/*
    * 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.
   */
  package org.eclipse.aether.named;
  
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.TimeUnit;
  
  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.*;
  
  /**
   * UT support for {@link NamedLockFactory}.
   */
  public abstract class NamedLockFactoryTestSupport {
  
      protected static NamedLockFactory namedLockFactory;
  
      @Rule
      public TestName testName = new TestName();
  
      protected String lockName() {
          return testName.getMethodName();
      }
  
      @Test
      public void refCounting() {
          final String name = lockName();
          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 = lockName();
          try (NamedLock one = namedLockFactory.getLock(name)) {
              one.unlock();
          }
      }
  
      @Test
      public void wwBoxing() throws InterruptedException {
          final String name = lockName();
          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 = lockName();
          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 = lockName();
          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 = lockName();
         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 = lockName();
         CountDownLatch winners = new CountDownLatch(2); // we expect 2 winners
         CountDownLatch losers = new CountDownLatch(0); // we expect 0 losers
         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 = lockName();
         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 = lockName();
         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();
     }
 
     @Test(timeout = 5000)
     public void fullyConsumeLockTime() throws InterruptedException {
         long start = System.nanoTime();
         final String name = lockName();
         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();
         long end = System.nanoTime();
         long duration = end - start;
         long expectedDuration = TimeUnit.MILLISECONDS.toNanos(ACCESS_WAIT_MILLIS);
         assertThat(duration, greaterThanOrEqualTo(expectedDuration)); // equal in ideal case
     }
 
     @Test(timeout = 5000)
     public void releasedExclusiveAllowAccess() throws InterruptedException {
         final String name = lockName();
         CountDownLatch winners = new CountDownLatch(1); // we expect 1 winner
         CountDownLatch losers = new CountDownLatch(0); // we expect 0 loser
         Thread t1 = new Thread(new Access(namedLockFactory, name, true, winners, losers));
         try (NamedLock namedLock = namedLockFactory.getLock(name)) {
             assertThat(namedLock.lockExclusively(50L, TimeUnit.MILLISECONDS), is(true));
             try {
                 t1.start();
                 Thread.sleep(50L);
             } finally {
                 namedLock.unlock();
             }
         }
         t1.join();
         winners.await();
         losers.await();
     }
 
     private static final long ACCESS_WAIT_MILLIS = 1000L;
 
     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(ACCESS_WAIT_MILLIS, TimeUnit.MILLISECONDS)
                         : lock.lockExclusively(ACCESS_WAIT_MILLIS, TimeUnit.MILLISECONDS)) {
                     try {
                         winner.countDown();
                         loser.await();
                     } finally {
                         lock.unlock();
                     }
                 } else {
                     loser.countDown();
                     winner.await();
                 }
             } catch (InterruptedException e) {
                 Assert.fail(e.getMessage());
             }
         }
     }
 }