/*
    * This file is part of Domingo
    * an Open Source Java-API to Lotus Notes/Domino
    * hosted at http://domingo.sourceforge.net
    *
    * Copyright (c) 2003-2007 Beck et al. projects GmbH Munich, Germany (http://www.bea.de)
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  package de.bea.domingo.proxy;
  
  import lotus.domino.Agent;
  import lotus.domino.AgentContext;
  import lotus.domino.Base;
  import lotus.domino.Database;
  import lotus.domino.DateRange;
  import lotus.domino.DateTime;
  import lotus.domino.DbDirectory;
  import lotus.domino.Document;
  import lotus.domino.DocumentCollection;
  import lotus.domino.EmbeddedObject;
  import lotus.domino.Form;
  import lotus.domino.Item;
  import lotus.domino.Log;
  import lotus.domino.NotesException;
  import lotus.domino.RichTextItem;
  import lotus.domino.Session;
  import lotus.domino.View;
  import lotus.domino.ViewEntry;
  import lotus.domino.ViewEntryCollection;
  import lotus.domino.ViewNavigator;
  import de.bea.domingo.DNotesMonitor;
  import de.bea.domingo.exception.DominoException;
  import de.bea.domingo.monitor.AbstractMonitorEnabled;
  import de.bea.domingo.queue.Queue;
  
  /***
   * Implementation of interface <code>NotesRecycler</code> that explicitly
   * recycles almost all Notes objects.
   *
   * <p>This strategy should be used with Lotus Notes R5 while missing explicit
   * recycle results in memory leaks.</p>
   *
   * @author <a href=mailto:kriede@users.sourceforge.net>Kurt Riede</a>
   */
  public final class RecycleStrategy extends AbstractMonitorEnabled implements NotesRecycler {
  
      /*** Reference to a recycle queue. */
      private Queue recycleQueue = new NotesRecycleQueue();
  
      /*** Indicates whether the DateTime recycle problem is already reported.*/
      private boolean dateTimeHitfixProblemReported = false;
  
      /***
       * Constructor.
       *
       * @param monitor the monitor
       */
      public RecycleStrategy(final DNotesMonitor monitor) {
          super(monitor);
      }
  
      /***
       * {@inheritDoc}
       * @see de.bea.domingo.proxy.NotesRecycler#recycleLater(java.lang.Object)
       */
      public synchronized void recycleLater(final Object object) {
          final Base notesBase = getNotesObject(object);
          if (notesBase != null) {
              recycleQueue.enqueue(notesBase);
          }
      }
  
      /***
       * @see de.bea.domingo.proxy.NotesRecycler#recycleQueue()
       */
      public synchronized void recycleQueue() {
          if (!recycleQueue.isEmpty()) {
              while (!recycleQueue.isEmpty()) {
                  final Object obj = recycleQueue.dequeue();
                  if (obj != null) {
                      recycle(obj);
                  }
              }
          }
      }
 
     /***
      * {@inheritDoc}
      * @see de.bea.domingo.proxy.NotesRecycler#recycle(java.lang.Object)
      */
     public synchronized void recycle(final Object object) {
         final Base notesBase = getNotesObject(object);
         try {
             if (notesBase == null) {
                 return; // ignore null values
             } else if (notesBase instanceof Session) {
                 notesBase.recycle();
             } else if (notesBase instanceof DbDirectory) {
                 notesBase.recycle();
             } else if (notesBase instanceof Database) {
                 notesBase.recycle();
             } else if (notesBase instanceof Log) {
                 return; // TODO Check how a Log must be recycled properly. notesBase.recycle();
             } else if (notesBase instanceof View) {
                 notesBase.recycle();
             } else if (notesBase instanceof ViewNavigator) {
                 notesBase.recycle();
             } else if (notesBase instanceof ViewEntryCollection) {
                 return; // don't recycle entry collections
             } else if (notesBase instanceof ViewEntry) {
                 notesBase.recycle();
             } else if (notesBase instanceof DocumentCollection) {
                 notesBase.recycle();
             } else if (notesBase instanceof Document) {
                 notesBase.recycle();
             } else if (notesBase instanceof Item) {
                 return; // don't recycle items
             } else if (notesBase instanceof RichTextItem) {
                 return; // don't recycle items
             } else if (notesBase instanceof EmbeddedObject) {
                 return; // don't recycle embedded objects
             } else if (notesBase instanceof Form) {
                 notesBase.recycle();
             } else if (notesBase instanceof Agent) {
                 notesBase.recycle();
             } else if (notesBase instanceof AgentContext) {
                 notesBase.recycle();
             } else if (notesBase instanceof DateTime) {
                 recycleDateTime((DateTime) notesBase);
             } else if (notesBase instanceof DateRange) {
                 notesBase.recycle();
             } else {
                 getMonitor().debug("No explicit recycle strategy found for class " + notesBase.getClass().getName());
                 notesBase.recycle();
             }
         } catch (NotesException e) {
             getMonitor().warn("Cannot recycle " + notesBase.getClass().getName(), new DominoException(e));
         }
     }
 
     /***
      * Recycles a Notes date/time object.
      *
      * @param dateTime the date/time object
      */
     private void recycleDateTime(final DateTime dateTime) {
         try {
             if (dateTime.getParent() == null) {
                 //
                 // DateTime objects that only have a Date component seem
                 // not to have a parent session in Release 5.0.8 and 5.0.11
                 // without the HotFix of the file notes.jar from Lotus.
                 // It is impossible to recycle such objects, so we log an error here.
                 //
                 // See also Lotus Software Problem report (SPR):
                 // http://www.ibm.com/support/docview.wss?uid=sim4ae8f437f0c71ea0b85256c9f00791c48
                 // -> SPR# MKIN5CYTH4 - Fixed a null pointer exception when calling
                 //                      the recycle method of DateTime class
                 //
                 if (!dateTimeHitfixProblemReported) {
                     dateTimeHitfixProblemReported = true;
                     getMonitor().fatalError("recycle a DateTime object without parent session.");
                 }
             } else {
                 dateTime.recycle();
             }
         } catch (NotesException e) {
             getMonitor().warn("recycle DateTime with parent session not available.", new DominoException(e));
         }
     }
 
     /***
      * Given any object (might be a Domingo object or a Notes object) returns
      * the base notes object if available.
      *
      * @return notes object
      */
     private Base getNotesObject(final Object object) {
         final Base notesBase;
         if (object instanceof BaseProxy) {
             notesBase = ((BaseProxy) object).getNotesObject();
         } else if (object instanceof Base) {
             notesBase = (Base) object;
         } else {
             notesBase = null;
         }
         return notesBase;
     }
 }