package de.intevation.flys.artifacts.services;

import java.util.Calendar;

import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import de.intevation.artifacts.ArtifactNamespaceContext;
import de.intevation.artifacts.CallMeta;
import de.intevation.artifacts.GlobalContext;
import de.intevation.artifacts.common.utils.XMLUtils;
import de.intevation.flys.artifacts.model.minfo.SedimentLoad;
import de.intevation.flys.artifacts.model.minfo.SedimentLoadFactory;


public class SedimentLoadInfoService
extends FLYSService
{
    /** The logger used in this service. */
    private static Logger logger = Logger.getLogger(SedimentLoadInfoService.class);

    public static final String RIVER_XPATH = "/art:river/text()";
    public static final String TYPE_XPATH = "/art:river/art:type/text()";
    public static final String FROM_XPATH = "/art:river/art:location/art:from/text()";
    public static final String TO_XPATH = "/art:river/art:location/art:to/text()";

    @Override
    protected Document doProcess(
        Document data,
        GlobalContext globalContext,
        CallMeta callMeta) {
        String river = XMLUtils.xpathString(
            data,
            RIVER_XPATH,
            ArtifactNamespaceContext.INSTANCE);
        String type = XMLUtils.xpathString(
            data,
            TYPE_XPATH,
            ArtifactNamespaceContext.INSTANCE);
        String from = XMLUtils.xpathString(
            data,
            FROM_XPATH,
            ArtifactNamespaceContext.INSTANCE);
        String to = XMLUtils.xpathString(
            data,
            TO_XPATH,
            ArtifactNamespaceContext.INSTANCE);
        double f, t;
        try {
            f = Double.parseDouble(from);
            t = Double.parseDouble(to);
        }
        catch (NumberFormatException nfe) {
            logger.warn("Invalid locations. Cannot return sediment loads.");
            return XMLUtils.newDocument();
        }

        SedimentLoad[] loads = SedimentLoadFactory.getLoads(river, type, f, t);
        return buildDocument(loads);
    }

    protected Document buildDocument(SedimentLoad[] loads) {
        Document result = XMLUtils.newDocument();
        Element all = result.createElement("sedimentloads");
        for (SedimentLoad sl : loads) {
            Element load = result.createElement("sedimentload");
            load.setAttribute("description", sl.getDescription());
            if (sl.isEpoch()) {
                Calendar calendarS = Calendar.getInstance();
                calendarS.setTime(sl.getStart());
                Calendar calendarE = Calendar.getInstance();
                calendarE.setTime(sl.getEnd());
                load.setAttribute(
                    "date",
                    calendarS.get(Calendar.YEAR) +
                        " - " +
                        calendarE.get(Calendar.YEAR));
            }
            else {
                Calendar calendar = Calendar.getInstance();
                calendar.setTime(sl.getStart());
                load.setAttribute(
                    "date", 
                    String.valueOf(calendar.get(Calendar.YEAR)));
            }
            all.appendChild(load);
        }
        result.appendChild(all);
        return result;
    }
}