package de.intevation.flys.artifacts.states;

import java.util.ArrayList;
import java.util.List;
import java.util.Comparator;
import java.util.Collections;

import org.apache.log4j.Logger;

import org.w3c.dom.Element;

import de.intevation.artifacts.Artifact;
import de.intevation.artifacts.CallContext;

import de.intevation.artifactdatabase.ProtocolUtils;
import de.intevation.artifactdatabase.data.StateData;

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

import de.intevation.flys.model.Gauge;
import de.intevation.flys.model.Range;
import de.intevation.flys.model.River;
import de.intevation.flys.model.Wst;

import de.intevation.flys.artifacts.FLYSArtifact;
import de.intevation.flys.artifacts.model.RangeWithValues;
import de.intevation.flys.artifacts.model.WstFactory;


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

    /** The logger used in this state.*/
    private static Logger logger = Logger.getLogger(WQAdapted.class);


    public static final String FIELD_WQ_MODE = "wq_mode";

    public static final String FIELD_WQ_VALUES = "wq_values";

    public static final class GaugeOrder implements Comparator<Gauge> {
        private int order;

        public GaugeOrder(boolean up) {
            order = up ? 1 : -1;
        }

        public int compare(Gauge a, Gauge b) {
            return order * a.getRange().getA().compareTo(b.getRange().getA());
        }
    } // class GaugeOrder

    public static final GaugeOrder GAUGE_UP   = new GaugeOrder(true);
    public static final GaugeOrder GAUGE_DOWN = new GaugeOrder(false);

    public WQAdapted() {
    }

    /**
     * This method creates one element for each gauge of the selected river that
     * is intersected by the given kilometer range. Each element is a tuple of
     * (from;to) where <i>from</i> is the lower bounds of the gauge or the lower
     * kilometer range. <i>to</i> is the upper bounds of the gauge or the upper
     * kilometer range.
     *
     * @param cr The ElementCreator.
     * @param artifact The FLYS artifact.
     * @param name The name of the data item.
     * @param context The CallContext.
     *
     * @return a list of elements that consist of tuples of the intersected
     * gauges of the selected river.
     */
    @Override
    protected Element[] createItems(
        XMLUtils.ElementCreator cr,
        Artifact    artifact,
        String      name,
        CallContext context)
    {
        logger.debug("WQAdapted.createItems");

        if (name != null && name.equals(FIELD_WQ_MODE)) {
            return createModeItems(cr, artifact, name, context);
        }
        else if (name != null && name.equals(FIELD_WQ_VALUES)) {
            return createValueItems(cr, artifact, name, context);
        }
        else {
            logger.warn("Unknown data object: " + name);
            return null;
        }
    }


    protected Element[] createModeItems(
        XMLUtils.ElementCreator cr,
        Artifact    artifact,
        String      name,
        CallContext context)
    {
        logger.debug("WQAdapted.createModeItems");

        Element w = createItem(cr, new String[] { "w", "W" });
        Element q = createItem(cr, new String[] { "q", "Q" });

        return new Element[] { w, q };
    }


    protected Element[] createValueItems(
        XMLUtils.ElementCreator cr,
        Artifact    artifact,
        String      name,
        CallContext context)
    {
        logger.debug("WQAdapted.createValueItems");

        FLYSArtifact flysArtifact = (FLYSArtifact) artifact;

        double[]    dist   = flysArtifact.getDistance();
        List<Gauge> gauges = flysArtifact.getGauges();

        int num = gauges != null ? gauges.size() : 0;

        if (num == 0) {
            logger.warn("Selected distance matches no gauges.");
            return null;
        }

        Element[] elements = new Element[num];

        double rangeFrom = dist[0];
        double rangeTo   = dist[1];

        int idx = 0;

        if (rangeFrom < rangeTo) {
            Collections.sort(gauges, GAUGE_UP);
            for (Gauge gauge: gauges) {
                Range range = gauge.getRange();
                double lower = range.getA().doubleValue();
                double upper = range.getB().doubleValue();

                double from = lower < rangeFrom ? rangeFrom : lower;
                double to   = upper > rangeTo   ? rangeTo   : upper;

                elements[idx++] = createItem(
                    cr, new String[] { from + ";" + to, ""});
            }
        }
        else {
            Collections.sort(gauges, GAUGE_DOWN);
            rangeFrom = dist[1];
            rangeTo   = dist[0];
            for (Gauge gauge: gauges) {
                Range range = gauge.getRange();
                double lower = range.getA().doubleValue();
                double upper = range.getB().doubleValue();

                double from = lower < rangeFrom ? rangeFrom : lower;
                double to   = upper > rangeTo   ? rangeTo   : upper;

                elements[idx++] = createItem(
                    cr, new String[] { to + ";" + from, ""});
            }
        }

        return elements;
    }


    protected Element createItem(XMLUtils.ElementCreator cr, Object obj) {
        Element item  = ProtocolUtils.createArtNode(cr, "item", null, null);
        Element label = ProtocolUtils.createArtNode(cr, "label", null, null);
        Element value = ProtocolUtils.createArtNode(cr, "value", null, null);

        String[] arr = (String[]) obj;

        label.setTextContent(arr[0]);
        value.setTextContent(arr[1]);

        item.appendChild(label);
        item.appendChild(value);

        return item;
    }


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


    @Override
    public boolean validate(Artifact artifact, CallContext context)
    throws IllegalArgumentException
    {
        logger.debug("WQAdapted.validate");

        FLYSArtifact flys = (FLYSArtifact) artifact;
        StateData    data = getData(flys, FIELD_WQ_MODE);

        String mode = data != null ? (String) data.getValue() : null;

        if (mode != null && mode.equals("W")) {
            return validateW(artifact, context);
        }
        else if (mode != null && mode.equals("Q")) {
            return validateQ(artifact, context);
        }
        else {
            throw new IllegalArgumentException("error_feed_no_wq_mode_selected");
        }
    }


    protected boolean validateW(Artifact artifact, CallContext context)
    throws IllegalArgumentException
    {
        logger.debug("WQAdapted.validateW");
        FLYSArtifact flys = (FLYSArtifact) artifact;

        RangeWithValues[] rwvs = extractInput(getData(flys, "wq_values"));

        if (rwvs == null) {
            throw new IllegalArgumentException("error_missing_wq_data");
        }

        List<Gauge>     gauges = ((FLYSArtifact) artifact).getGauges();

        for (Gauge gauge: gauges) {
            Range range  = gauge.getRange();
            double lower = range.getA().doubleValue();
            double upper = range.getB().doubleValue();

            for (RangeWithValues rwv: rwvs) {
                if (lower <= rwv.getLower() && upper >= rwv.getUpper()) {
                    compareWsWithGauge(gauge, rwv.getValues());
                }
            }
        }

        return true;
    }


    protected boolean validateQ(Artifact artifact, CallContext context)
    throws IllegalArgumentException
    {
        logger.debug("WQAdapted.validateQ");
        FLYSArtifact flys = (FLYSArtifact) artifact;

        RangeWithValues[] rwvs = extractInput(getData(flys, "wq_values"));

        if (rwvs == null) {
            throw new IllegalArgumentException("error_missing_wq_data");
        }

        List<Gauge>     gauges = ((FLYSArtifact) artifact).getGauges();
        River            river = ((FLYSArtifact) artifact).getRiver();
        Wst                wst = WstFactory.getWst(river);

        for (Gauge gauge: gauges) {
            Range range  = gauge.getRange();
            double lower = range.getA().doubleValue();
            double upper = range.getB().doubleValue();

            for (RangeWithValues rwv: rwvs) {
                if (lower <= rwv.getLower() && upper >= rwv.getUpper()) {
                    compareQsWithGauge(wst, gauge, rwv.getValues());
                }
            }
        }

        return true;
    }


    protected boolean compareQsWithGauge(Wst wst, Gauge gauge, double[] qs)
    throws IllegalArgumentException
    {
        double[] minmax = gauge != null
            ? wst.determineMinMaxQ(gauge.getRange())
            : null;

        if (minmax == null) {
            logger.warn("Could not determine min/max Q of gauge.");
            return true;
        }

        if (logger.isDebugEnabled()) {
            logger.debug("Validate Qs with:");
            logger.debug("-- Gauge: " + gauge.getName());
            logger.debug("-- Gauge min: " + minmax[0]);
            logger.debug("-- Gauge max: " + minmax[1]);
        }

        for (double q: qs) {
            if (q < minmax[0] || q > minmax[1]) {
                throw new IllegalArgumentException(
                    "error_feed_q_values_invalid");
            }
        }

        return true;
    }


    protected boolean compareWsWithGauge(Gauge gauge, double[] ws)
    throws IllegalArgumentException
    {
        double[] minmax = gauge != null
            ? gauge.determineMinMaxW()
            : null;

        if (minmax == null) {
            logger.warn("Could not determine min/max W of gauge.");
            return true;
        }

        if (logger.isDebugEnabled()) {
            logger.debug("Validate Ws with:");
            logger.debug("-- Gauge: " + gauge.getName());
            logger.debug("-- Gauge min: " + minmax[0]);
            logger.debug("-- Gauge max: " + minmax[1]);
        }

        for (double w: ws) {
            if (w < minmax[0] || w > minmax[1]) {
                throw new IllegalArgumentException(
                    "error_feed_w_values_invalid");
            }
        }

        return true;
    }


    protected RangeWithValues[] extractInput(StateData data) {
        if (data == null) {
            return null;
        }

        String dataString = (String) data.getValue();
        String[]   ranges = dataString.split(":");

        List<RangeWithValues> rwv = new ArrayList<RangeWithValues>();

        for (String range: ranges) {
            String[] parts = range.split(";");

            double lower = Double.parseDouble(parts[0]);
            double upper = Double.parseDouble(parts[1]);

            String[] values = parts[2].split(",");

            int      num = values.length;
            double[] res = new double[num];

            for (int i = 0; i < num; i++) {
                try {
                    res[i] = Double.parseDouble(values[i]);
                }
                catch (NumberFormatException nfe) {
                    logger.warn(nfe, nfe);
                }
            }

            rwv.add(new RangeWithValues(lower, upper, res));
        }

        return (RangeWithValues[]) rwv.toArray(new RangeWithValues[rwv.size()]);
    }
}
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