package ie.dcu.swt;

import java.awt.image.*;

import org.eclipse.swt.graphics.*;

/**
 * Converts SWT ImageData objects to BufferedImage objects and vice-versa.
 * 
 * @author Kevin McGuinness
 */
public class ImageConverter {
	
	public static BufferedImage convert(ImageData data) {
		ColorModel cm = null;
		PaletteData palette = data.palette;
		
		if (palette.isDirect) {
			cm = new DirectColorModel(
					data.depth, 
					palette.redMask, 
					palette.greenMask,
					palette.blueMask
			);
			
			WritableRaster raster = cm.createCompatibleWritableRaster(
					data.width, data.height);
			
			BufferedImage im = new BufferedImage(cm, raster, false, null);
			
			int[] pixels = new int[3];
			for (int y = 0; y < data.height; y++) {
				for (int x = 0; x < data.width; x++) {
					int pixel = data.getPixel(x, y);
					RGB rgb = palette.getRGB(pixel);
					pixels[0] = rgb.red;
					pixels[1] = rgb.green;
					pixels[2] = rgb.blue;
					raster.setPixels(x, y, 1, 1, pixels);
				}
			}
			return im;
			
		} else {
			
			RGB[] rgbs = palette.getRGBs();
			byte[] red = new byte[rgbs.length];
			byte[] green = new byte[rgbs.length];
			byte[] blue = new byte[rgbs.length];
			
			for (int i = 0; i < rgbs.length; i++) {
				RGB rgb = rgbs[i];
				red[i] = (byte) rgb.red;
				green[i] = (byte) rgb.green;
				blue[i] = (byte) rgb.blue;
			}
			
			if (data.transparentPixel != -1) {
				cm = new IndexColorModel(
						data.depth, 
						rgbs.length, 
						red, green, blue,
						data.transparentPixel
				);
				
			} else {
				cm = new IndexColorModel(
						data.depth, 
						rgbs.length, 
						red, green, blue
				);
			}
			
			WritableRaster raster = cm.createCompatibleWritableRaster(
					data.width, data.height);
			
			BufferedImage im = new BufferedImage(cm,
					raster, false, null);
			
			int[] pixels = new int[1];
			for (int y = 0; y < data.height; y++) {
				for (int x = 0; x < data.width; x++) {
					int pixel = data.getPixel(x, y);
					pixels[0] = pixel;
					raster.setPixel(x, y, pixels);
				}
			}
			
			return im;
		}
	}


	public static ImageData convertToSWT(BufferedImage im) {
		
		ColorModel cm = im.getColorModel();
		
		if (cm instanceof DirectColorModel) {
			DirectColorModel dcm = (DirectColorModel) cm;
			
			PaletteData palette = new PaletteData(
					dcm.getRedMask(), 
					dcm.getGreenMask(),
					dcm.getBlueMask()
			);
			
			ImageData data = new ImageData(
					im.getWidth(), im.getHeight(),
					dcm.getPixelSize(), palette
			);
			
			WritableRaster raster = im.getRaster();
			
			int[] pixels = new int[3];
			RGB rgb = new RGB(0,0,0);
			
			for (int y = 0; y < data.height; y++) {
				for (int x = 0; x < data.width; x++) {
					raster.getPixel(x, y, pixels);
					rgb.red   = pixels[0];
					rgb.green = pixels[1];
					rgb.blue  = pixels[2];
					int pixel = palette.getPixel(rgb);
					data.setPixel(x, y, pixel);
				}
			}
			
			return data;
			
			
		} else if (cm instanceof IndexColorModel) {
			IndexColorModel icm = (IndexColorModel) cm;
			
			int size = icm.getMapSize();
			byte[] reds = new byte[size];
			byte[] greens = new byte[size];
			byte[] blues = new byte[size];
			
			icm.getReds(reds);
			icm.getGreens(greens);
			icm.getBlues(blues);
			
			RGB[] rgbs = new RGB[size];
			for (int i = 0; i < rgbs.length; i++) {
				rgbs[i] = new RGB(reds[i] & 0xFF, greens[i] & 0xFF, blues[i] & 0xFF);
			}
			
			PaletteData palette = new PaletteData(rgbs);
			
			ImageData data = new ImageData(
					im.getWidth(), im.getHeight(),
					icm.getPixelSize(), palette
			);
			
			
			data.transparentPixel = icm.getTransparentPixel();
			WritableRaster raster = im.getRaster();
			
			int[] pixels = new int[1];
			for (int y = 0; y < data.height; y++) {
				for (int x = 0; x < data.width; x++) {
					raster.getPixel(x, y, pixels);
					data.setPixel(x, y, pixels[0]);
				}
			}
			
			return data;
		}
		
		return null;
	}
}