// License: GPL. Copyright 2007 by Immanuel Scholz and others
package org.openstreetmap.josm.io;

import static org.openstreetmap.josm.tools.I18n.tr;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.HashMap;
import java.util.Map;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Read only the ids and classes of an stream.
 *
 * @author Imi
 */
public class OsmIdReader extends DefaultHandler {

    private boolean cancel;
    Map<Long, String> entries = new HashMap<Long, String>();
    private Reader in;

    @Override public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException {
        if (qName.equals("node") || qName.equals("way") || qName.equals("relation")) {
            try {
                entries.put(Long.valueOf(atts.getValue("id")), qName);
            } catch (Exception e) {
                e.printStackTrace();
                throw new SAXException(tr("Error during parse."));
            }
        }
    }

    public Map<Long, String> parseIds(InputStream in) throws IOException, SAXException {
        this.in = new InputStreamReader(in, "UTF-8");
        try {
            SAXParserFactory.newInstance().newSAXParser().parse(new InputSource(this.in), this);
        } catch (ParserConfigurationException e) {
            if (!cancel) {
                e.printStackTrace(); // broken SAXException chaining
                throw new SAXException(e);
            }
        } catch (SAXException e) {
            if (!cancel)
                throw e;
        }
        return entries;
    }

    public void cancel() {
        cancel = true;
        if (in != null)
            try {in.close();} catch (IOException e) {}
    }
}