/*
    * 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.hazelcast;
  
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.concurrent.TimeUnit;
  
  import com.hazelcast.core.HazelcastInstance;
  import com.hazelcast.cp.ISemaphore;
  import org.eclipse.aether.named.NamedLock;
  import org.eclipse.aether.named.NamedLockKey;
  import org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock;
  import org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock.AdaptedSemaphore;
  import org.eclipse.aether.named.support.NamedLockFactorySupport;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Factory of {@link AdaptedSemaphoreNamedLock} instances, using adapted Hazelcast {@link ISemaphore}. It delegates
   * most the work to {@link HazelcastSemaphoreProvider} and this class just adapts the returned semaphore to named lock
   * and caches {@link ISemaphore} instances, as recommended by Hazelcast.
   */
  public class HazelcastSemaphoreNamedLockFactory extends NamedLockFactorySupport {
      protected final HazelcastInstance hazelcastInstance;
  
      protected final boolean manageHazelcast;
  
      private final HazelcastSemaphoreProvider hazelcastSemaphoreProvider;
  
      private final ConcurrentMap<NamedLockKey, ISemaphore> semaphores;
  
      public HazelcastSemaphoreNamedLockFactory(
              final HazelcastInstance hazelcastInstance,
              final boolean manageHazelcast,
              final HazelcastSemaphoreProvider hazelcastSemaphoreProvider) {
          this.hazelcastInstance = requireNonNull(hazelcastInstance);
          this.manageHazelcast = manageHazelcast;
          this.hazelcastSemaphoreProvider = requireNonNull(hazelcastSemaphoreProvider);
          this.semaphores = new ConcurrentHashMap<>();
      }
  
      @Override
      protected AdaptedSemaphoreNamedLock createLock(final NamedLockKey key) {
          ISemaphore semaphore = semaphores.computeIfAbsent(
                  key, k -> hazelcastSemaphoreProvider.acquireSemaphore(hazelcastInstance, key));
          return new AdaptedSemaphoreNamedLock(key, this, new HazelcastSemaphore(semaphore));
      }
  
      @Override
      protected void destroyLock(final NamedLock namedLock) {
          if (namedLock instanceof AdaptedSemaphoreNamedLock) {
              final NamedLockKey key = namedLock.key();
              hazelcastSemaphoreProvider.releaseSemaphore(hazelcastInstance, key, semaphores.remove(key));
          }
      }
  
      @Override
      protected void doShutdown() {
          if (manageHazelcast) {
              hazelcastInstance.shutdown();
          }
      }
  
      private static final class HazelcastSemaphore implements AdaptedSemaphore {
          private final ISemaphore semaphore;
  
          private HazelcastSemaphore(final ISemaphore semaphore) {
              this.semaphore = semaphore;
          }
  
          @Override
          public boolean tryAcquire(final int perms, final long time, final TimeUnit unit) throws InterruptedException {
              return semaphore.tryAcquire(perms, time, unit);
          }
  
          @Override
          public void release(final int perms) {
              semaphore.release(perms);
          }
      }
  }