package de.intevation.flys.exports.fixings;

import org.w3c.dom.Element;
import org.w3c.dom.Document;

import org.apache.log4j.Logger;

import java.io.OutputStream;

import javax.xml.xpath.XPathConstants;

import de.intevation.artifacts.ArtifactNamespaceContext;
import de.intevation.artifacts.common.utils.XMLUtils;
import de.intevation.artifacts.CallContext;

import de.intevation.flys.exports.XYChartGenerator;

public abstract class FixChartGenerator
extends XYChartGenerator
{
    private static Logger logger = Logger.getLogger(FixChartGenerator.class);

    public static final String XPATH_CHART_CURRENTKM =
        "/art:action/art:attributes/art:currentKm";


    @Override
    public void init(Document request, OutputStream out, CallContext context) {
        super.init(request, out, context);

        logger.debug("currentKm = " + new Double(getCurrentKmFromRequest()));
        context.putContextValue("currentKm", new Double(getCurrentKmFromRequest()));
    }

    public double getCurrentKmFromRequest() {
        Element km = (Element)XMLUtils.xpath(
            request,
            XPATH_CHART_CURRENTKM,
            XPathConstants.NODE,
            ArtifactNamespaceContext.INSTANCE);

        if (km == null) {
            return -1d;
        }

        String uri = ArtifactNamespaceContext.NAMESPACE_URI;

        String currentKm = km.getAttributeNS(uri, "km");
        try {
            double d = Double.valueOf(currentKm).doubleValue();
            return d;
        }
        catch(NumberFormatException nfe) {
            return -1d;
        }
    }
}