package org.jzy3d.plot3d.rendering.legends;

import java.awt.image.BufferedImage;
import java.io.IOException;

import org.jzy3d.chart.ChartView;
import org.jzy3d.colors.Color;
import org.jzy3d.events.DrawableChangedEvent;
import org.jzy3d.events.IDrawableListener;
import org.jzy3d.io.FileImage;
import org.jzy3d.maths.Dimension;
import org.jzy3d.plot2d.primitive.AWTImageGenerator;
import org.jzy3d.plot3d.primitives.AbstractDrawable;
import org.jzy3d.plot3d.rendering.view.AWTImageViewport;

/**
 * A {@link AWTLegend} represent information concerning a
 * {@link AbstractDrawable} that may be displayed as a metadata in the
 * {@link ChartView}.
 * 
 * The constructor of a {@link AWTLegend} registers itself as listener of its
 * parent {@link AbstractDrawable}, and unregister itself when it is disposed.
 * 
 * When defining a concrete {@link AWTLegend}, one should:
 * 

 * 
override the {@link toImage(int width, int height)} method, that defines
 * the picture representation.
 * 
override the {@link drawableChanged(DrawableChangedEvent e)} method, that
 * must select events that actually triggers an image update.
 * 
 * 
 * Last, a {@link AWTLegend} optimizes rendering by :
 * 

 * 
storing current image dimension,
 * 
computing a new image only if the required {@link AWTLegend} dimensions
 * changed.
 * 
 * 
 * @author Martin Pernollet
 */
public abstract class AWTLegend extends AWTImageViewport implements IDrawableListener, ILegend {

    public AWTLegend(AbstractDrawable drawable) {
        this.drawable = drawable;
        if (drawable != null)
            drawable.addDrawableListener(this);
    }

    public AWTLegend(AbstractDrawable drawable, Color foreground, Color background) {
        this(drawable);
        this.foreground = foreground;
        this.background = background;
    }

    public void dispose() {
        if (drawable != null)
            drawable.removeDrawableListener(this);
    }

    public abstract BufferedImage toImage(int width, int height);

    /**
     * Defines viewport dimensions, and precompute an image if required (i.e. if
     * the viewport dimension have changed
     */
    @Override
    public void setViewPort(int width, int height, float left, float right) {
        super.setViewPort(width, height, left, right);

        int imgWidth = (int) (width * (right - left));

        if (imageWidth != imgWidth || imageHeight != height)
            setImage(toImage(imgWidth, height));
    }
    
    @Override
    public void drawableChanged(DrawableChangedEvent e) {
        if(e.what() == DrawableChangedEvent.FIELD_COLOR)
            updateImage();
    }


    @Override
    public void updateImage() {
        setImage(toImage(imageWidth, imageHeight));
    }

    public void saveImage(String filename) throws IOException {
        FileImage.savePNG(imageObj, filename);
    }
    
    
    @Override
    public Dimension getMinimumSize(){
        return minimumDimension;
    }
    
    public void setMinimumSize(Dimension dimension){
        minimumDimension = dimension;
    }
    
    public void setGeneratorColors() {
        if (foreground != null)
            imageGenerator.setForegroundColor(foreground);
        else
            imageGenerator.setForegroundColor(Color.BLACK);
        if (background != null) {
            imageGenerator.setBackgroundColor(background);
            imageGenerator.setHasBackground(true);
        } else
            imageGenerator.setHasBackground(false);
    }
    
    public Color getForeground() {
        return foreground;
    }

    public void setForeground(Color foreground) {
        this.foreground = foreground;
    }

    public Color getBackground() {
        return background;
    }

    public void setBackground(Color background) {
        this.background = background;
    }

    public Dimension getMinimumDimension() {
        return minimumDimension;
    }

    public void setMinimumDimension(Dimension minimumDimension) {
        this.minimumDimension = minimumDimension;
    }



    protected AbstractDrawable drawable;
    protected Color foreground;
    protected Color background;
    protected Dimension minimumDimension;
    protected AWTImageGenerator imageGenerator;
}