamedLock lock = namedLockFactory.getLock( name ) )
            {
                if ( shared ? lock.lockShared( 100L, TimeUnit.MILLISECONDS ) :
                        lock.lockExclusively( 100L, TimeUnit.MILLISECONDS ) )
                {
                    try
                    {
                        winner.countDown();
                        loser.await();
                    }
                    finally
                    {
                        lock.unlock();
                    }
                }
                else
                {
                    loser.countDown();
                    winner.await();
                }
            }
            catch ( InterruptedException e )
            {
                Assert.fail( e.getMessage() );
            }
        }
    }
}