package org.dive4elements.river.exports.injector;

import org.apache.log4j.Logger;
import org.dive4elements.artifacts.Artifact;
import org.dive4elements.artifacts.CallContext;
import org.dive4elements.artifacts.ContextInjector;
import org.dive4elements.river.artifacts.D4EArtifact;
import org.dive4elements.river.artifacts.access.RangeAccess;
import org.dive4elements.river.model.Gauge;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import static org.dive4elements.river.exports.injector.InjectorConstants.CURRENT_KM;
import static org.dive4elements.river.exports.injector.InjectorConstants.GAUGE_EPSILON;;


public class DischargeInjector
implements ContextInjector
{

    private static Logger log = Logger.getLogger(DischargeInjector.class);

    @Override
    public void setup(Element cfg) {
    }

    @Override
    public void injectContext(CallContext ctx, Artifact artifact, Document doc) {
        RangeAccess access = new RangeAccess((D4EArtifact)artifact);
        if (!access.hasFrom()) {
            return;
        }
        double km = access.getFrom();
        Gauge gauge = access.getRiver().determineGaugeByStation(
            km - GAUGE_EPSILON, km + GAUGE_EPSILON);
        if (gauge == null) {
            log.error("No Gauge could be found at station " + km + "!");
            return;
        }
        ctx.putContextValue(CURRENT_KM, km);
    }

}