package ij.process;
import ij.IJ;
import ij.plugin.Colors;
import java.awt.image.*;
import java.awt.Color;

    /** This is an indexed color model that allows an
        lower and upper bound to be specified. */
    public class LUT extends IndexColorModel implements Cloneable {
        public static final String nameKey = "CurrentLUT";
        public double min, max;
        private IndexColorModel cm;
    
    /** Constructs a LUT from red, green and blue byte arrays, which must have a length of 256. */
    public LUT(byte r[], byte g[], byte b[]) {
        this(8, 256, r, g, b);
    }
    
    /** Constructs a LUT from red, green and blue byte arrays, where 'bits' 
        must be 8 and 'size' must be less than or equal to 256. */
    public LUT(int bits, int size, byte r[], byte g[], byte b[]) {
        super(bits, size, r, g, b);
    }
    
    public LUT(IndexColorModel cm, double min, double max) {
        super(8, cm.getMapSize(), getReds(cm), getGreens(cm), getBlues(cm));
        this.min = min;
        this.max = max;
    }
    
    static byte[] getReds(IndexColorModel cm) {
        byte[] reds=new byte[256]; cm.getReds(reds); return reds;
    }
    
    static byte[] getGreens(IndexColorModel cm) {
        byte[] greens=new byte[256]; cm.getGreens(greens); return greens;
    }
    
    static byte[] getBlues(IndexColorModel cm) {
        byte[] blues=new byte[256]; cm.getBlues(blues); return blues;
    }

    public IndexColorModel getColorModel() {
        if (cm==null) {
            byte[] reds=new byte[256]; getReds(reds);
            byte[] greens=new byte[256]; getGreens(greens);
            byte[] blues=new byte[256]; getBlues(blues);
            cm = new IndexColorModel(8, getMapSize(), reds, greens, blues);
        }
        return cm;
    }
        
    public byte[] getBytes() {
        int size = getMapSize();
        if (size!=256) return null;
        byte[] bytes = new byte[256*3];
        for (int i=0; i<256; i++) bytes[i] = (byte)getRed(i);
        for (int i=0; i<256; i++) bytes[256+i] = (byte)getGreen(i);
        for (int i=0; i<256; i++) bytes[512+i] = (byte)getBlue(i);
        return bytes;
    }
    
    public LUT createInvertedLut() {
        int mapSize = getMapSize();
        byte[] reds = new byte[mapSize];
        byte[] greens = new byte[mapSize];
        byte[] blues = new byte[mapSize];   
        byte[] reds2 = new byte[mapSize];
        byte[] greens2 = new byte[mapSize];
        byte[] blues2 = new byte[mapSize];  
        getReds(reds); 
        getGreens(greens); 
        getBlues(blues);
        for (int i=0; i<mapSize; i++) {
            reds2[i] = (byte)(reds[mapSize-i-1]&255);
            greens2[i] = (byte)(greens[mapSize-i-1]&255);
            blues2[i] = (byte)(blues[mapSize-i-1]&255);
        }
        return new LUT(8, mapSize, reds2, greens2, blues2);
    }
    
    /** Creates a color LUT from a Color. */
    public static LUT createLutFromColor(Color color) {
        byte[] rLut = new byte[256];
        byte[] gLut = new byte[256];
        byte[] bLut = new byte[256];
        int red = color.getRed();
        int green = color.getGreen();
        int blue = color.getBlue();
        double rIncr = ((double)red)/255d;
        double gIncr = ((double)green)/255d;
        double bIncr = ((double)blue)/255d;
        for (int i=0; i<256; ++i) {
            rLut[i] = (byte)(i*rIncr);
            gLut[i] = (byte)(i*gIncr);
            bLut[i] = (byte)(i*bIncr);
        }
        return new LUT(rLut, gLut, bLut);
    }

    public synchronized Object clone() {
        try {return super.clone();}
        catch (CloneNotSupportedException e) {return null;}
    }
    
    public  String toString() {
        return "rgb[0]="+Colors.colorToString(new Color(getRGB(0)))+", rgb[255]="
            +Colors.colorToString(new Color(getRGB(255)))+", min="+IJ.d2s(min,4)+", max="+IJ.d2s(max,4);
    }

}