package org.jtheque.core.managers.cache;

 import net.sf.ehcache.Cache;

 import net.sf.ehcache.store.MemoryStoreEvictionPolicy;

 import org.jtheque.core.managers.AbstractActivableManager;

 import org.jtheque.core.managers.Managers;

 import org.jtheque.core.managers.log.ILoggingManager;

 import java.io.File;

 import java.lang.reflect.Field;

 /*

  * This file is part of JTheque.

  *

  * JTheque is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, either version 3 of the License.

  *

  * JTheque is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with JTheque.  If not, see <http://www.gnu.org/licenses/>.

  */

 /**

  * A cache manager implementation.

  *

  * @author Baptiste Wicht

  */

 public final class CacheManager extends AbstractActivableManager implements ICacheManager {

     private static final int TWO_MINUTES = 120;

     @Override

     public void preInit() {

         net.sf.ehcache.CacheManager manager = net.sf.ehcache.CacheManager.create();

         setDiskStorePath(manager, Managers.getCore().getFolders().getCacheFolder());

     }

     @Override

     public void close(){

         getCacheManager().shutdown();

     }

     /**

      * Return the EhCache CacheManager instance.

      *

      * @return The EhCache CacheManager instance.

      */

     private static net.sf.ehcache.CacheManager getCacheManager() {

         return net.sf.ehcache.CacheManager.getInstance();

     }

     @Override

     public void addCache(CacheConfiguration config) {

         Cache cache = new Cache(

                 config.getName(),

                 config.getMaxElementsInMemory(),

                 MemoryStoreEvictionPolicy.LFU,

                 config.isOverflowToDisk(),

                 Managers.getCore().getFolders().getCacheFolder().getAbsolutePath(),

                 config.isEternal(),

                 config.getTimeToLiveSeconds(),

                 config.getTimeToIdleSeconds(),

                 config.isDiskPersistent(),

                 TWO_MINUTES,

                 null,

                 null,

                 config.getMaxElementsOnDisk(),

                 20

         );

         getCacheManager().addCache(cache);

     }

     @Override

     public Cache getCache(String name) {

         return getCacheManager().getCache(name);

     }

     @Override

     public boolean cacheExists(String name) {

         return getCacheManager().cacheExists(name);

     }

     @Override

     public void removeCache(String name) {

         getCacheManager().removeCache(name);

     }

     /**

      * Set the disk store path of the caches by reflection.

      *

      * @param manager     The manager to configure.

      * @param cacheFolder The folder of the caches.

      */

     private void setDiskStorePath(Object manager, File cacheFolder) {

         try {

             Field m = manager.getClass().getDeclaredField("diskStorePath");

             m.setAccessible(true);

             m.set(manager, cacheFolder.getAbsolutePath());

         } catch (Exception e) {

             Managers.getManager(ILoggingManager.class).getLogger(getClass()).error(e, "Unable to set disk store path for cache");

         }

     }

 }