EDIT

// $Id$

/**

 * 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.util.List;

import org.hibernate.HibernateException;

import org.hibernate.Session;

import org.hibernate.event.spi.SaveOrUpdateEvent;

import org.hibernate.event.spi.SaveOrUpdateEventListener;

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

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

@SuppressWarnings("serial")

public class SaveOrUpdateEntityListener implements SaveOrUpdateEventListener{

    @Override

    public void onSaveOrUpdate(SaveOrUpdateEvent event) throws HibernateException {

        //System.err.println("SaveOrUpdateListener" + event.getEntity().getClass());

        Object entity = event.getObject();

        saveOrUpdate(entity, event.getSession());

    }

    private void saveOrUpdate(Object entity, Session session) {

        //moved to CdmPreDataChangeListener

        if(entity != null && CdmBase.class.isAssignableFrom(entity.getClass())){

            if (entity instanceof ITreeNode) {

                ITreeNode<?> node = (ITreeNode<?>)entity;

                reindex(node);

            }

        }

    }

    static String sep = ITreeNode.separator;

    static String pref = ITreeNode.treePrefix;

    /**

     * @param event

     * @param node

     */

    private <T extends ITreeNode> void reindex(T node) {

        String oldChildIndex = node.treeIndex();

        ITreeNode<?> parent = node.getParent();

        String parentIndex = (parent == null) ? (sep + pref + node.treeId() + sep)  : parent.treeIndex();  //TODO

        if (node.getId() > 0){   //TODO

            String newChildIndex = parentIndex + node.getId() + sep;

            if (oldChildIndex == null || ! oldChildIndex.equals(newChildIndex)){

                node.setTreeIndex(newChildIndex);

                //TODO this is a greedy implementation, better use update by replace string

                //either using and improving the below code or by using native SQL

                //The current approach may run out of memory for large descendant sets.

                List<T> childNodes = node.getChildNodes();

                for (T child : childNodes){

                    if (child != null && ! child.equals(node)){  //node should not be it's own child, however just in case

                        reindex(child);

                    }

                }

                //			String className = event.getEntityName();

                //					String updateQuery = " UPDATE %s tn " +

                //							" SET tn.treeIndex = Replace(tn.treeIndex, '%s', '%s') " +

                //							" WHERE tn.id <> "+ node.getId()+" ";

                //					updateQuery = String.format(updateQuery, className, oldChildIndex, parentIndex);  //dummy

                //					System.out.println(updateQuery);

                //					EventSource session = event.getSession();

                //					Query query = session.createQuery(updateQuery);

                //					query.executeUpdate();

            }

        }

    }

}