/* Copyright (c) 2006 Yahoo! Inc. All rights reserved. */

YAHOO.util.Color = new function() {

    // Adapted from http://www.easyrgb.com/math.html
    // hsv values = 0 - 1
    // rgb values 0 - 255
    this.hsv2rgb = function (h, s, v) {
        var r, g, b;
        if ( s == 0 ) {
           r = v * 255;
           g = v * 255;
           b = v * 255;
        } else {

           // h must be < 1
           var var_h = h * 6;
           if ( var_h == 6 ) {
               var_h = 0;
           }

           //Or ... var_i = floor( var_h )
           var var_i = Math.floor( var_h );
           var var_1 = v * ( 1 - s );
           var var_2 = v * ( 1 - s * ( var_h - var_i ) );
           var var_3 = v * ( 1 - s * ( 1 - ( var_h - var_i ) ) );

           if ( var_i == 0 ) {
               var_r = v;
               var_g = var_3;
               var_b = var_1;
           } else if ( var_i == 1 ) {
               var_r = var_2;
               var_g = v;
               var_b = var_1;
           } else if ( var_i == 2 ) {
               var_r = var_1;
               var_g = v;
               var_b = var_3
           } else if ( var_i == 3 ) {
               var_r = var_1;
               var_g = var_2;
               var_b = v;
           } else if ( var_i == 4 ) {
               var_r = var_3;
               var_g = var_1;
               var_b = v;
           } else {
               var_r = v;
               var_g = var_1;
               var_b = var_2
           }

           r = var_r * 255                  //rgb results = 0 ÷ 255
           g = var_g * 255
           b = var_b * 255

           }
        return [Math.round(r), Math.round(g), Math.round(b)];
    };

    this.rgb2hsv = function (r,g,b)
    {
        var_R = (r / 255);
        var_G = (g / 255);
        var_B = (b / 255);

        var_Min = Math.min(var_R, var_G, var_B); //Min. value of RGB
        var_Max = Math.max(var_R, var_G, var_B); //Max. value of RGB
        del_Max = var_Max - var_Min;             //Delta RGB value

        v = var_Max;

        if(del_Max == 0) //This is a gray, no chroma...
        {
            h = 0;                                //HSV results = 0 ÷ 1
            s = 0;
        }
        else //Chromatic data...
        {
            s = del_Max / var_Max;

            del_R = (((var_Max - var_R) / 6 ) + (del_Max / 2)) / del_Max;
            del_G = (((var_Max - var_G) / 6 ) + (del_Max / 2)) / del_Max;
            del_B = (((var_Max - var_B) / 6 ) + (del_Max / 2)) / del_Max;

            if(var_R == var_Max)
                h = del_B - del_G;
            else if(var_G == var_Max)
                h = (1 / 3) + del_R - del_B;
            else if(var_B == var_Max)
                h = (2 / 3) + del_G - del_R;

            if(h < 0)
                h += 1;
            if(h > 1)
                h -= 1;
        }

        return [h, s, v];
    };

    this.rgb2hex = function (r,g,b) {
        return this.toHex(r) + this.toHex(g) + this.toHex(b);
    };

    this.hexchars = "0123456789ABCDEF";

    this.toHex = function(n) {
        n = n || 0;
        n = parseInt(n, 10);
        if (isNaN(n)) n = 0;
        n = Math.round(Math.min(Math.max(0, n), 255));

        return this.hexchars.charAt((n - n % 16) / 16) + this.hexchars.charAt(n % 16);
    };

    this.toDec = function(hexchar) {
        return this.hexchars.indexOf(hexchar.toUpperCase());
    };

    this.hex2rgb = function(str) {
        var rgb = [];
        rgb[0] = (this.toDec(str.substr(0, 1)) * 16) +
                        this.toDec(str.substr(1, 1));
        rgb[1] = (this.toDec(str.substr(2, 1)) * 16) +
                        this.toDec(str.substr(3, 1));
        rgb[2] = (this.toDec(str.substr(4, 1)) * 16) +
                        this.toDec(str.substr(5, 1));
        // gLogger.debug("hex2rgb: " + str + ", " + rgb.toString());
        return rgb;
    };

    this.isValidRGB = function(a) {
        if ((!a[0] && a[0] !=0) || isNaN(a[0]) || a[0] < 0 || a[0] > 255) return false;
        if ((!a[1] && a[1] !=0) || isNaN(a[1]) || a[1] < 0 || a[1] > 255) return false;
        if ((!a[2] && a[2] !=0) || isNaN(a[2]) || a[2] < 0 || a[2] > 255) return false;

        return true;
    };
}