/*  PAT: Persistent Applications Toolkit (patsystem.sf.net)
 *  Copyright (C) 2004, 2005  Tomasz Nazar, nthx at irc dot pl
 *
 *  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 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
 *
 *  Full version of the license is /docs/LICENSE.txt
 */
package org.nthx.pat;

import org.apache.log4j.Logger;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.Collection;

/** Mixin for {@link IdentityMap} interface.
 *
 *  @version $Id: IdentityMapMixin.java 3725 2005-06-09 23:57:03Z nthx $
 *  @author nthx@users.sourceforge.net
 */
public class IdentityMapMixin
       implements IdentityMap, Serializable
{
    //--- Fields internal -------
    private transient static Logger log = Logger.getLogger("pat");

    //--- Fields ----------------
    private Map map;
    private long uniqueOID;


    //--- Constructors ----------
    public IdentityMapMixin()
    {
        uniqueOID = 1L;
        map = new HashMap();
    }

    //--- Getters and Setters ---
    Map getMap(){ return map; }
    public Map getMapForTestsOnly(){ return map; }
    public void setMap(Map map) { this.map = map; }
    public void setUniqueOID(long uniqueOID) { this.uniqueOID = uniqueOID; }
    public long getUniqueOID() { return uniqueOID; }

    public int getSize() { return getMap().size(); }

    //--- Implementation --------
    public Identifiable putObject(Identifiable identifiable)
    {
        if (null == identifiable) return null;
        if (null != identifiable.getOID())
            throw new IllegalStateException("Trying to put BO which has OID already set: " 
                    + "\nOID: " + identifiable.getOID() + " object: " + identifiable
                    + "\nThis is a BUG. Please send this output to: nthx at users.sf.net"
                        
            );

        //if object already exists
        Identifiable existing = getObject(identifiable.getOID());
        if (null != existing)
        {
            throw new IllegalStateException(
                "Not inserting: " + identifiable
                + "\n.. Because it exists there as: " + existing);
        }
        

        Long oid = generateUniqueOID();
        identifiable.setOID(oid);

//        log.debug("Put: " + oid + " " + identifiable.getClass());
//        log.debug("Inserted: " + identifiable);

        return (Identifiable) getMap().put(identifiable.getOID(), identifiable);
    }

    public Identifiable getObject(Long oid)
    {
        return (Identifiable) getMap().get(oid);
    }

    /** Designed for removing objects which were created as temporary objects or
     *  for objects that were in failed transaction.
     *  xxx: create client's API for that or use WeakHashMap?
     */
    public Identifiable removeObject(Identifiable bo)
    {
        return (Identifiable) getMap().remove(bo.getOID());
    }

    public Long generateUniqueOID()
    {
        return new Long(uniqueOID++);
    }
    
    public Collection keySet()
    {
        return getMap().keySet();
    }
    
    public Collection values()
    {
        return getMap().values();
    }

    final static long serialVersionUID = 1L;
}