package org.eclipse.jetty.nosql;
   //========================================================================
   //Copyright (c) 2011 Intalio, Inc.
   //------------------------------------------------------------------------
   //All rights reserved. This program and the accompanying materials
   //are made available under the terms of the Eclipse Public License v1.0
   //and Apache License v2.0 which accompanies this distribution.
   //The Eclipse Public License is available at
   //http://www.eclipse.org/legal/epl-v10.html
  //The Apache License v2.0 is available at
  //http://www.opensource.org/licenses/apache2.0.php
  //You may elect to redistribute this code under either of these licenses.
  //========================================================================
  
  import java.util.HashSet;
  import java.util.Set;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import javax.servlet.http.HttpServletRequest;
  
  import org.eclipse.jetty.server.session.AbstractSession;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  
  /* ------------------------------------------------------------ */
  public class NoSqlSession extends AbstractSession
  {
      private final static Logger __log = Log.getLogger("org.eclipse.jetty.server.session");
  
      private final NoSqlSessionManager _manager;
      private Set<String> _dirty;
      private final AtomicInteger _active = new AtomicInteger();
      private Object _version;
      private long _lastSync;
  
      /* ------------------------------------------------------------ */
      public NoSqlSession(NoSqlSessionManager manager, HttpServletRequest request)
      {
          super(manager, request);
          _manager=manager;
          save(true);
          _active.incrementAndGet();
      }
      
      /* ------------------------------------------------------------ */
      public NoSqlSession(NoSqlSessionManager manager, long created, long accessed, String clusterId, Object version)
      {
          super(manager, created,accessed,clusterId);
          _manager=manager;
          _version=version;
      }
      
      /* ------------------------------------------------------------ */
      @Override
      public Object doPutOrRemove(String name, Object value)
      {
          synchronized (this)
          {
              if (_dirty==null)
                  _dirty=new HashSet<String>();
              _dirty.add(name);
              Object old = super.doPutOrRemove(name,value);
              if (_manager.getSavePeriod()==-2)
                  save(true);
              return old;
          }
      }
  
      /* ------------------------------------------------------------ */
      @Override
      protected void checkValid() throws IllegalStateException
      {
          super.checkValid();
      }
  
      /* ------------------------------------------------------------ */
      @Override
      protected boolean access(long time)
      {
          __log.debug("NoSqlSession:access:active "+_active);
          if (_active.incrementAndGet()==1)
          {
              long period=_manager.getStalePeriod()*1000L;
              if (period==0)
                  refresh();
              else if (period>0)
              {
                  long stale=time-_lastSync;
                  __log.debug("NoSqlSession:access:stale "+stale);
                  if (stale>period)
                      refresh();
              }
          }
  
          return super.access(time);
      }
  
      /* ------------------------------------------------------------ */
     @Override
     protected void complete()
     {
         super.complete();
         if(_active.decrementAndGet()==0)
         {
             switch(_manager.getSavePeriod())
             {
                 case 0: 
                     save(isValid());
                     break;
                 case 1:
                     if (isDirty())
                         save(isValid());
                     break;
 
             }
         }
     }
 
     /* ------------------------------------------------------------ */
     @Override
     protected void doInvalidate() throws IllegalStateException
     {
         super.doInvalidate();
         save(false);
     }
     
     /* ------------------------------------------------------------ */
     protected void save(boolean activateAfterSave)
     {
         synchronized (this)
         {
             _version=_manager.save(this,_version,activateAfterSave);
             _lastSync=getAccessed();
         }
     }
 
 
     /* ------------------------------------------------------------ */
     protected void refresh()
     {
         synchronized (this)
         {
             _version=_manager.refresh(this,_version);
         }
     }
 
     /* ------------------------------------------------------------ */
     public boolean isDirty()
     {
         synchronized (this)
         {
             return _dirty!=null && !_dirty.isEmpty();
         }
     }
     
     /* ------------------------------------------------------------ */
     public Set<String> takeDirty()
     {
         synchronized (this)
         {
             Set<String> dirty=_dirty;
             if (dirty==null)
                 dirty= new HashSet<String>();
             else
                 _dirty=null;
             return dirty;
         }
     }
 
     /* ------------------------------------------------------------ */
     public Object getVersion()
     {
     	return _version;
     }
     
 }