/*
 * Copyright (c) 2010 by Intevation GmbH
 *
 * This program is free software under the LGPL (>=v2.1)
 * Read the file LGPL.txt coming with the software for details
 * or visit http://www.gnu.org/licenses/ if it does not exist.
 */

package de.intevation.gnv.chart;

import de.intevation.gnv.geobackend.base.Result;

import de.intevation.gnv.state.describedata.KeyValueDescibeData;

import java.awt.Color;

import java.awt.geom.Ellipse2D;

import java.text.NumberFormat;

import java.util.Collection;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;

import org.apache.log4j.Logger;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;

import org.jfree.chart.axis.Axis;
import org.jfree.chart.axis.AxisLocation;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.axis.NumberTickUnit;

import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;

import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;

import org.jfree.chart.title.TextTitle;

import org.jfree.data.Range;

import org.jfree.data.general.Series;

import org.jfree.data.xy.XYDataset;

import org.jfree.ui.RectangleInsets;

/**
 * This abstract class defines some methods to adjust chart settings after its
 * creation.
 *
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 */
public abstract class AbstractXYLineChart
extends               AbstractChart
{
    /**
     * Constant field used to expand the area between data and chart border. Its
     * value is {@value}.<br>
     * A value of 0.05 equals 5 percent.
     */
    public static final double LOWER_MARGIN = 0.05D;

    /**
     * Constant field used to expand the area between data and chart border. Its
     * value is {@value}.<br>
     * A value of 0.05 equals 5 percent.
     */
    public static final double UPPER_MARGIN = 0.05D;

    /**
     * Logger used to log with log4j.
     */
    private static Logger log      = Logger.getLogger(AbstractXYLineChart.class);

    /**
     * Field of supported colors used for lines and data points in charts.
     */
    protected static Color[] COLOR = {
        Color.black, Color.red, Color.green, Color.blue, Color.yellow,
        Color.gray, Color.orange, Color.pink, Color.cyan
    };

    /**
     * Static field to remember the index of the previously used color.
     */
    protected static int nextColor = 0;

    /**
     * Default <code>PlotOrientation</code>.
     */
    protected PlotOrientation PLOT_ORIENTATION = PlotOrientation.VERTICAL;

    /**
     * Map to store datasets for each parameter.
     */
    protected Map datasets;

    /**
     * Map to store max ranges of each parameter (axis.setAutoRange(true)
     * doesn't seem to work */
    protected Map ranges;

    /**
     * This method is called by <code>Chart</code> to bring the data into the
     * right form fitting to JFreeChart objects.
     */
    protected abstract void initData();

    /**
     * Add a value of <code>row</code> to <code>series</code>.
     *
     * @param row <code>Result</code> Object returned from database. Contains
     * a value used to add to <code>series</code>
     * @param series A JFreeChart Series object.
     */
    protected abstract void addValue(Result row, Series series);

    /**
     * Add <code>series</code> to JFreeChart's Dataset object currently which is
     * processing.
     *
     * @param series Series to add.
     * @param label Label used show in legend.
     * @param idx Currently not used.
     */
    protected abstract void addSeries(Series series, String label, int idx);

    /**
     * Abstract method which is called by <code>Chart</code> interface after
     * chart creation. It turns an axis' label into a locale specific format.
     *
     * @param axis Axis to adjust.
     * @param locale java.util.Locale object used specify the format.
     */
    protected abstract void localizeDomainAxis(Axis axis, Locale locale);

    /**
     * Abstract method to create a label for a series of parameters.
     *
     * @param breakPoint1 Identifier returned from database. These identifier
     * are used to identify the results from database which are all stored in
     * one big java.util.Collection.
     * @param breakPoint2 Identifier returned from database.
     * @param breakPoint3 Identifier returned from database.
     *
     * @return Concatinated string of parameter name and measurement.
     */
    protected abstract String createSeriesName(
        String breakPoint1,
        String breakPoint2,
        String breakPoint3
    );


    /**
     * @see de.intevation.gnv.chart.Chart#generateChart()
     */
    public JFreeChart generateChart() {
        log.debug("generate XYLineChart");
        nextColor = 0;

        if (chart != null)
            return chart;

        initChart();

        chart.addSubtitle(new TextTitle(labels.getSubtitle()));

        theme.apply(chart);
        initData();

        adjustPlot((XYPlot)chart.getPlot());

        return chart;
    }


    protected void initChart() {
        chart = ChartFactory.createXYLineChart(
            labels.getTitle(),
            labels.getDomainAxisLabel(),
            null,
            null,
            PLOT_ORIENTATION,
            true,
            false,
            false
        );
    }


    /**
     * Method used to adjust the axes after chart generation. Methods for i18n
     * support ({@link #localizeDomainAxis} and {@link #localizeRangeAxis}) are
     * called and axes of this series are expanded.
     *
     * @param seriesKey Identifier of an axis which have to be adjusted.
     * @param idx Set the axis identified by <code>seriesKey</code> to position
     * <code>idx</code>.
     */
    protected void prepareAxis(String seriesKey, int idx) {
        log.debug("prepare axis of xychart");

        XYPlot plot      = chart.getXYPlot();
        Axis xAxis       = plot.getDomainAxis();
        NumberAxis yAxis = new NumberAxis(seriesKey);

        localizeDomainAxis(xAxis, locale);
        localizeRangeAxis(yAxis, locale);

        // litte workarround to adjust the max range of axes.
        // NumberAxis.setAutoRange(true) doesn't seem to work properly.
        Range yRange = (Range) ranges.get(seriesKey);
        double lo    = yRange.getLowerBound();
        double hi    = yRange.getUpperBound();

        if (lo == hi) {
            yRange = new Range(
                lo - (lo / 100 * LOWER_MARGIN),
                hi + (hi / 100 * UPPER_MARGIN));
        }
        else {
            yRange = Range.expand(yRange, LOWER_MARGIN, UPPER_MARGIN);
        }
        yAxis.setRange(yRange);
        log.debug("Max Range of dataset is: " + yRange.toString());

        if (seriesKey.contains("richtung")) {
            yAxis.setTickUnit(new NumberTickUnit(30.0));
            yAxis.setUpperBound(360.0);
            yAxis.setLowerBound(0.0);
        }
        else {
            yAxis.setFixedDimension(10.0);
            yAxis.setAutoRangeIncludesZero(false);
        }

        plot.setRangeAxis(idx, yAxis);
        yAxis.configure();

        if (idx % 2 != 0)
            plot.setRangeAxisLocation(idx, AxisLocation.BOTTOM_OR_RIGHT);
        else
            plot.setRangeAxisLocation(idx, AxisLocation.BOTTOM_OR_LEFT);

        plot.mapDatasetToRangeAxis(idx, idx);
    }


    /**
     * Method to adjust the rendering of a series in a chart. Line color and
     * symbols of vertices are configured here.
     *
     * @param idx Position of the renderer.
     * @param seriesCount Maximum number of series in this chart.
     * @param renderLines Lines are displayed if true, otherwise they are not.
     * @param renderShapes Vertices are displayed if true, otherwise they are
     * not.
     */
    protected void adjustRenderer(
        int     idx,
        int     seriesCount,
        boolean renderLines,
        boolean renderShapes
    ) {
        log.debug("Adjust render of series");
        XYLineAndShapeRenderer renderer = null;
        XYPlot                 plot     = chart.getXYPlot();

        try {
            renderer = (XYLineAndShapeRenderer)((XYLineAndShapeRenderer)
                (plot.getRenderer())).clone();
        }
        catch (CloneNotSupportedException cnse) {
            log.warn("Error while cloning renderer.", cnse);
            renderer = new XYLineAndShapeRenderer(renderLines, renderShapes);
            renderer.setBaseShape(new Ellipse2D.Double(-2,-2,4,4));
        }

        for (int i = 0; i < seriesCount; i++) {
            renderer.setSeriesShape(i, renderer.getSeriesShape(0));
            renderer.setSeriesPaint(i, COLOR[nextColor() % COLOR.length]);
            renderer.setSeriesShapesVisible(i, renderShapes);
            renderer.setSeriesLinesVisible(i, renderLines);
        }
        plot.setRenderer(idx, renderer);
    }


    /**
     * @return Index of the next color
     */
    protected static synchronized int nextColor() {
        return nextColor++;
    }


    /**
     * Method to adjust the plot rendering. Disable horizontal grid lines if
     * <code>plot</code> contains only a single y-axis.
     *
     * @param plot JFreeChart Plot object to be adjusted.
     */
    protected void adjustPlot(XYPlot plot) {
        if (plot.getRangeAxisCount() > 1)
            plot.setRangeGridlinesVisible(false);

        plot.setAxisOffset(new RectangleInsets(0, 0, 0, 15));
    }


    /**
     * Abstract method which is called after chart creation. It turns an
     * axis' label into a locale specific format.
     *
     * @param axis Axis to adjust.
     * @param locale java.util.Locale object used specify the format.
     *
     */
    protected void localizeRangeAxis(Axis axis, Locale locale) {
        if (locale == null)
            return;

        log.debug(
            "Set language of axis [" + axis.getLabel() + "] " +
            "to " + locale.toString()
        );

        NumberFormat format = NumberFormat.getInstance(locale);
        ((NumberAxis) axis).setNumberFormatOverride(format);
    }


    /**
     * Return the maximum y-range of <code>dataset</code>.
     *
     * @param dataset Dataset to be scaned.
     *
     * @return JFreeChart Range object containing min and max y-value.
     */
    public Range getMaxRangeOfDataset(XYDataset dataset) {
        int    seriesCount = dataset.getSeriesCount();
        double upper       = Double.NEGATIVE_INFINITY;
        double lower       = Double.POSITIVE_INFINITY;

        for (int i = 0; i < seriesCount; i++) {
            int itemCount = dataset.getItemCount(i);

            for (int j = 0; j < itemCount; j++) {
                Number num = dataset.getY(i, j);

                if (num != null) {
                    double y = num.doubleValue();
                    lower    = y < lower ? y : lower;
                    upper    = y > upper ? y : upper;
                }
            }
        }

        return new Range(lower, upper);
    }


    /**
     * Return the maximum y-range of <code>dataset</code> with a margin of
     * <code>percent</code> percent.
     *
     * @param dataset Dataset to be scaned.
     * @param percent Percent used to expand the range.
     * @return JFreeChart Range object containing min and max y-value with a
     * margin.
     */
    public Range getMaxRangeOfDatasetWithMargin(
        XYDataset dataset,
        double    percent
    ) {
        Range range   = getMaxRangeOfDataset(dataset);
        double length = range.getLength();
        double upper  = range.getUpperBound() + length /100 * percent;
        double lower  = range.getLowerBound() - length /100 * percent;

        return new Range(lower, upper);
    }


    /**
     * Method to find a parameter specified by its value.
     *
     * @param label Search string.
     *
     * @return Value of a parameter with the given label.
     */
    protected String findParameter(String label) {
        Iterator iter = parameters.iterator();

        while (iter.hasNext()) {
            KeyValueDescibeData data = (KeyValueDescibeData) iter.next();
            String              key  = data.getValue();

            if (label.indexOf(key) > -1)
                return key;
        }

        return label;
    }


    /**
     * Method to find a description of a given collection of values.
     *
     * @param values Collection to be scaned.
     * @param id Identifier and search string of the searched value.
     *
     * @return title
     */
    protected String findValueTitle(Collection values, String id) {
        log.debug("find description of dataset");

        if (values != null){
            Iterator it = values.iterator();
            while (it.hasNext()) {
                KeyValueDescibeData data = (KeyValueDescibeData) it.next();

                if (id.equals(data.getKey()))
                    return data.getValue();
            }
        }
        return "";
    }


    /**
     * Method to store the maximum range. Since we need to adjust the range of
     * each range axis, we have to memorize its range - each parameter uses an
     * own range axis.
     *
     * @param ranges Map where ranges of each axis will be stored in.
     * @param value A given value on an axis.
     * @param parameter Parameter name which belongs to <code>value</code>.
     */
    protected void storeMaxRange(Map ranges, double value, String parameter) {
        Range  range     = null;

        range = ranges.containsKey(parameter)
            ? (Range) ranges.get(parameter)
            : new Range(value, value);

        double lower = range.getLowerBound();
        double upper = range.getUpperBound();

        lower = value < lower ? value : lower;
        upper = value > upper ? value : upper;

        ranges.put(parameter, new Range(lower, upper));
    }
}
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