package de.intevation.flys.artifacts.states;

import java.util.Calendar;
import java.util.List;

import org.apache.log4j.Logger;
import org.hibernate.SQLQuery;
import org.hibernate.Session;
import org.hibernate.type.StandardBasicTypes;

import de.intevation.flys.artifacts.FLYSArtifact;
import de.intevation.flys.backend.SessionHolder;
import de.intevation.flys.model.Gauge;
import de.intevation.flys.utils.FLYSUtils;


/**
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 */
public class GaugeTimerangeState extends IntRangeState {

    private static final Logger logger =
            Logger.getLogger(GaugeTimerangeState.class);


    protected int[] getLowerUpper(FLYSArtifact flys) {
        Gauge gauge = FLYSUtils.getReferenceGauge(flys);

        if (gauge == null) {
            logger.warn("No reference gauge specified!");
            return new int[] { 0, 0 };
        }

        Session session = SessionHolder.HOLDER.get();

        SQLQuery query = session.createSQLQuery(
                "SELECT min(start_time) as min, max(stop_time) as max " +
                        "FROM time_intervals WHERE id in " +
                        "(SELECT time_interval_id FROM discharge_tables " +
                "WHERE gauge_id =:gid)");

        query.addScalar("min", StandardBasicTypes.CALENDAR);
        query.addScalar("max", StandardBasicTypes.CALENDAR);

        query.setInteger("gid", gauge.getId());

        List<?> results = query.list();

        if (results != null) {
            Object[] res = (Object[]) results.get(0);

            Calendar lo = (Calendar) res[0];
            Calendar up = (Calendar) res[1];

            if (lo != null && up != null) {
                return new int[] { lo.get(Calendar.YEAR), up.get(Calendar.YEAR) };
            }
        }

        logger.warn("Could not determine time range for gauge: " + gauge);

        return null;
    }


    @Override
    protected Object getLower(FLYSArtifact flys) {
        int[] lowerUpper = getLowerUpper(flys);

        return lowerUpper != null ? lowerUpper[0] : 0;
    }


    @Override
    protected Object getUpper(FLYSArtifact flys) {
        int[] lowerUpper = getLowerUpper(flys);

        return lowerUpper != null ? lowerUpper[1] : 0;
    }


    @Override
    protected String getUIProvider() {
        return "gaugetimerange";
    }
}
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