/*
    * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.spi.config.cache.infinispan;
  
  import java.util.HashSet;
  import java.util.Set;
  import java.util.concurrent.locks.Lock;
  import java.util.concurrent.locks.ReentrantReadWriteLock;
  
  import org.infinispan.configuration.cache.Configuration;
  import org.infinispan.manager.EmbeddedCacheManager;
  
  import de.smartics.properties.spi.config.cache.Cache;
  import de.smartics.properties.spi.config.cache.CacheManager;
  import de.smartics.properties.spi.config.cache.UnawareCache;
  import de.smartics.properties.spi.config.cache.guava.GuavaCacheManager;
  import de.smartics.util.lang.StaticAnalysis;
  
  /**
   * The base implementation to connect to Infinispan caches.
   */
  public abstract class AbstractInfinispanCompoundKeyCacheManager implements
      CacheManager
  { // NOPMD
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The name for the cache.
     */
    private static final String CACHE_NAME = "smartics-properties-cache";
  
    // --- members --------------------------------------------------------------
  
    /**
     * The lock for synchronized access.
     *
     * @serial
     */
    private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
  
    /**
     * The read lock for synchronized access.
     *
     * @serial
     */
    private final Lock readLock = lock.readLock();
  
    /**
     * The write lock for synchronized access.
     *
     * @serial
     */
    private final Lock writeLock = lock.writeLock();
  
    /**
     * The infinispan cache manager for property keys.
     */
    @SuppressWarnings("unused")
    private final EmbeddedCacheManager manager; // NOPMD
  
    /**
     * The in memory cache manager for configurations / management.
     */
    private final GuavaCacheManager configManager;
  
    /**
     * The underlaying cache.
     */
    private final org.infinispan.Cache<Object, Object> cache;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param manager the Infinispan cache manager.
     */
    public AbstractInfinispanCompoundKeyCacheManager(
        final EmbeddedCacheManager manager)
    {
      this.manager = manager;
      configManager = new GuavaCacheManager();
 
     manager.getDefaultCacheConfiguration().jmxStatistics();
 
     this.cache = manager.getCache(CACHE_NAME);
     if (!manager.isRunning(CACHE_NAME))
     {
       final Configuration cacheConfig = this.cache.getCacheConfiguration();
       cacheConfig.jmxStatistics();
       cacheConfig.indexing().indexLocalOnly();
       cache.start();
     }
     // cache.addListener(new CompoundKeyHandlingCacheListener());
     cache.clear();
   }
 
   // ****************************** Inner Classes *****************************
 
   // ********************************* Methods ********************************
 
   // --- init -----------------------------------------------------------------
 
   // --- get&set --------------------------------------------------------------
 
   // --- business -------------------------------------------------------------
 
   /**
    * Removes all keys from all caches.
    */
   @Override
   public final void clearAll()
   {
     writeLock.lock();
     try
     {
       internalClearAll();
     }
     finally
     {
       writeLock.unlock();
     }
   }
 
   /**
    * Clears the cache with the given name.
    *
    * @param cacheName the name of the cache to be cleared.
    */
   @Override
   public final void clear(final String cacheName)
   {
     writeLock.lock();
     try
     {
       internalClear(cacheName);
     }
     finally
     {
       writeLock.unlock();
     }
   }
 
   /**
    * Clears and stops the cache.
    *
    * @param cacheName the name of the cache to be cleared and stopped.
    */
   @Override
   public final void discard(final String cacheName)
   {
     writeLock.lock();
     try
     {
       if (isManagementCache(cacheName))
       {
         configManager.discard(cacheName);
       }
       internalClear(cacheName);
       internalStop(cacheName);
     }
     finally
     {
       writeLock.unlock();
     }
 
   }
 
   /**
    * Stops all caches, rendering the manager in a stopped state.
    */
   @Override
   public final void stopAll()
   {
     writeLock.lock();
     try
     {
       internalStopAll();
     }
     finally
     {
       writeLock.unlock();
     }
   }
 
   /**
    * Stops the cache with the given name.
    *
    * @param cacheName the name of the cache to stop.
    */
   @Override
   public final void stop(final String cacheName)
   {
     writeLock.lock();
     try
     {
       internalStop(cacheName);
     }
     finally
     {
       writeLock.unlock();
     }
   }
 
   /**
    * Returns the properties cache with the given name. The cache is already
    * started.
    *
    * @param cacheName the name of the cache to fetch.
    * @return the requested cache already started.
    */
   @SuppressWarnings({ StaticAnalysis.RAWTYPES, StaticAnalysis.UNCHECKED })
   public final UnawareCache getPropertiesCache(final String cacheName)
   {
     writeLock.lock();
     try
     {
       final UnawareCache propertiesCache =
           internalGetPropertiesCache(cacheName);
       return propertiesCache;
     }
     finally
     {
       writeLock.unlock();
     }
   }
 
   /**
    * Returns the configurations cache with the given name. The cache is already
    * started.
    *
    * @param cacheName the name of the cache to fetch.
    * @return the requested cache already started.
    */
   @SuppressWarnings({ StaticAnalysis.RAWTYPES, StaticAnalysis.UNCHECKED })
   public final Cache getConfigurationsCache(final String cacheName)
   {
     writeLock.lock();
     try
     {
       return configManager.getConfigurationsCache(cacheName);
     }
     finally
     {
       writeLock.unlock();
     }
   }
 
   /**
    * Returns the set of cache names.
    *
    * @return the set of cache names.
    */
   @SuppressWarnings({ StaticAnalysis.RAWTYPES, StaticAnalysis.UNCHECKED })
   @Override
   public final Set<String> getCacheNames()
   {
     readLock.lock();
     try
     {
       final Cache infinispanDelegatingCacheCache =
           configManager.getInfinispanDelegatingCache();
       final Set<String> cacheNames = infinispanDelegatingCacheCache.keySet();
 
       final HashSet allCacheNames = new HashSet<String>();
       if (cacheNames != null)
       {
         allCacheNames.addAll(cacheNames);
       }
       final Set inMemoryCacheNames = configManager.getCacheNames();
       if (inMemoryCacheNames != null)
       {
         allCacheNames.addAll(inMemoryCacheNames);
       }
       return allCacheNames;
     }
     finally
     {
       readLock.unlock();
     }
   }
 
   // --- private -------------------------------------------------------------
 
   /**
    * Removes all keys from all caches.
    */
   private void internalClearAll()
   {
     configManager.clearAll();
     cache.clear();
   }
 
   /**
    * Clears the cache with the given name.
    *
    * @param cacheName the name of the cache to be cleared.
    */
   private void internalClear(final String cacheName)
   {
     if (isManagementCache(cacheName))
     {
       configManager.clear(cacheName);
     }
     else if (isInfinispanDelegatingCache(cacheName))
     {
       internalClearAll();
     }
     else
     {
       // TODO TK clear only the properties for this cache
       cache.clear();
     }
   }
 
   private boolean isInfinispanDelegatingCache(final String cacheName)
   {
     return GuavaCacheManager.INFINISPAN_DELEGATING_CACHE_CACHE_NAME
         .equals(cacheName);
   }
 
   private boolean isManagementCache(final String cacheName)
   {
     return cacheName.startsWith("Management");
   }
 
   /**
    * Stops all caches, rendering the manager in a stopped state.
    */
   private void internalStopAll()
   {
     configManager.stopAll();
     cache.stop();
   }
 
   /**
    * Stops the cache with the given name.
    *
    * @param cacheName the name of the cache to stop.
    */
   private void internalStop(final String cacheName)
   {
     if (isManagementCache(cacheName))
     {
       configManager.stop(cacheName);
     }
   }
 
   /**
    * Returns the properties cache with the given name. The cache is already
    * started.
    *
    * @param cacheName the name of the cache to fetch.
    * @return the requested cache already started.
    */
   @SuppressWarnings({ StaticAnalysis.RAWTYPES, StaticAnalysis.UNCHECKED })
   private UnawareCache<?, ?> internalGetPropertiesCache(final String cacheName)
   {
     final Cache infinispanCacheCache =
         configManager.getInfinispanDelegatingCache();
     InfinispanCompoundKeyDelegatingCache infinispanCache =
         (InfinispanCompoundKeyDelegatingCache) infinispanCacheCache
             .get(cacheName);
 
     if (infinispanCache == null)
     {
       infinispanCache =
           new InfinispanCompoundKeyDelegatingCache(cacheName, this.cache);
       infinispanCacheCache.put(cacheName, infinispanCache);
     }
     return infinispanCache;
   }
 
   // --- object basics --------------------------------------------------------
 
 }