/**
    * This file Copyright (c) 2008-2015 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.module.cache.ehcache;
  
  import info.magnolia.cms.core.Path;
  import info.magnolia.cms.util.DeprecationUtil;
  import info.magnolia.cms.util.MBeanUtil;
  import info.magnolia.init.MagnoliaInitPaths;
  import info.magnolia.module.cache.Cache;
  import info.magnolia.module.cache.CacheFactory;
  import info.magnolia.module.cache.CacheModule;
  import info.magnolia.module.cache.mbean.CacheMonitor;
  import info.magnolia.objectfactory.Components;
  
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import javax.inject.Inject;
  import javax.management.MBeanServer;
  
  import org.apache.commons.lang3.StringUtils;
  
  import net.sf.ehcache.CacheManager;
  import net.sf.ehcache.Ehcache;
  import net.sf.ehcache.config.Configuration;
  import net.sf.ehcache.config.DiskStoreConfiguration;
  import net.sf.ehcache.config.generator.ConfigurationSource;
  import net.sf.ehcache.constructs.blocking.BlockingCache;
  import net.sf.ehcache.management.ManagementService;
  
  /**
   * A CacheFactory based on ehcache and which wraps BlockingCache instances.
   */
  public class EhCacheFactory implements CacheFactory {
      private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(EhCacheFactory.class);
  
      private final CacheMonitor cacheMonitor;
  
      private CacheManager cacheManager;
      private CacheModule cacheModule;
      private MagnoliaInitPaths magnoliaInitPaths;
      private Map<String, EhCacheConfiguration> caches = new HashMap<String, EhCacheConfiguration>();
      private String diskStorePath;
      // 0 == do not timeout ever, set to 10s by default.
      private int blockingTimeout = 10000;
  
      @Inject
      public EhCacheFactory(CacheMonitor cacheMonitor, CacheModule cacheModule, MagnoliaInitPaths magnoliaInitPaths) {
          this.cacheMonitor = cacheMonitor;
          this.cacheModule = cacheModule;
          this.magnoliaInitPaths = magnoliaInitPaths;
          diskStorePath = Path.getCacheDirectoryPath();
      }
  
      /**
       * @deprecated since 5.4. Use {@link #EhCacheFactory(info.magnolia.module.cache.mbean.CacheMonitor, info.magnolia.module.cache.CacheModule, info.magnolia.init.MagnoliaInitPaths)} instead.
       */
      public EhCacheFactory(CacheMonitor cacheMonitor) {
          this(cacheMonitor, Components.getComponent(CacheModule.class), Components.getComponent(MagnoliaInitPaths.class));
      }
  
      @Deprecated
      public EhCacheConfiguration getDefaultCacheConfiguration() {
          DeprecationUtil.isDeprecated("Code should not be calling info.magnolia.module.cache.ehcache.EhCacheFactory#getDefaultCacheConfiguration");
          return getCaches().get(DEFAULT_CACHE_NAME);
      }
 
     // There is no absolute guarantee that the caches Map will be populated before Node2Bean calls setDefaultCacheConfiguration(), but we know that's how it behaves (populates subnodes first)
     @Deprecated
     public void setDefaultCacheConfiguration(EhCacheConfiguration defaultCacheConfiguration) {
         if (!isDefaultCacheName(defaultCacheConfiguration.getName())) {
             log.warn("Calling setDefaultCacheConfiguration with a CacheConfiguration of name " + defaultCacheConfiguration.getName() + "; it should be unnamed.");
         }
         if (!getCaches().containsKey(DEFAULT_CACHE_NAME)) {
             DeprecationUtil.isDeprecated("Configure your default cache settings under modules/cache/configuration/cacheFactory/caches/default rather than modules/cache/configuration/cacheFactory/defaultCacheConfiguration");
             getCaches().put(DEFAULT_CACHE_NAME, defaultCacheConfiguration);
         } else {
             log.warn("You already have a configuration at modules/cache/configuration/cacheFactory/caches/default, ignoring modules/cache/configuration/cacheFactory/defaultCacheConfiguration");
         }
     }
 
     /**
      * These are cache configurations. We call this method getCaches() to make it nicer to configure than if it was called getCacheConfigurations().
      */
     public Map<String, EhCacheConfiguration> getCaches() {
         return caches;
     }
 
     public void setCaches(Map<String, EhCacheConfiguration> caches) {
         this.caches = caches;
     }
 
     public String getDiskStorePath() {
         return diskStorePath;
     }
 
     public void setDiskStorePath(String diskStorePath) {
         this.diskStorePath = diskStorePath;
     }
 
     public int getBlockingTimeout() {
         return blockingTimeout;
     }
 
     public void setBlockingTimeout(int blockingTimeout) {
         this.blockingTimeout = blockingTimeout;
     }
 
     /**
      * Caches currently known by the underlying CacheManager (which includes all configured caches as well as those created on-demand based on the default config).
      */
     @Override
     public List getCacheNames() {
         return Arrays.asList(cacheManager.getCacheNames());
     }
 
     @Override
     public Cache getCache(String name) {
         if (isDefaultCacheName(name)) {
             throw new IllegalArgumentException("'" + name + "' is not a valid cache name.");
         }
         Ehcache ehcache = cacheManager.getEhcache(name);
 
         // cacheManager will return null if there is no explicit cache configuration for this name
         if (ehcache == null) {
             // then we need to explicitly create/register it
             createCache(name);
             return getCache(name);
         }
         // cacheManager will return a non-wrapped instance of Ehcache if there is an explicit configuration with this name
         // Recent versions of EhCache introduced a CacheDecoratorFactory, but that would imply configuring this for every cache, it forces an empty constructor and passes Properties around to the decorate() method. Not very elegant.
         if (!(ehcache instanceof BlockingCache)) {
             ehcache = decorateAndSubstitute(ehcache);
         }
         return wrap(name, ehcache);
     }
 
     // Adds a cache to the cacheManager, which is somehow able to retrieve items previously stored
     protected void createCache(String name) {
         synchronized (this.getClass()) {
             cacheManager.addCache(name);
         }
     }
 
     protected BlockingCache decorateAndSubstitute(Ehcache ehcache) {
         synchronized (this.getClass()) {
             BlockingCache newBlockingCache = new BlockingCache(ehcache);
             newBlockingCache.setTimeoutMillis(getBlockingTimeout());
             cacheManager.replaceCacheWithDecoratedCache(ehcache, newBlockingCache);
             return newBlockingCache;
         }
     }
 
     protected EhCacheWrapper wrap(String name, Ehcache ehcache) {
         return new EhCacheWrapper(cacheModule, ehcache, cacheMonitor, name);
     }
 
     private boolean isDefaultCacheName(String name) {
         return DEFAULT_CACHE_NAME.equals(name) || name == null;
     }
 
     @Override
     public void start(boolean isRestart) {
         final Configuration cfg = new Configuration();
 
         // This methods gets called whenever the module's config changes, so this is fine - TODO we just need to double what happens with existing cache/cacheManager
         for (EhCacheConfiguration cacheConfig : caches.values()) {
             // skip "default", which is not an actual cache but just a "template" config.
             if (!isDefaultCacheName(cacheConfig.getName())) {
                 cfg.addCache(cacheConfig);
             }
         }
 
         EhCacheConfiguration defaultCacheConfiguration = caches.get(DEFAULT_CACHE_NAME);
         if (defaultCacheConfiguration != null) {
             // The defaultCacheConfiguration should not have a name (it has one here, as a side-effect of node2bean auto-calling the setName method with a node's name)
             defaultCacheConfiguration.resetName();
         } else {
             log.warn("Default cache configuration is not set.");
             defaultCacheConfiguration = new EhCacheConfiguration();
             defaultCacheConfiguration.setMaxEntriesLocalHeap(10000);
         }
         cfg.setDefaultCacheConfiguration(defaultCacheConfiguration);
 
 
         if (!caches.isEmpty()) {
             cfg.setSource(new DescribingConfigurationSource("Magnolia-based cache configuration"));
         }
         if (diskStorePath != null) {
             cfg.diskStore(new DiskStoreConfiguration().path(diskStorePath));
             cfg.setSource(new DescribingConfigurationSource("Magnolia-based diskStorePath"));
         }
         cfg.setName(this.getCacheManagerIdentifier());
         cacheManager = CacheManager.getCacheManager(cfg.getName());
         if (cacheManager == null) { //module start
             cacheManager = new CacheManager(cfg);
             final MBeanServer mBeanServer = MBeanUtil.getMBeanServer();
             ManagementService.registerMBeans(cacheManager, mBeanServer, true, true, true, true, false);
         }
     }
 
     private String getCacheManagerIdentifier() {
         return StringUtils.removeStart(magnoliaInitPaths.getContextPath(), "/") + "#" + getClass().getName() + "#cacheManager";
     }
 
     @Override
     public void stop(boolean isRestart) {
         if (!isRestart) {
             cacheManager.shutdown();
         }
     }
 
     public CacheManager getWrappedCacheManager() {
         return cacheManager;
     }
 
     private static final class DescribingConfigurationSource extends ConfigurationSource {
         private final String description;
 
         private DescribingConfigurationSource(String description) {
             this.description = description;
         }
 
         @Override
         public Configuration createConfiguration() {
             throw new IllegalStateException("not implemented - not needed");
         }
 
         @Override
         public String toString() {
             return description;
         }
     }
 }