/**
    * This file Copyright (c) 2010-2010 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.mbean;
  
  import info.magnolia.cms.util.MBeanUtil;
  import info.magnolia.commands.CommandsManager;
  import info.magnolia.context.Context;
  import info.magnolia.context.MgnlContext;
  import info.magnolia.context.SimpleContext;
  import info.magnolia.module.ModuleRegistry;
  import info.magnolia.module.cache.Cache;
  import info.magnolia.module.cache.CacheFactory;
  import info.magnolia.module.cache.CacheModule;
  import info.magnolia.module.cache.DefaultCacheKey;
  import info.magnolia.module.cache.cachepolicy.Default;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.commons.chain.Command;
  
  /**
   * <code>MBean</code> implementation for the cache status.
   * @author had
   * @version $Id:$
   */
  public class CacheMonitor implements CacheMonitorMBean {
  
      private static CacheMonitor instance = new CacheMonitor();
      private int start;
      private int stop;
      private Map<String, Integer> calls = new HashMap<String, Integer>();
      private Map<String, Integer> caches = new HashMap<String, Integer>();
      private Map<String, Integer> domains = new HashMap<String, Integer>();
      private CommandsManager commandsManager;
  
      public CacheMonitor() {
          MBeanUtil.registerMBean("CacheMonitor", this);
          commandsManager = CommandsManager.getInstance();
      }
  
      private CacheFactory getCacheFactory() {
          CacheFactory factory = ModuleRegistry.Factory.getInstance().getModuleInstance(CacheModule.class).getCacheFactory();
          return factory;
      }
  
      private Command getCommand(String commandName) {
          Command flush = commandsManager.getCommand("cache", commandName);
          if (flush == null) {
              // TODO: why does it happen that commands are not ready?
              commandsManager.reload();
              flush = commandsManager.getCommand("cache", commandName);
          }
          if (flush == null) {
              throw new RuntimeException("Failed to invoke cache " + commandName + " command");
          }
          return flush;
      }
  
      public static CacheMonitor getInstance() {
          return instance;
      }
  
      public void countStart() {
          start++;
      }
  
      public void stop() {
         stop++;
     }
 
     /**
      * @param name
      */
     public void logBehavior(String name) {
         Integer count = calls.get(name);
         calls.put(name, count == null ? 1 : ++count);
     }
 
     public void countFlush(String name) {
         caches.put(name, caches.get(name) + 1);
     }
 
     public void addCache(String name) {
         caches.put(name, 0);
     }
 
     public void logAccess(Object cacheKey) {
         if (cacheKey == null || !(cacheKey instanceof DefaultCacheKey)) {
             return;
         }
         DefaultCacheKey key = (DefaultCacheKey) cacheKey;
         Integer count = this.domains.get(key.getDomain());
         this.domains.put(key.getDomain(), count == null ? 1 : ++count);
     }
 
     // mbean exposed operations
     public void flushAll() throws Exception {
         Command flush = getCommand("flushAll");
         flush.execute(MgnlContext.getSystemContext());
     }
 
     public void flushByUUID(String repository, String uuid) throws Exception {
         Command flush = getCommand("flushByUUID");
         Context ctx = new SimpleContext(MgnlContext.getSystemContext());
         ctx.put("repository", repository);
         ctx.put("uuid", uuid);
         flush.execute(ctx);
     }
 
     // mbean exposed attributes
     public Map<String, Integer> getAll() {
         return calls;
     }
 
     public int getHits() {
         return calls.get("useCache");
     }
 
     public int getBypasses() {
         return calls.get("bypass");
     }
 
     public int getPuts() {
         return calls.get("store");
     }
 
     public int getStopCalls() {
         return stop;
     }
 
     public int getStartCalls() {
         return start;
     }
 
     public Map<String, Integer> getFlushes() {
         return caches;
     }
 
     public Map<String, Integer> getDomainAccesses() {
         return domains;
     }
 
     public int getCachedKeysCount() {
         int count = 0;
         // there's most likely gonna be ever just one map in the default cache, but let's not assume that and search all configured caches
         CacheFactory factory = getCacheFactory();
         for (String name : caches.keySet()) {
             // skip the uuid-key cache itself
             if (Default.UUID_KEY_MAP_KEY.equals(name)) {
                 continue;
             }
             Cache cache = factory.getCache(name);
             count += cache.getSize();
         }
         return count;
     }
 
     public int getCachedUUIDsCount() {
         CacheFactory factory = getCacheFactory();
         Cache cache = factory.getCache(Default.UUID_KEY_MAP_KEY);
         return cache.getSize();
     }
 }