/*
 * Copyright Terracotta, Inc.
 *
 * 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 org.ehcache.jsr107;

import java.io.Closeable;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicBoolean;

import javax.cache.configuration.CacheEntryListenerConfiguration;

import org.ehcache.jsr107.internal.Jsr107CacheLoaderWriter;

/**
 * @author teck
 */
class CacheResources<K, V> {

  private final Eh107Expiry<K, V> expiryPolicy;
  private final Jsr107CacheLoaderWriter<? super K, V> cacheLoaderWriter;
  private final Map<CacheEntryListenerConfiguration<K, V>, ListenerResources<K, V>> listenerResources = new ConcurrentHashMap<CacheEntryListenerConfiguration<K, V>, ListenerResources<K, V>>();
  private final AtomicBoolean closed = new AtomicBoolean();
  private final String cacheName;

  CacheResources(String cacheName, Jsr107CacheLoaderWriter<? super K, V> cacheLoaderWriter, Eh107Expiry<K, V> expiry, Map<CacheEntryListenerConfiguration<K, V>, ListenerResources<K, V>> listenerResources) {
    this.cacheName = cacheName;
    this.cacheLoaderWriter = cacheLoaderWriter;
    this.expiryPolicy = expiry;
    this.listenerResources.putAll(listenerResources);
  }

  CacheResources(String cacheName, Jsr107CacheLoaderWriter<? super K, V> cacheLoaderWriter, Eh107Expiry<K, V> expiry) {
    this(cacheName, cacheLoaderWriter, expiry, new ConcurrentHashMap<CacheEntryListenerConfiguration<K, V>, ListenerResources<K, V>>());
  }

  Eh107Expiry<K, V> getExpiryPolicy() {
    return expiryPolicy;
  }

  Jsr107CacheLoaderWriter<? super K, V> getCacheLoaderWriter() {
    return cacheLoaderWriter;
  }

  Map<CacheEntryListenerConfiguration<K, V>, ListenerResources<K, V>> getListenerResources() {
    return Collections.unmodifiableMap(listenerResources);
  }

  synchronized ListenerResources<K, V> registerCacheEntryListener(CacheEntryListenerConfiguration<K, V> listenerConfig) {
    checkClosed();

    if (listenerResources.containsKey(listenerConfig)) {
      throw new IllegalArgumentException("listener config already registered");
    }

    MultiCacheException mce = new MultiCacheException();
    ListenerResources<K, V> rv = ListenerResources.createListenerResources(listenerConfig, mce);
    mce.throwIfNotEmpty();
    listenerResources.put(listenerConfig, rv);
    return rv;
  }

  private void checkClosed() {
    if (closed.get()) {
      throw new IllegalStateException("cache resources closed for cache [" + cacheName + "]");
    }
  }

  synchronized ListenerResources<K, V> deregisterCacheEntryListener(CacheEntryListenerConfiguration<K, V> listenerConfig) {
    checkClosed();

    ListenerResources<K, V> resources = listenerResources.remove(listenerConfig);
    if (resources == null) {
      return null;
    }
    MultiCacheException mce = new MultiCacheException();
    close(resources, mce);
    mce.throwIfNotEmpty();
    return resources;
  }

  synchronized void closeResources(MultiCacheException mce) {
    if (closed.compareAndSet(false, true)) {
      close(expiryPolicy, mce);
      close(cacheLoaderWriter, mce);
      for (ListenerResources<K, V> lr : listenerResources.values()) {
        close(lr, mce);
      }
    }
  }

  boolean isClosed() {
    return closed.get();
  }

  static void close(Object obj, MultiCacheException mce) {
    if (obj instanceof Closeable) {
      try {
        ((Closeable) obj).close();
      } catch (Throwable t) {
        mce.addThrowable(t);
      }
    }
  }
}