/*
*

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 railo.runtime.img.filter;import java.awt.Rectangle;
import java.awt.image.BufferedImage;

import railo.runtime.engine.ThreadLocalPageContext;
import railo.runtime.exp.FunctionException;
import railo.runtime.exp.PageException;
import railo.runtime.img.ImageUtil;
import railo.runtime.type.Struct;
import railo.runtime.type.util.CollectionUtil;

/**
 * A filter which removes noise from an image using a "pepper and salt" algorithm.
 */
public class DespeckleFilter extends WholeImageFilter  implements DynFiltering {

	public DespeckleFilter() {
	}

	private short pepperAndSalt( short c, short v1, short v2 ) {
		if ( c < v1 )
			c++;
		if ( c < v2 )
			c++;
		if ( c > v1 )
			c--;
		if ( c > v2 )
			c--;
		return c;
	}
	
	protected int[] filterPixels( int width, int height, int[] inPixels, Rectangle transformedSpace ) {
		int index = 0;
		short[][] r = new short[3][width];
		short[][] g = new short[3][width];
		short[][] b = new short[3][width];
		int[] outPixels = new int[width * height];

		for (int x = 0; x < width; x++) {
			int rgb = inPixels[x];
			r[1][x] = (short)((rgb >> 16) & 0xff);
			g[1][x] = (short)((rgb >> 8) & 0xff);
			b[1][x] = (short)(rgb & 0xff);
		}
		for (int y = 0; y < height; y++) {
			boolean yIn = y > 0 && y < height-1;
			int nextRowIndex = index+width;
			if ( y < height-1) {
				for (int x = 0; x < width; x++) {
					int rgb = inPixels[nextRowIndex++];
					r[2][x] = (short)((rgb >> 16) & 0xff);
					g[2][x] = (short)((rgb >> 8) & 0xff);
					b[2][x] = (short)(rgb & 0xff);
				}
			}
			for (int x = 0; x < width; x++) {
				boolean xIn = x > 0 && x < width-1;
				short or = r[1][x];
				short og = g[1][x];
				short ob = b[1][x];
				int w = x-1;
				int e = x+1;
				
				if ( yIn ) {
					or = pepperAndSalt( or, r[0][x], r[2][x] );
					og = pepperAndSalt( og, g[0][x], g[2][x] );
					ob = pepperAndSalt( ob, b[0][x], b[2][x] );
				}

				if ( xIn ) {
					or = pepperAndSalt( or, r[1][w], r[1][e] );
					og = pepperAndSalt( og, g[1][w], g[1][e] );
					ob = pepperAndSalt( ob, b[1][w], b[1][e] );
				}

				if ( yIn && xIn ) {
					or = pepperAndSalt( or, r[0][w], r[2][e] );
					og = pepperAndSalt( og, g[0][w], g[2][e] );
					ob = pepperAndSalt( ob, b[0][w], b[2][e] );

					or = pepperAndSalt( or, r[2][w], r[0][e] );
					og = pepperAndSalt( og, g[2][w], g[0][e] );
					ob = pepperAndSalt( ob, b[2][w], b[0][e] );
				}

				outPixels[index] = (inPixels[index] & 0xff000000) | (or << 16) | (og << 8) | ob;
				index++;
			}
			short[] t;
			t = r[0];
			r[0] = r[1];
			r[1] = r[2];
			r[2] = t;
			t = g[0];
			g[0] = g[1];
			g[1] = g[2];
			g[2] = t;
			t = b[0];
			b[0] = b[1];
			b[1] = b[2];
			b[2] = t;
		}
	
		return outPixels;
	}

	public String toString() {
		return "Blur/Despeckle...";
	}

	public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src);
		//Object o;

		// check for arguments not supported
		if(parameters.size()>0) {
			throw new FunctionException(ThreadLocalPageContext.get(), "ImageFilter", 3, "parameters", "the parameter"+(parameters.size()>1?"s":"")+" ["+CollectionUtil.getKeyList(parameters,", ")+"] "+(parameters.size()>1?"are":"is")+" not allowed, only the following parameters are supported []");
		}

		return filter(src, dst);
	}
}

