/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2014, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
 * Other names may be trademarks of their respective owners.]
 *
 * ------------------------
 * StackedAreaRenderer.java
 * ------------------------
 * (C) Copyright 2002-2014, by Dan Rivett (d.rivett@ukonline.co.uk) and
 *                          Contributors.
 *
 * Original Author:  Dan Rivett (adapted from AreaRenderer);
 * Contributor(s):   Jon Iles;
 *                   David Gilbert (for Object Refinery Limited);
 *                   Christian W. Zuckschwerdt;
 *                   Peter Kolb (patch 2511330);
 *
 * Changes:
 * --------
 * 20-Sep-2002 : Version 1, contributed by Dan Rivett;
 * 24-Oct-2002 : Amendments for changes in CategoryDataset interface and
 *               CategoryToolTipGenerator interface (DG);
 * 01-Nov-2002 : Added tooltips (DG);
 * 06-Nov-2002 : Renamed drawCategoryItem() --> drawItem() and now using axis
 *               for category spacing. Renamed StackedAreaCategoryItemRenderer
 *               --> StackedAreaRenderer (DG);
 * 26-Nov-2002 : Switched CategoryDataset --> TableDataset (DG);
 * 26-Nov-2002 : Replaced isStacked() method with getRangeType() method (DG);
 * 17-Jan-2003 : Moved plot classes to a separate package (DG);
 * 25-Mar-2003 : Implemented Serializable (DG);
 * 13-May-2003 : Modified to take into account the plot orientation (DG);
 * 30-Jul-2003 : Modified entity constructor (CZ);
 * 07-Oct-2003 : Added renderer state (DG);
 * 29-Apr-2004 : Added getRangeExtent() override (DG);
 * 05-Nov-2004 : Modified drawItem() signature (DG);
 * 07-Jan-2005 : Renamed getRangeExtent() --> findRangeBounds() (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 11-Oct-2006 : Added support for rendering data values as percentages,
 *               and added a second pass for drawing item labels (DG);
 * 04-Feb-2009 : Fixed support for hidden series, and bug in findRangeBounds()
 *               method for null dataset (PK/DG);
 * 04-Feb-2009 : Added item label support, and generate entities only in first
 *               pass (DG);
 * 04-Feb-2009 : Fixed bug for renderAsPercentages == true (DG);
 *
 */

package org.jfree.chart.renderer.category;

import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.data.DataUtilities;
import org.jfree.data.Range;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.general.DatasetUtilities;
import org.jfree.ui.RectangleEdge;
import org.jfree.util.PublicCloneable;

/**
 * A renderer that draws stacked area charts for a {@link CategoryPlot}.
 * The example shown here is generated by the
 * <code>StackedAreaChartDemo1.java</code> program included in the
 * JFreeChart Demo Collection:
 * <br><br>
 * <img src="../../../../../images/StackedAreaRendererSample.png"
 * alt="StackedAreaRendererSample.png">
 */
public class StackedAreaRenderer extends AreaRenderer
        implements Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -3595635038460823663L;

    /** A flag that controls whether the areas display values or percentages. */
    private boolean renderAsPercentages;

    /**
     * Creates a new renderer.
     */
    public StackedAreaRenderer() {
        this(false);
    }

    /**
     * Creates a new renderer.
     *
     * @param renderAsPercentages  a flag that controls whether the data values
     *                             are rendered as percentages.
     */
    public StackedAreaRenderer(boolean renderAsPercentages) {
        super();
        this.renderAsPercentages = renderAsPercentages;
    }

    /**
     * Returns <code>true</code> if the renderer displays each item value as
     * a percentage (so that the stacked areas add to 100%), and
     * <code>false</code> otherwise.
     *
     * @return A boolean.
     *
     * @since 1.0.3
     */
    public boolean getRenderAsPercentages() {
        return this.renderAsPercentages;
    }

    /**
     * Sets the flag that controls whether the renderer displays each item
     * value as a percentage (so that the stacked areas add to 100%), and sends
     * a {@link RendererChangeEvent} to all registered listeners.
     *
     * @param asPercentages  the flag.
     *
     * @since 1.0.3
     */
    public void setRenderAsPercentages(boolean asPercentages) {
        this.renderAsPercentages = asPercentages;
        fireChangeEvent();
    }

    /**
     * Returns the number of passes (<code>2</code>) required by this renderer.
     * The first pass is used to draw the areas, the second pass is used to
     * draw the item labels (if visible).
     *
     * @return The number of passes required by the renderer.
     */
    @Override
    public int getPassCount() {
        return 2;
    }

    /**
     * Returns the range of values the renderer requires to display all the
     * items from the specified dataset.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     *
     * @return The range (or <code>null</code> if the dataset is empty).
     */
    @Override
    public Range findRangeBounds(CategoryDataset dataset) {
        if (dataset == null) {
            return null;
        }
        if (this.renderAsPercentages) {
            return new Range(0.0, 1.0);
        }
        else {
            return DatasetUtilities.findStackedRangeBounds(dataset);
        }
    }

    /**
     * Draw a single data item.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param dataArea  the data plot area.
     * @param plot  the plot.
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     * @param dataset  the data.
     * @param row  the row index (zero-based).
     * @param column  the column index (zero-based).
     * @param pass  the pass index.
     */
    @Override
    public void drawItem(Graphics2D g2, CategoryItemRendererState state,
            Rectangle2D dataArea, CategoryPlot plot, CategoryAxis domainAxis,
            ValueAxis rangeAxis, CategoryDataset dataset, int row, int column,
            int pass) {

        if (!isSeriesVisible(row)) {
            return;
        }
        
        // setup for collecting optional entity info...
        Shape entityArea;
        EntityCollection entities = state.getEntityCollection();

        double y1 = 0.0;
        Number n = dataset.getValue(row, column);
        if (n != null) {
            y1 = n.doubleValue();
            if (this.renderAsPercentages) {
                double total = DataUtilities.calculateColumnTotal(dataset,
                        column, state.getVisibleSeriesArray());
                y1 = y1 / total;
            }
        }
        double[] stack1 = getStackValues(dataset, row, column,
                state.getVisibleSeriesArray());


        // leave the y values (y1, y0) untranslated as it is going to be be
        // stacked up later by previous series values, after this it will be
        // translated.
        double xx1 = domainAxis.getCategoryMiddle(column, getColumnCount(),
                dataArea, plot.getDomainAxisEdge());


        // get the previous point and the next point so we can calculate a
        // "hot spot" for the area (used by the chart entity)...
        double y0 = 0.0;
        n = dataset.getValue(row, Math.max(column - 1, 0));
        if (n != null) {
            y0 = n.doubleValue();
            if (this.renderAsPercentages) {
                double total = DataUtilities.calculateColumnTotal(dataset,
                        Math.max(column - 1, 0), state.getVisibleSeriesArray());
                y0 = y0 / total;
            }
        }
        double[] stack0 = getStackValues(dataset, row, Math.max(column - 1, 0),
                state.getVisibleSeriesArray());

        // FIXME: calculate xx0
        double xx0 = domainAxis.getCategoryStart(column, getColumnCount(),
                dataArea, plot.getDomainAxisEdge());

        int itemCount = dataset.getColumnCount();
        double y2 = 0.0;
        n = dataset.getValue(row, Math.min(column + 1, itemCount - 1));
        if (n != null) {
            y2 = n.doubleValue();
            if (this.renderAsPercentages) {
                double total = DataUtilities.calculateColumnTotal(dataset,
                        Math.min(column + 1, itemCount - 1),
                        state.getVisibleSeriesArray());
                y2 = y2 / total;
            }
        }
        double[] stack2 = getStackValues(dataset, row, Math.min(column + 1,
                itemCount - 1), state.getVisibleSeriesArray());

        double xx2 = domainAxis.getCategoryEnd(column, getColumnCount(),
                dataArea, plot.getDomainAxisEdge());

        // FIXME: calculate xxLeft and xxRight
        double xxLeft = xx0;
        double xxRight = xx2;

        double[] stackLeft = averageStackValues(stack0, stack1);
        double[] stackRight = averageStackValues(stack1, stack2);
        double[] adjStackLeft = adjustedStackValues(stack0, stack1);
        double[] adjStackRight = adjustedStackValues(stack1, stack2);

        float transY1;

        RectangleEdge edge1 = plot.getRangeAxisEdge();

        GeneralPath left = new GeneralPath();
        GeneralPath right = new GeneralPath();
        if (y1 >= 0.0) {  // handle positive value
            transY1 = (float) rangeAxis.valueToJava2D(y1 + stack1[1], dataArea,
                    edge1);
            float transStack1 = (float) rangeAxis.valueToJava2D(stack1[1],
                    dataArea, edge1);
            float transStackLeft = (float) rangeAxis.valueToJava2D(
                    adjStackLeft[1], dataArea, edge1);

            // LEFT POLYGON
            if (y0 >= 0.0) {
                double yleft = (y0 + y1) / 2.0 + stackLeft[1];
                float transYLeft
                    = (float) rangeAxis.valueToJava2D(yleft, dataArea, edge1);
                left.moveTo((float) xx1, transY1);
                left.lineTo((float) xx1, transStack1);
                left.lineTo((float) xxLeft, transStackLeft);
                left.lineTo((float) xxLeft, transYLeft);
                left.closePath();
            }
            else {
                left.moveTo((float) xx1, transStack1);
                left.lineTo((float) xx1, transY1);
                left.lineTo((float) xxLeft, transStackLeft);
                left.closePath();
            }

            float transStackRight = (float) rangeAxis.valueToJava2D(
                    adjStackRight[1], dataArea, edge1);
            // RIGHT POLYGON
            if (y2 >= 0.0) {
                double yright = (y1 + y2) / 2.0 + stackRight[1];
                float transYRight
                    = (float) rangeAxis.valueToJava2D(yright, dataArea, edge1);
                right.moveTo((float) xx1, transStack1);
                right.lineTo((float) xx1, transY1);
                right.lineTo((float) xxRight, transYRight);
                right.lineTo((float) xxRight, transStackRight);
                right.closePath();
            }
            else {
                right.moveTo((float) xx1, transStack1);
                right.lineTo((float) xx1, transY1);
                right.lineTo((float) xxRight, transStackRight);
                right.closePath();
            }
        }
        else {  // handle negative value
            transY1 = (float) rangeAxis.valueToJava2D(y1 + stack1[0], dataArea,
                    edge1);
            float transStack1 = (float) rangeAxis.valueToJava2D(stack1[0],
                    dataArea, edge1);
            float transStackLeft = (float) rangeAxis.valueToJava2D(
                    adjStackLeft[0], dataArea, edge1);

            // LEFT POLYGON
            if (y0 >= 0.0) {
                left.moveTo((float) xx1, transStack1);
                left.lineTo((float) xx1, transY1);
                left.lineTo((float) xxLeft, transStackLeft);
                left.clone();
            }
            else {
                double yleft = (y0 + y1) / 2.0 + stackLeft[0];
                float transYLeft = (float) rangeAxis.valueToJava2D(yleft,
                        dataArea, edge1);
                left.moveTo((float) xx1, transY1);
                left.lineTo((float) xx1, transStack1);
                left.lineTo((float) xxLeft, transStackLeft);
                left.lineTo((float) xxLeft, transYLeft);
                left.closePath();
            }
            float transStackRight = (float) rangeAxis.valueToJava2D(
                    adjStackRight[0], dataArea, edge1);

            // RIGHT POLYGON
            if (y2 >= 0.0) {
                right.moveTo((float) xx1, transStack1);
                right.lineTo((float) xx1, transY1);
                right.lineTo((float) xxRight, transStackRight);
                right.closePath();
            }
            else {
                double yright = (y1 + y2) / 2.0 + stackRight[0];
                float transYRight = (float) rangeAxis.valueToJava2D(yright,
                        dataArea, edge1);
                right.moveTo((float) xx1, transStack1);
                right.lineTo((float) xx1, transY1);
                right.lineTo((float) xxRight, transYRight);
                right.lineTo((float) xxRight, transStackRight);
                right.closePath();
            }
        }

        if (pass == 0) {
            Paint itemPaint = getItemPaint(row, column);
            g2.setPaint(itemPaint);
            g2.fill(left);
            g2.fill(right);

            // add an entity for the item...
            if (entities != null) {
                GeneralPath gp = new GeneralPath(left);
                gp.append(right, false);
                entityArea = gp;
                addItemEntity(entities, dataset, row, column, entityArea);
            }
        }
        else if (pass == 1) {
            drawItemLabel(g2, plot.getOrientation(), dataset, row, column,
                    xx1, transY1, y1 < 0.0);
        }

    }

    /**
     * Calculates the stacked values (one positive and one negative) of all
     * series up to, but not including, <code>series</code> for the specified
     * item. It returns [0.0, 0.0] if <code>series</code> is the first series.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param series  the series index.
     * @param index  the item index.
     * @param validRows  the valid rows.
     *
     * @return An array containing the cumulative negative and positive values
     *     for all series values up to but excluding <code>series</code>
     *     for <code>index</code>.
     */
    protected double[] getStackValues(CategoryDataset dataset,
            int series, int index, int[] validRows) {
        double[] result = new double[2];
        double total = 0.0;
        if (this.renderAsPercentages) {
            total = DataUtilities.calculateColumnTotal(dataset, index, 
                    validRows);
        }
        for (int i = 0; i < series; i++) {
            if (isSeriesVisible(i)) {
                double v = 0.0;
                Number n = dataset.getValue(i, index);
                if (n != null) {
                    v = n.doubleValue();
                    if (this.renderAsPercentages) {
                        v = v / total;
                    }
                }
                if (!Double.isNaN(v)) {
                    if (v >= 0.0) {
                        result[1] += v;
                    }
                    else {
                        result[0] += v;
                    }
                }
            }
        }
        return result;
    }

    /**
     * Returns a pair of "stack" values calculated as the mean of the two
     * specified stack value pairs.
     *
     * @param stack1  the first stack pair.
     * @param stack2  the second stack pair.
     *
     * @return A pair of average stack values.
     */
    private double[] averageStackValues(double[] stack1, double[] stack2) {
        double[] result = new double[2];
        result[0] = (stack1[0] + stack2[0]) / 2.0;
        result[1] = (stack1[1] + stack2[1]) / 2.0;
        return result;
    }

    /**
     * Calculates adjusted stack values from the supplied values.  The value is
     * the mean of the supplied values, unless either of the supplied values
     * is zero, in which case the adjusted value is zero also.
     *
     * @param stack1  the first stack pair.
     * @param stack2  the second stack pair.
     *
     * @return A pair of average stack values.
     */
    private double[] adjustedStackValues(double[] stack1, double[] stack2) {
        double[] result = new double[2];
        if (stack1[0] == 0.0 || stack2[0] == 0.0) {
            result[0] = 0.0;
        }
        else {
            result[0] = (stack1[0] + stack2[0]) / 2.0;
        }
        if (stack1[1] == 0.0 || stack2[1] == 0.0) {
            result[1] = 0.0;
        }
        else {
            result[1] = (stack1[1] + stack2[1]) / 2.0;
        }
        return result;
    }

    /**
     * Checks this instance for equality with an arbitrary object.
     *
     * @param obj  the object (<code>null</code> not permitted).
     *
     * @return A boolean.
     */
    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof StackedAreaRenderer)) {
            return false;
        }
        StackedAreaRenderer that = (StackedAreaRenderer) obj;
        if (this.renderAsPercentages != that.renderAsPercentages) {
            return false;
        }
        return super.equals(obj);
    }

    /**
     * Calculates the stacked value of the all series up to, but not including
     * <code>series</code> for the specified category, <code>category</code>.
     * It returns 0.0 if <code>series</code> is the first series, i.e. 0.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param series  the series.
     * @param category  the category.
     *
     * @return double returns a cumulative value for all series' values up to
     *         but excluding <code>series</code> for Object
     *         <code>category</code>.
     *
     * @deprecated As of 1.0.13, as the method is never used internally.
     */
    protected double getPreviousHeight(CategoryDataset dataset,
            int series, int category) {

        double result = 0.0;
        Number n;
        double total = 0.0;
        if (this.renderAsPercentages) {
            total = DataUtilities.calculateColumnTotal(dataset, category);
        }
        for (int i = 0; i < series; i++) {
            n = dataset.getValue(i, category);
            if (n != null) {
                double v = n.doubleValue();
                if (this.renderAsPercentages) {
                    v = v / total;
                }
                result += v;
            }
        }
        return result;

    }

}