/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2009, 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.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * --------------------------
 * DefaultHeatMapDataset.java
 * --------------------------
 * (C) Copyright 2009, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes:
 * --------
 * 28-Jan-2009 : Version 1 (DG);
 *
 */

package org.jfree.data.general;

import java.io.Serializable;
import org.jfree.data.DataUtilities;
import org.jfree.util.PublicCloneable;

/**
 * A default implementation of the {@link HeatMapDataset} interface.
 *
 * @since 1.0.13
 */
public class DefaultHeatMapDataset extends AbstractDataset
        implements HeatMapDataset, Cloneable, PublicCloneable, Serializable {

    /** The number of samples in this dataset for the x-dimension. */
    private int xSamples;

    /** The number of samples in this dataset for the y-dimension. */
    private int ySamples;

    /** The minimum x-value in the dataset. */
    private double minX;

    /** The maximum x-value in the dataset. */
    private double maxX;

    /** The minimum y-value in the dataset. */
    private double minY;

    /** The maximum y-value in the dataset. */
    private double maxY;

    /** Storage for the z-values. */
    private double[][] zValues;

    /**
     * Creates a new dataset where all the z-values are initially 0.  This is
     * a fixed size array of z-values.
     *
     * @param xSamples  the number of x-values.
     * @param ySamples  the number of y-values
     * @param minX  the minimum x-value in the dataset.
     * @param maxX  the maximum x-value in the dataset.
     * @param minY  the minimum y-value in the dataset.
     * @param maxY  the maximum y-value in the dataset.
     */
    public DefaultHeatMapDataset(int xSamples, int ySamples, double minX,
            double maxX, double minY, double maxY) {

        if (xSamples < 1) {
            throw new IllegalArgumentException("Requires 'xSamples' > 0");
        }
        if (ySamples < 1) {
            throw new IllegalArgumentException("Requires 'ySamples' > 0");
        }
        if (Double.isInfinite(minX) || Double.isNaN(minX)) {
            throw new IllegalArgumentException("'minX' cannot be INF or NaN.");
        }
        if (Double.isInfinite(maxX) || Double.isNaN(maxX)) {
            throw new IllegalArgumentException("'maxX' cannot be INF or NaN.");
        }
        if (Double.isInfinite(minY) || Double.isNaN(minY)) {
            throw new IllegalArgumentException("'minY' cannot be INF or NaN.");
        }
        if (Double.isInfinite(maxY) || Double.isNaN(maxY)) {
            throw new IllegalArgumentException("'maxY' cannot be INF or NaN.");
        }

        this.xSamples = xSamples;
        this.ySamples = ySamples;
        this.minX = minX;
        this.maxX = maxX;
        this.minY = minY;
        this.maxY = maxY;
        this.zValues = new double[xSamples][];
        for (int x = 0; x < xSamples; x++) {
            this.zValues[x] = new double[ySamples];
        }
    }

    /**
     * Returns the number of x values across the width of the dataset.  The
     * values are evenly spaced between {@link #getMinimumXValue()} and
     * {@link #getMaximumXValue()}.
     *
     * @return The number of x-values (always > 0).
     */
    public int getXSampleCount() {
        return this.xSamples;
    }

    /**
     * Returns the number of y values (or samples) for the dataset.  The
     * values are evenly spaced between {@link #getMinimumYValue()} and
     * {@link #getMaximumYValue()}.
     *
     * @return The number of y-values (always > 0).
     */
    public int getYSampleCount() {
        return this.ySamples;
    }

    /**
     * Returns the lowest x-value represented in this dataset.  A requirement
     * of this interface is that this method must never return infinite or
     * Double.NAN values.
     *
     * @return The lowest x-value represented in this dataset.
     */
    public double getMinimumXValue() {
        return this.minX;
    }

    /**
     * Returns the highest x-value represented in this dataset.  A requirement
     * of this interface is that this method must never return infinite or
     * Double.NAN values.
     *
     * @return The highest x-value represented in this dataset.
     */
    public double getMaximumXValue() {
        return this.maxX;
    }

    /**
     * Returns the lowest y-value represented in this dataset.  A requirement
     * of this interface is that this method must never return infinite or
     * Double.NAN values.
     *
     * @return The lowest y-value represented in this dataset.
     */
    public double getMinimumYValue() {
        return this.minY;
    }

    /**
     * Returns the highest y-value represented in this dataset.  A requirement
     * of this interface is that this method must never return infinite or
     * Double.NAN values.
     *
     * @return The highest y-value represented in this dataset.
     */
    public double getMaximumYValue() {
        return this.maxY;
    }

    /**
     * A convenience method that returns the x-value for the given index.
     *
     * @param xIndex  the xIndex.
     *
     * @return The x-value.
     */
    public double getXValue(int xIndex) {
        double x = this.minX
                + (this.maxX - this.minX) * (xIndex / (double) this.xSamples);
        return x;
    }

    /**
     * A convenience method that returns the y-value for the given index.
     *
     * @param yIndex  the yIndex.
     *
     * @return The y-value.
     */
    public double getYValue(int yIndex) {
        double y = this.minY
                + (this.maxY - this.minY) * (yIndex / (double) this.ySamples);
        return y;
    }

    /**
     * Returns the z-value at the specified sample position in the dataset.
     * For a missing or unknown value, this method should return Double.NAN.
     *
     * @param xIndex  the position of the x sample in the dataset.
     * @param yIndex  the position of the y sample in the dataset.
     *
     * @return The z-value.
     */
    public double getZValue(int xIndex, int yIndex) {
        return this.zValues[xIndex][yIndex];
    }

    /**
     * Returns the z-value at the specified sample position in the dataset.
     * In this implementation, where the underlying values are stored in an
     * array of double primitives, you should avoid using this method and
     * use {@link #getZValue(int, int)} instead.
     *
     * @param xIndex  the position of the x sample in the dataset.
     * @param yIndex  the position of the y sample in the dataset.
     *
     * @return The z-value.
     */
    public Number getZ(int xIndex, int yIndex) {
        return new Double(getZValue(xIndex, yIndex));
    }

    /**
     * Updates a z-value in the dataset and sends a {@link DatasetChangeEvent}
     * to all registered listeners.
     *
     * @param xIndex  the x-index.
     * @param yIndex  the y-index.
     * @param z  the new z-value.
     */
    public void setZValue(int xIndex, int yIndex, double z) {
        setZValue(xIndex, yIndex, z, true);
    }

    /**
     * Updates a z-value in the dataset and, if requested, sends a
     * {@link DatasetChangeEvent} to all registered listeners.
     *
     * @param xIndex  the x-index.
     * @param yIndex  the y-index.
     * @param z  the new z-value.
     * @param notify  notify listeners?
     */
    public void setZValue(int xIndex, int yIndex, double z, boolean notify) {
        this.zValues[xIndex][yIndex] = z;
        if (notify) {
            fireDatasetChanged();
        }
    }

    /**
     * Tests this dataset for equality with an arbitrary object.
     *
     * @param obj  the object (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof DefaultHeatMapDataset)) {
            return false;
        }
        DefaultHeatMapDataset that = (DefaultHeatMapDataset) obj;
        if (this.xSamples != that.xSamples) {
            return false;
        }
        if (this.ySamples != that.ySamples) {
            return false;
        }
        if (this.minX != that.minX) {
            return false;
        }
        if (this.maxX != that.maxX) {
            return false;
        }
        if (this.minY != that.minY) {
            return false;
        }
        if (this.maxY != that.maxY) {
            return false;
        }
        if (!DataUtilities.equal(this.zValues, that.zValues)) {
            return false;
        }
        // can't find any differences
        return true;
    }

    /**
     * Returns an independent copy of this dataset.
     *
     * @return A clone.
     *
     * @throws java.lang.CloneNotSupportedException
     */
    public Object clone() throws CloneNotSupportedException {
        DefaultHeatMapDataset clone = (DefaultHeatMapDataset) super.clone();
        clone.zValues = DataUtilities.clone(this.zValues);
        return clone;
    }

}
