/*
Copyright 2006 Jerry Huxtable

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package com.jhlabs.image;

import java.awt.*;
import java.awt.geom.*;
import java.awt.image.*;
import java.util.*;
import com.jhlabs.image.*;

public abstract class ImageUtils {
	
	public final static int SELECTED = 0xff000000;
	public final static int UNSELECTED = 0x00000000;
	
	public static BufferedImage backgroundImage = null;

	public static BufferedImage createImage(ImageProducer producer) {
		PixelGrabber pg = new PixelGrabber(producer, 0, 0, -1, -1, null, 0, 0);
		try {
			pg.grabPixels();
		} catch (InterruptedException e) {
			throw new RuntimeException("Image fetch interrupted");
		}
		if ((pg.status() & ImageObserver.ABORT) != 0)
			throw new RuntimeException("Image fetch aborted");
		if ((pg.status() & ImageObserver.ERROR) != 0)
			throw new RuntimeException("Image fetch error");
		BufferedImage p = new BufferedImage(pg.getWidth(), pg.getHeight(), BufferedImage.TYPE_INT_ARGB);
		p.setRGB(0, 0, pg.getWidth(), pg.getHeight(), (int[])pg.getPixels(), 0, pg.getWidth());
		return p;
	}
	
	/**
	 * Convert an Image into a TYPE_INT_ARGB BufferedImage. If the image is already of this type, the original image is returned unchanged.
	 */
	public static BufferedImage convertImageToARGB( Image image ) {
		if ( image instanceof BufferedImage && ((BufferedImage)image).getType() == BufferedImage.TYPE_INT_ARGB )
			return (BufferedImage)image;
		BufferedImage p = new BufferedImage( image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_ARGB);
		Graphics2D g = p.createGraphics();
		g.drawImage( image, 0, 0, null );
		g.dispose();
		return p;
	}
	
	// Returns a *copy* of a subimage of image. This avoids the performance problems associated with BufferedImage.getSubimage.
	public static BufferedImage getSubimage( BufferedImage image, int x, int y, int w, int h ) {
		BufferedImage newImage = new BufferedImage( w, h, BufferedImage.TYPE_INT_ARGB );
		Graphics2D g = newImage.createGraphics();
		g.drawRenderedImage( image, AffineTransform.getTranslateInstance(-x, -y) );
		g.dispose();
		return newImage;
	}

	public static BufferedImage cloneImage( BufferedImage image ) {
		BufferedImage newImage = new BufferedImage( image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB );
		Graphics2D g = newImage.createGraphics();
		g.drawRenderedImage( image, null );
		g.dispose();
		return newImage;
	}

	public static void paintCheckedBackground(Component c, Graphics g, int x, int y, int width, int height) {
		if ( backgroundImage == null ) {
			backgroundImage = new BufferedImage( 64, 64, BufferedImage.TYPE_INT_ARGB );
			Graphics bg = backgroundImage.createGraphics();
			for ( int by = 0; by < 64; by += 8 ) {
				for ( int bx = 0; bx < 64; bx += 8 ) {
					bg.setColor( ((bx^by) & 8) != 0 ? Color.lightGray : Color.white );
					bg.fillRect( bx, by, 8, 8 );
				}
			}
			bg.dispose();
		}

		if ( backgroundImage != null ) {
			Shape saveClip = g.getClip();
			Rectangle r = g.getClipBounds();
			if (r == null)
				r = new Rectangle(c.getSize());
			r = r.intersection(new Rectangle(x, y, width, height));
			g.setClip(r);
			int w = backgroundImage.getWidth();
			int h = backgroundImage.getHeight();
			if (w != -1 && h != -1) {
				int x1 = (r.x / w) * w;
				int y1 = (r.y / h) * h;
				int x2 = ((r.x + r.width + w - 1) / w) * w;
				int y2 = ((r.y + r.height + h - 1) / h) * h;
				for (y = y1; y < y2; y += h)
					for (x = x1; x < x2; x += w)
						g.drawImage(backgroundImage, x, y, c);
			}
			g.setClip(saveClip);
		}
	}

	public static Rectangle getSelectedBounds(BufferedImage p) {
		int width = p.getWidth();
        int height = p.getHeight();
		int maxX = 0, maxY = 0, minX = width, minY = height;
		boolean anySelected = false;
		int y1;
		int [] pixels = null;
		
		for (y1 = height-1; y1 >= 0; y1--) {
			pixels = getRGB( p, 0, y1, width, 1, pixels );
			for (int x = 0; x < minX; x++) {
				if ((pixels[x] & 0xff000000) != 0) {
					minX = x;
					maxY = y1;
					anySelected = true;
					break;
				}
			}
			for (int x = width-1; x >= maxX; x--) {
				if ((pixels[x] & 0xff000000) != 0) {
					maxX = x;
					maxY = y1;
					anySelected = true;
					break;
				}
			}
			if ( anySelected )
				break;
		}
		pixels = null;
		for (int y = 0; y < y1; y++) {
			pixels = getRGB( p, 0, y, width, 1, pixels );
			for (int x = 0; x < minX; x++) {
				if ((pixels[x] & 0xff000000) != 0) {
					minX = x;
					if ( y < minY )
						minY = y;
					anySelected = true;
					break;
				}
			}
			for (int x = width-1; x >= maxX; x--) {
				if ((pixels[x] & 0xff000000) != 0) {
					maxX = x;
					if ( y < minY )
						minY = y;
					anySelected = true;
					break;
				}
			}
		}
		if ( anySelected )
			return new Rectangle( minX, minY, maxX-minX+1, maxY-minY+1 );
		return null;
	}

	/**
	 * Compose src onto dst using the alpha of sel to interpolate between the two.
	 * I can't think of a way to do this using AlphaComposite.
	 */
	public static void composeThroughMask(Raster src, WritableRaster dst, Raster sel) {
		int x = src.getMinX();
		int y = src.getMinY();
		int w = src.getWidth();
		int h = src.getHeight();

		int srcRGB[] = null;
		int selRGB[] = null;
		int dstRGB[] = null;

		for ( int i = 0; i < h; i++ ) {
			srcRGB = src.getPixels(x, y, w, 1, srcRGB);
			selRGB = sel.getPixels(x, y, w, 1, selRGB);
			dstRGB = dst.getPixels(x, y, w, 1, dstRGB);

			int k = x;
			for ( int j = 0; j < w; j++ ) {
				int sr = srcRGB[k];
				int dir = dstRGB[k];
				int sg = srcRGB[k+1];
				int dig = dstRGB[k+1];
				int sb = srcRGB[k+2];
				int dib = dstRGB[k+2];
				int sa = srcRGB[k+3];
				int dia = dstRGB[k+3];

				float a = selRGB[k+3]/255f;
				float ac = 1-a;

				dstRGB[k] = (int)(a*sr + ac*dir); 
				dstRGB[k+1] = (int)(a*sg + ac*dig); 
				dstRGB[k+2] = (int)(a*sb + ac*dib); 
				dstRGB[k+3] = (int)(a*sa + ac*dia);
				k += 4;
			}

			dst.setPixels(x, y, w, 1, dstRGB);
			y++;
		}
	}

	/**
	 * A convenience method for getting ARGB pixels from an image. This tries to avoid the performance
	 * penalty of BufferedImage.getRGB unmanaging the image.
	 */
	public static int[] getRGB( BufferedImage image, int x, int y, int width, int height, int[] pixels ) {
		int type = image.getType();
		if ( type == BufferedImage.TYPE_INT_ARGB || type == BufferedImage.TYPE_INT_RGB )
			return (int [])image.getRaster().getDataElements( x, y, width, height, pixels );
		return image.getRGB( x, y, width, height, pixels, 0, width );
    }

	/**
	 * A convenience method for setting ARGB pixels in an image. This tries to avoid the performance
	 * penalty of BufferedImage.setRGB unmanaging the image.
	 */
	public static void setRGB( BufferedImage image, int x, int y, int width, int height, int[] pixels ) {
		int type = image.getType();
		if ( type == BufferedImage.TYPE_INT_ARGB || type == BufferedImage.TYPE_INT_RGB )
			image.getRaster().setDataElements( x, y, width, height, pixels );
		else
			image.setRGB( x, y, width, height, pixels, 0, width );
    }
}