EDIT

/**

 * Copyright (C) 2007 EDIT

 * European Distributed Institute of Taxonomy

 * http://www.e-taxonomy.eu

 *

 * The contents of this file are subject to the Mozilla Public License Version 1.1

 * See LICENSE.TXT at the top of this package for the full license terms.

 */

package eu.etaxonomy.cdm.persistence.hibernate;

import java.io.Serializable;

import java.util.Set;

import org.apache.log4j.Logger;

import org.hibernate.event.spi.AbstractEvent;

import org.hibernate.event.spi.EventSource;

import org.hibernate.event.spi.PostDeleteEvent;

import org.hibernate.event.spi.PostInsertEvent;

import org.hibernate.event.spi.PostLoadEvent;

import org.hibernate.event.spi.PostUpdateEvent;

import org.hibernate.persister.entity.EntityPersister;

import eu.etaxonomy.cdm.model.common.CdmBase;

/**

 * The CrudEvent unifies all CRUD events into one interface.

 * Crud as in Create, Retrieve, Update, Delete. This event will only hold CdmBase objects.

 *

 *

 * @author n.hoffmann

 * @since 24.03.2009

 */

public class CdmDataChangeEvent extends AbstractEvent{

    private static final long serialVersionUID = 9113025682352080372L;

    private static final Logger logger = Logger.getLogger(CdmDataChangeEvent.class);

    /**

     * The event types currently implemented

     *

     * @author n.hoffmann

     * @since 25.03.2009

     * @version 1.0

     */

    public enum EventType {

        INSERT, LOAD, UPDATE, DELETE

    }

    private final CdmBase entity;

    private final EntityPersister persister;

    private final Set<CdmBase> affectedObjects;

    private final Object[] state;

    // for update only

    private Object[] oldState;

    private final Serializable id;

    protected final EventType eventType;

    /**

     * @param source

     */

    private CdmDataChangeEvent(

            CdmBase entity,

            Serializable id,

            Object[] state,

            Object[] oldState,

            EntityPersister persister,

            EventSource source,

            EventType eventType

            ) {

        super(source);

        this.entity = entity;

        this.id = id;

        this.state = state;

        this.oldState = oldState;

        this.persister = persister;

        this.eventType = eventType;

        this.affectedObjects = null;

    }

    /**

     * @param source

     */

    private CdmDataChangeEvent(

            CdmBase entity,

            Set<CdmBase> affectedObjects,

            EventType eventType

            ) {

        super(null);

        this.entity = entity;

        this.persister = null;

        this.affectedObjects = affectedObjects;

        this.state = null;

        this.oldState = null;

        this.id = null;

        this.eventType = eventType;

    }

    public CdmBase getEntity() {

        return entity;

    }

    public Serializable getId() {

        return id;

    }

    public EntityPersister getPersister() {

        return persister;

    }

    public Object[] getState() {

        return state;

    }

    public Object[] getOldState() {

        if(oldState == null){

            oldState = state;

        }

        return oldState;

    }

    public Set<CdmBase> getAffectedObjects() {

        return affectedObjects;

    }

    public EventType getEventType(){

        return eventType;

    }

    public boolean isInsert(){

        return eventType == EventType.INSERT;

    }

    public boolean isLoad(){

        return eventType == EventType.LOAD;

    }

    public boolean isUpdate(){

        return eventType == EventType.UPDATE;

    }

    public boolean isDelete(){

        return eventType == EventType.DELETE;

    }

    /**

     * @param event

     * @return

     */

    public static CdmDataChangeEvent NewInstance(AbstractEvent event) {

        CdmDataChangeEvent mediationEvent = null;

        try{

            if(event instanceof PostInsertEvent){

                PostInsertEvent postEvent = (PostInsertEvent) event;

                mediationEvent = new CdmDataChangeEvent(

                        (CdmBase)postEvent.getEntity(),

                        postEvent.getId(),

                        postEvent.getState(),

                        null,

                        postEvent.getPersister(),

                        postEvent.getSession(),

                        EventType.INSERT

                        );

            }

            if(event instanceof PostLoadEvent){

                PostLoadEvent updateEvent = (PostLoadEvent) event;

                mediationEvent = new CdmDataChangeEvent(

                        (CdmBase)updateEvent.getEntity(),

                        updateEvent.getId(),

                        null,

                        null,

                        updateEvent.getPersister(),

                        updateEvent.getSession(),

                        EventType.LOAD

                        );

            }

            if(event instanceof PostUpdateEvent){

                PostUpdateEvent updateEvent = (PostUpdateEvent) event;

                mediationEvent = new CdmDataChangeEvent(

                        (CdmBase)updateEvent.getEntity(),

                        updateEvent.getId(),

                        updateEvent.getState(),

                        updateEvent.getOldState(),

                        updateEvent.getPersister(),

                        updateEvent.getSession(),

                        EventType.UPDATE

                        );

            }

            if(event instanceof PostDeleteEvent){

                PostDeleteEvent deleteEvent = (PostDeleteEvent) event;

                mediationEvent = new CdmDataChangeEvent(

                        (CdmBase)deleteEvent.getEntity(),

                        deleteEvent.getId(),

                        deleteEvent.getDeletedState(),

                        null,

                        deleteEvent.getPersister(),

                        deleteEvent.getSession(),

                        EventType.DELETE

                        );

            }

        }catch(ClassCastException e){

            // we are only interested in CdmBase entities, we have the try/catch block in case another entity slips through

            logger.warn("tried to instantiate event for non CdmBase entity");

        }

        return mediationEvent;

    }

    public static CdmDataChangeEvent NewInstance(CdmBase entity, Set<CdmBase> affectedObjects, EventType eventType) {

        return new CdmDataChangeEvent(entity, affectedObjects, eventType);

    }

}