/* Copyright (C) 2017 by Bundesanstalt für Gewässerkunde
 * Software engineering by
 *  Björnsen Beratende Ingenieure GmbH
 *  Dr. Schumacher Ingenieurbüro für Wasser und Umwelt
 *
 * This file is Free Software under the GNU AGPL (>=v3)
 * and comes with ABSOLUTELY NO WARRANTY! Check out the
 * documentation coming with Dive4Elements River for details.
 */

package org.dive4elements.river.artifacts.common;

import java.util.Map;
import java.util.Set;

import org.apache.log4j.Logger;
import org.dive4elements.artifactdatabase.state.ArtifactAndFacet;
import org.dive4elements.artifactdatabase.state.Facet;
import org.dive4elements.artifacts.Artifact;
import org.dive4elements.artifacts.CallContext;
import org.dive4elements.river.artifacts.D4EArtifact;
import org.dive4elements.river.artifacts.access.RiverAccess;
import org.dive4elements.river.artifacts.context.RiverContext;
import org.dive4elements.river.artifacts.math.MovingAverage;
import org.dive4elements.river.artifacts.model.WQKms;
import org.dive4elements.river.artifacts.model.ZoomScale;
import org.dive4elements.river.artifacts.resources.Resources;
import org.dive4elements.river.artifacts.sinfo.common.AbstractTkhCalculationResult;
import org.dive4elements.river.artifacts.states.DefaultState.ComputeType;
import org.dive4elements.river.exports.DiagramGenerator;
import org.dive4elements.river.exports.StyledSeriesBuilder;
import org.dive4elements.river.exports.process.DefaultProcessor;
import org.dive4elements.river.jfree.StyledAreaSeriesCollection;
import org.dive4elements.river.jfree.StyledXYSeries;
import org.dive4elements.river.themes.ThemeDocument;

/**
 * Abstraction for some processor implementation within S-INFO. Probably this abstraction could also be used for other
 * cases as well.
 *
 * @author Gernot Belger
 *
 */

public abstract class AbstractProcessor extends DefaultProcessor {

    protected static final double GAP_DISTANCE = 0.101;

    private final static Logger log = Logger.getLogger(AbstractProcessor.class);

    private String yAxisLabel;

    private final Set<String> handled_facet_types;

    private final String i18n_axis_label;

    public AbstractProcessor(final String i18n_axis_label, final Set<String> handled_facet_types) {
        this.i18n_axis_label = i18n_axis_label;
        this.handled_facet_types = handled_facet_types;
    }

    @Override
    public final void doOut(final DiagramGenerator generator, final ArtifactAndFacet bundle, final ThemeDocument theme, final boolean visible) {
        try {
            this.yAxisLabel = generateSeries(generator, bundle, theme, visible);
        }
        catch (final Exception e) {
            log.error(e.getMessage(), e);
        }
    }

    protected static final AbstractCalculationResult getResult(final DiagramGenerator generator, final ArtifactAndFacet bundle) {
        final CallContext context = generator.getContext();
        final AbstractCalculationResult data = (AbstractCalculationResult) bundle.getData(context);
        if (data == null) {
            // Check has been here before so we keep it for security reasons
            // this should never happen though.
            final String facetName = bundle.getFacetName();
            throw new IllegalStateException("Data is null for facet: " + facetName);
        }

        return data;
    }

    /**
     * @return The axis label
     */
    protected abstract String generateSeries(final DiagramGenerator generator, final ArtifactAndFacet bundle, final ThemeDocument theme, final boolean visible);

    protected final String buildSeriesForType(final DiagramGenerator generator, final ArtifactAndFacet bundle, final ThemeDocument theme, final boolean visible,
            final IResultType resultType, final Double gapDistance) {

        final AbstractCalculationResult data = getResult(generator, bundle);

        final double[][] points = data.getStationPoints(resultType);

        return buildSeriesForPoints(points, generator, bundle, theme, visible, gapDistance);
    }

    protected final String buildSeriesForPoints(final double[][] points, final DiagramGenerator generator, final ArtifactAndFacet bundle,
            final ThemeDocument theme, final boolean visible, final Double gapDistance) {
        final CallContext context = generator.getContext();
        final Map<String, String> metaData = bundle.getFacet().getMetaData();

        final Artifact artifact = bundle.getArtifact();

        final String facetDescription = bundle.getFacetDescription();
        final String facetName = bundle.getFacetName();

        final StyledXYSeries series = new StyledXYSeries(facetName, facetDescription, theme);
        series.putMetaData(metaData, artifact, context);

        final double[][] filteredPoints = filterPoints(points, context, artifact, facetName);

        if (gapDistance == null)
            StyledSeriesBuilder.addPoints(series, filteredPoints, true);
        else
            StyledSeriesBuilder.addPoints(series, filteredPoints, true, gapDistance);

        generator.addAxisSeries(series, getAxisName(), visible);

        return metaData.get("Y");
    }

    protected final String buildStepLineSeriesForType(final double[][] points, final DiagramGenerator generator, final ArtifactAndFacet bundle,
            final ThemeDocument theme, final boolean visible) {

        final CallContext context = generator.getContext();
        final Map<String, String> metaData = bundle.getFacet().getMetaData();

        final Artifact artifact = bundle.getArtifact();

        final String facetName = bundle.getFacetName();
        final String facetDescription = bundle.getFacetDescription();

        final StyledXYSeries series = new StyledXYSeries(facetName, facetDescription, theme);
        series.putMetaData(metaData, artifact, context);

        // Create WQKms to use the step points method
        // REMARK: must have any values in w array; not sure whether the name is needed
        final WQKms wqkms = new WQKms(points[0], points[1], points[1], facetName);

        StyledSeriesBuilder.addStepPointsKmQ(series, wqkms);

        generator.addAxisSeries(series, getAxisName(), visible);

        return metaData.get("Y");
    }

    protected final String buildSeriesForTkh(final DiagramGenerator generator, final ArtifactAndFacet bundle, final ThemeDocument theme,
            final boolean visible) {

        final AbstractTkhCalculationResult data = (AbstractTkhCalculationResult) getResult(generator, bundle);

        final String facetName = bundle.getFacetName();
        final String facetDescription = bundle.getFacetDescription();

        final StyledXYSeries seriesUp = new StyledXYSeries(facetName, facetDescription, theme);
        final double[][] pointsUp = data.getTkhUpPoints();
        StyledSeriesBuilder.addPoints(seriesUp, pointsUp, true);

        // REMARK: we add " " because the description is misused as id, which must be unique.
        final StyledXYSeries seriesDown = new StyledXYSeries(facetName, facetDescription + " ", theme);
        final double[][] pointsDown = data.getTkhDownPoints();
        StyledSeriesBuilder.addPoints(seriesDown, pointsDown, true);

        final StyledAreaSeriesCollection area = new StyledAreaSeriesCollection(facetName, theme);
        area.setMode(StyledAreaSeriesCollection.FILL_MODE.BETWEEN);
        area.addSeries(seriesUp);
        area.addSeries(seriesDown);

        generator.addAxisDataset(area, getAxisName(), visible);

        return null;
    }

    private Double findRadius(final CallContext context, final Artifact artifact) {
        final Double start = (Double) context.getContextValue("startkm");
        final Double end = (Double) context.getContextValue("endkm");

        if (start == null || end == null)
            return null;

        final RiverContext fc = (RiverContext) context.globalContext();
        final ZoomScale scales = (ZoomScale) fc.get("zoomscale");
        final RiverAccess access = new RiverAccess((D4EArtifact) artifact);
        final String river = access.getRiverName();

        return scales.getRadius(river, start, end);
    }

    private double[][] filterPoints(final double[][] points, final CallContext context, final Artifact artifact, final String facetName) {

        if (facetName.endsWith(".filtered")) {
            final Double radius = findRadius(context, artifact);
            return movingAverage(radius, points);
        }

        return points;
    }

    private double[][] movingAverage(final Double radius, final double[][] points) {

        if (radius == null)
            return points;

        return MovingAverage.weighted(points, radius);
    }

    @Override
    public final boolean canHandle(final String facettype) {
        return this.handled_facet_types.contains(facettype);
    }

    @Override
    public final String getAxisLabel(final DiagramGenerator generator) {
        if (this.yAxisLabel != null && !this.yAxisLabel.isEmpty()) {
            // REMARK/UNINTENDED: yAxisLabel may also be a resolved message (side-effect of StyledXYSeries#putMetadata),
            // and cannot be resolved, so we need to give the resolved value as default
            // TODO: In other implementations (i.e. FlowVelocityProcessor), an explicit (German) default label is given here,
            // probably the English version will also show German (CHECK)
            return generator.msg(this.yAxisLabel, this.yAxisLabel);
        }
        return generator.msg(this.i18n_axis_label, "MISSING");
    }

    protected static final Facet createFacet(final CallContext context, final String hash, final String id, final AbstractCalculationResult result,
            final int resultIndex, final String axisLabel, final String facetId, final String description) {
        final String facetFlowDepthFilteredDescription = Resources.getMsg(context.getMeta(), description, description, result.getLabel());
        return new ResultFacet(resultIndex, facetId, facetFlowDepthFilteredDescription, axisLabel, ComputeType.ADVANCE, id, hash);
    }
}