// ODMetaHandler.java
// (C) 2009 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 18.07.2009 on http://yacy.net
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// LICENSE
//
// 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
// (at your option) any later version.
//
// 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

package net.yacy.document.parser.xml;

import java.text.ParseException;
import java.util.Date;
import net.yacy.cora.date.ISO8601Formatter;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class ODMetaHandler extends DefaultHandler {
	private final StringBuilder buffer = new StringBuilder();
	
	private String docCreator = null;
	private String docLanguage = null;
	private String docKeyword = null;
	private String docSubject = null;
	private String docTitle = null;
	private String docDescription = null;
        private String docLastmodified = null;
	
	public ODMetaHandler() {
	}
	
	@Override
	public void characters(final char ch[], final int start, final int length) {
	    buffer.append(ch, start, length);
	}
	
	@Override
	public void startElement(final String uri, final String name, final String tag, final Attributes atts) throws SAXException {
	    buffer.delete(0, buffer.length());
	}

	@Override
	public void endElement(final String uri, final String name, final String tag) {
	    if ("dc:creator".equals(tag)) {
		this.docCreator = buffer.toString();
	    } else if ("dc:language".equals(tag)) {
		this.docLanguage  = buffer.toString();
	    } else if ("meta:keyword".equals(tag)) {
		this.docKeyword  = buffer.toString();
	    } else if ("dc:subject".equals(tag)) {
		this.docSubject  = buffer.toString();
	    } else if ("dc:title".equals(tag)) {
		this.docTitle  = buffer.toString();
	    } else if ("dc:description".equals(tag)) {
		this.docDescription  = buffer.toString();
	    } else if ("dcterms:modified".equals(tag) || "dc:date".equals(tag)) { // Microsoft uses <dcterms:modified>, OpenOffice <dc:date>
                this.docLastmodified = buffer.toString();
            }
	}

	public String getCreator() {
	    return docCreator;
	}

	public String getLanguage() {
	    return docLanguage;
	}
	public String getKeyword() {
	    return docKeyword;
	}
	public String getSubject() {
	    return docSubject;
	}
	public String getTitle() {
	    return docTitle;
	}
	public String getDescription() {
	    return docDescription;
	}

    /**
     * get the last modification date of the document
     *
     * @return date or null
     */
    public Date getLastModified() {
        Date d;
        if (docLastmodified != null && !docLastmodified.isEmpty()) {
            try {
                d = ISO8601Formatter.FORMATTER.parse(this.docLastmodified, 0).getTime();
            } catch (ParseException ex) {
                d = null;
            }
        } else {
            d = null;
        }
        return d;
    }
}