/*
 * $Header: /cvsroot/mvnforum/mvnforum/src/com/mvnforum/search/post/RebuildPostIndexTask.java,v 1.5 2005/01/18 11:52:23 minhnn Exp $
 * $Author: minhnn $
 * $Revision: 1.5 $
 * $Date: 2005/01/18 11:52:23 $
 *
 * ====================================================================
 *
 * Copyright (C) 2002-2005 by MyVietnam.net
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * All copyright notices regarding mvnForum MUST remain intact
 * in the scripts and in the outputted HTML.
 * The "powered by" text/logo with a link back to
 * http://www.mvnForum.com and http://www.MyVietnam.net in the
 * footer of the pages MUST remain visible when the pages
 * are viewed on the internet or intranet.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Support can be obtained from support forums at:
 * http://www.mvnForum.com/mvnforum/index
 *
 * Correspondence and Marketing Questions can be sent to:
 * info@MyVietnam.net
 *
 * @author: Minh Nguyen  minhnn@MyVietnam.net
 * @author: Dejan Krsmanovic dejan_krsmanovic@yahoo.com
 */
package com.mvnforum.search.post;

import java.io.IOException;
import java.util.*;

import com.mvnforum.db.DAOFactory;
import com.mvnforum.db.PostBean;
import net.myvietnam.mvncore.exception.DatabaseException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.lucene.index.IndexWriter;


/**
 * Rebuilding indices task. This task do indexing of all documents
 */
public class RebuildPostIndexTask extends TimerTask
{
    private static Log log = LogFactory.getLog(RebuildPostIndexTask.class);

    public static final int POST_PER_GROUPS = 500;

    public static final int MERGE_FACTOR  = 20;

    private int maxPostID = 0;

    private static boolean isRebuilding = false;

    public static boolean isRebuilding() {
        return isRebuilding;
    }

    /*
     * Contructor with default access, prevent new an instance from outside package
     */
    RebuildPostIndexTask(int maxPostID) {
        this.maxPostID = maxPostID;
    }

    /**
     * Create new index. If anything exist already - delete it
     */
    public void run() {
        isRebuilding = true;
        long start = System.currentTimeMillis();

        IndexWriter writer = null;
        try {
            writer = PostIndexer.getIndexWriter(true);
            writer.mergeFactor = MERGE_FACTOR;
            // note that the postTotal is get at the begining of the method
            // so that it will index only these posts. Later while indexing,
            // if new posts are added, then other task will take care it
            int postTotal = DAOFactory.getPostDAO().getNumberOfPosts();
            int index = 0;
            int offset = 0;
            while (index < postTotal) {
                // Please note that is method sorted by PostCreationDate ASC
                Collection posts = DAOFactory.getPostDAO().getLimitPosts(offset, POST_PER_GROUPS);
                for (Iterator iter = posts.iterator(); iter.hasNext(); ) {
                    PostBean post = (PostBean) iter.next();
                    PostIndexer.doIndexPost(post, writer);
                    index++;
                }
                offset = index;
            } //end while
            writer.optimize();
            log.info("Rebuilt index finished successfully! " + index + " post(s) indexed.");
        } catch (DatabaseException ex) {
            log.error("RebuildIndexTask.run : cannot get posts from database for indexing", ex);
        } catch (Exception e) {
            log.error("Error while rebuilding index", e);
        } finally {
            try {
                if (writer != null) {
                    writer.close();
                }
            } catch (IOException ignore) {
            }
        }
        log.info("RebuildIndexTask took " + (System.currentTimeMillis() - start) + " ms");
        isRebuilding = false;
    }
}