/* MIT license */ var cssKeywords = require('color-name');

// NOTE: conversions should only return primitive values (i.e. arrays, or // values that give correct `typeof` results). // do not use box values types (i.e. Number(), String(), etc.)

var reverseKeywords = {}; for (var key in cssKeywords) {

if (cssKeywords.hasOwnProperty(key)) {
        reverseKeywords[cssKeywords[key]] = key;
}

}

var convert = module.exports = {

rgb: {channels: 3, labels: 'rgb'},
hsl: {channels: 3, labels: 'hsl'},
hsv: {channels: 3, labels: 'hsv'},
hwb: {channels: 3, labels: 'hwb'},
cmyk: {channels: 4, labels: 'cmyk'},
xyz: {channels: 3, labels: 'xyz'},
lab: {channels: 3, labels: 'lab'},
lch: {channels: 3, labels: 'lch'},
hex: {channels: 1, labels: ['hex']},
keyword: {channels: 1, labels: ['keyword']},
ansi16: {channels: 1, labels: ['ansi16']},
ansi256: {channels: 1, labels: ['ansi256']},
hcg: {channels: 3, labels: ['h', 'c', 'g']},
apple: {channels: 3, labels: ['r16', 'g16', 'b16']},
gray: {channels: 1, labels: ['gray']}

};

// hide .channels and .labels properties for (var model in convert) {

if (convert.hasOwnProperty(model)) {
        if (!('channels' in convert[model])) {
                throw new Error('missing channels property: ' + model);
        }

        if (!('labels' in convert[model])) {
                throw new Error('missing channel labels property: ' + model);
        }

        if (convert[model].labels.length !== convert[model].channels) {
                throw new Error('channel and label counts mismatch: ' + model);
        }

        var channels = convert[model].channels;
        var labels = convert[model].labels;
        delete convert[model].channels;
        delete convert[model].labels;
        Object.defineProperty(convert[model], 'channels', {value: channels});
        Object.defineProperty(convert[model], 'labels', {value: labels});
}

}

convert.rgb.hsl = function (rgb) {

var r = rgb[0] / 255;
var g = rgb[1] / 255;
var b = rgb[2] / 255;
var min = Math.min(r, g, b);
var max = Math.max(r, g, b);
var delta = max - min;
var h;
var s;
var l;

if (max === min) {
        h = 0;
} else if (r === max) {
        h = (g - b) / delta;
} else if (g === max) {
        h = 2 + (b - r) / delta;
} else if (b === max) {
        h = 4 + (r - g) / delta;
}

h = Math.min(h * 60, 360);

if (h < 0) {
        h += 360;
}

l = (min + max) / 2;

if (max === min) {
        s = 0;
} else if (l <= 0.5) {
        s = delta / (max + min);
} else {
        s = delta / (2 - max - min);
}

return [h, s * 100, l * 100];

};

convert.rgb.hsv = function (rgb) {

var rdif;
var gdif;
var bdif;
var h;
var s;

var r = rgb[0] / 255;
var g = rgb[1] / 255;
var b = rgb[2] / 255;
var v = Math.max(r, g, b);
var diff = v - Math.min(r, g, b);
var diffc = function (c) {
        return (v - c) / 6 / diff + 1 / 2;
};

if (diff === 0) {
        h = s = 0;
} else {
        s = diff / v;
        rdif = diffc(r);
        gdif = diffc(g);
        bdif = diffc(b);

        if (r === v) {
                h = bdif - gdif;
        } else if (g === v) {
                h = (1 / 3) + rdif - bdif;
        } else if (b === v) {
                h = (2 / 3) + gdif - rdif;
        }
        if (h < 0) {
                h += 1;
        } else if (h > 1) {
                h -= 1;
        }
}

return [
        h * 360,
        s * 100,
        v * 100
];

};

convert.rgb.hwb = function (rgb) {

var r = rgb[0];
var g = rgb[1];
var b = rgb[2];
var h = convert.rgb.hsl(rgb)[0];
var w = 1 / 255 * Math.min(r, Math.min(g, b));

b = 1 - 1 / 255 * Math.max(r, Math.max(g, b));

return [h, w * 100, b * 100];

};

convert.rgb.cmyk = function (rgb) {

var r = rgb[0] / 255;
var g = rgb[1] / 255;
var b = rgb[2] / 255;
var c;
var m;
var y;
var k;

k = Math.min(1 - r, 1 - g, 1 - b);
c = (1 - r - k) / (1 - k) || 0;
m = (1 - g - k) / (1 - k) || 0;
y = (1 - b - k) / (1 - k) || 0;

return [c * 100, m * 100, y * 100, k * 100];

};

/**

* See https://en.m.wikipedia.org/wiki/Euclidean_distance#Squared_Euclidean_distance
* */

function comparativeDistance(x, y) {

return (
        Math.pow(x[0] - y[0], 2) +
        Math.pow(x[1] - y[1], 2) +
        Math.pow(x[2] - y[2], 2)
);

}

convert.rgb.keyword = function (rgb) {

var reversed = reverseKeywords[rgb];
if (reversed) {
        return reversed;
}

var currentClosestDistance = Infinity;
var currentClosestKeyword;

for (var keyword in cssKeywords) {
        if (cssKeywords.hasOwnProperty(keyword)) {
                var value = cssKeywords[keyword];

                // Compute comparative distance
                var distance = comparativeDistance(rgb, value);

                // Check if its less, if so set as closest
                if (distance < currentClosestDistance) {
                        currentClosestDistance = distance;
                        currentClosestKeyword = keyword;
                }
        }
}

return currentClosestKeyword;

};

convert.keyword.rgb = function (keyword) {

return cssKeywords[keyword];

};

convert.rgb.xyz = function (rgb) {

var r = rgb[0] / 255;
var g = rgb[1] / 255;
var b = rgb[2] / 255;

// assume sRGB
r = r > 0.04045 ? Math.pow(((r + 0.055) / 1.055), 2.4) : (r / 12.92);
g = g > 0.04045 ? Math.pow(((g + 0.055) / 1.055), 2.4) : (g / 12.92);
b = b > 0.04045 ? Math.pow(((b + 0.055) / 1.055), 2.4) : (b / 12.92);

var x = (r * 0.4124) + (g * 0.3576) + (b * 0.1805);
var y = (r * 0.2126) + (g * 0.7152) + (b * 0.0722);
var z = (r * 0.0193) + (g * 0.1192) + (b * 0.9505);

return [x * 100, y * 100, z * 100];

};

convert.rgb.lab = function (rgb) {

var xyz = convert.rgb.xyz(rgb);
var x = xyz[0];
var y = xyz[1];
var z = xyz[2];
var l;
var a;
var b;

x /= 95.047;
y /= 100;
z /= 108.883;

x = x > 0.008856 ? Math.pow(x, 1 / 3) : (7.787 * x) + (16 / 116);
y = y > 0.008856 ? Math.pow(y, 1 / 3) : (7.787 * y) + (16 / 116);
z = z > 0.008856 ? Math.pow(z, 1 / 3) : (7.787 * z) + (16 / 116);

l = (116 * y) - 16;
a = 500 * (x - y);
b = 200 * (y - z);

return [l, a, b];

};

convert.hsl.rgb = function (hsl) {

var h = hsl[0] / 360;
var s = hsl[1] / 100;
var l = hsl[2] / 100;
var t1;
var t2;
var t3;
var rgb;
var val;

if (s === 0) {
        val = l * 255;
        return [val, val, val];
}

if (l < 0.5) {
        t2 = l * (1 + s);
} else {
        t2 = l + s - l * s;
}

t1 = 2 * l - t2;

rgb = [0, 0, 0];
for (var i = 0; i < 3; i++) {
        t3 = h + 1 / 3 * -(i - 1);
        if (t3 < 0) {
                t3++;
        }
        if (t3 > 1) {
                t3--;
        }

        if (6 * t3 < 1) {
                val = t1 + (t2 - t1) * 6 * t3;
        } else if (2 * t3 < 1) {
                val = t2;
        } else if (3 * t3 < 2) {
                val = t1 + (t2 - t1) * (2 / 3 - t3) * 6;
        } else {
                val = t1;
        }

        rgb[i] = val * 255;
}

return rgb;

};

convert.hsl.hsv = function (hsl) {

var h = hsl[0];
var s = hsl[1] / 100;
var l = hsl[2] / 100;
var smin = s;
var lmin = Math.max(l, 0.01);
var sv;
var v;

l *= 2;
s *= (l <= 1) ? l : 2 - l;
smin *= lmin <= 1 ? lmin : 2 - lmin;
v = (l + s) / 2;
sv = l === 0 ? (2 * smin) / (lmin + smin) : (2 * s) / (l + s);

return [h, sv * 100, v * 100];

};

convert.hsv.rgb = function (hsv) {

var h = hsv[0] / 60;
var s = hsv[1] / 100;
var v = hsv[2] / 100;
var hi = Math.floor(h) % 6;

var f = h - Math.floor(h);
var p = 255 * v * (1 - s);
var q = 255 * v * (1 - (s * f));
var t = 255 * v * (1 - (s * (1 - f)));
v *= 255;

switch (hi) {
        case 0:
                return [v, t, p];
        case 1:
                return [q, v, p];
        case 2:
                return [p, v, t];
        case 3:
                return [p, q, v];
        case 4:
                return [t, p, v];
        case 5:
                return [v, p, q];
}

};

convert.hsv.hsl = function (hsv) {

var h = hsv[0];
var s = hsv[1] / 100;
var v = hsv[2] / 100;
var vmin = Math.max(v, 0.01);
var lmin;
var sl;
var l;

l = (2 - s) * v;
lmin = (2 - s) * vmin;
sl = s * vmin;
sl /= (lmin <= 1) ? lmin : 2 - lmin;
sl = sl || 0;
l /= 2;

return [h, sl * 100, l * 100];

};

// dev.w3.org/csswg/css-color/#hwb-to-rgb convert.hwb.rgb = function (hwb) {

var h = hwb[0] / 360;
var wh = hwb[1] / 100;
var bl = hwb[2] / 100;
var ratio = wh + bl;
var i;
var v;
var f;
var n;

// wh + bl cant be > 1
if (ratio > 1) {
        wh /= ratio;
        bl /= ratio;
}

i = Math.floor(6 * h);
v = 1 - bl;
f = 6 * h - i;

if ((i & 0x01) !== 0) {
        f = 1 - f;
}

n = wh + f * (v - wh); // linear interpolation

var r;
var g;
var b;
switch (i) {
        default:
        case 6:
        case 0: r = v; g = n; b = wh; break;
        case 1: r = n; g = v; b = wh; break;
        case 2: r = wh; g = v; b = n; break;
        case 3: r = wh; g = n; b = v; break;
        case 4: r = n; g = wh; b = v; break;
        case 5: r = v; g = wh; b = n; break;
}

return [r * 255, g * 255, b * 255];

};

convert.cmyk.rgb = function (cmyk) {

var c = cmyk[0] / 100;
var m = cmyk[1] / 100;
var y = cmyk[2] / 100;
var k = cmyk[3] / 100;
var r;
var g;
var b;

r = 1 - Math.min(1, c * (1 - k) + k);
g = 1 - Math.min(1, m * (1 - k) + k);
b = 1 - Math.min(1, y * (1 - k) + k);

return [r * 255, g * 255, b * 255];

};

convert.xyz.rgb = function (xyz) {

var x = xyz[0] / 100;
var y = xyz[1] / 100;
var z = xyz[2] / 100;
var r;
var g;
var b;

r = (x * 3.2406) + (y * -1.5372) + (z * -0.4986);
g = (x * -0.9689) + (y * 1.8758) + (z * 0.0415);
b = (x * 0.0557) + (y * -0.2040) + (z * 1.0570);

// assume sRGB
r = r > 0.0031308
        ? ((1.055 * Math.pow(r, 1.0 / 2.4)) - 0.055)
        : r * 12.92;

g = g > 0.0031308
        ? ((1.055 * Math.pow(g, 1.0 / 2.4)) - 0.055)
        : g * 12.92;

b = b > 0.0031308
        ? ((1.055 * Math.pow(b, 1.0 / 2.4)) - 0.055)
        : b * 12.92;

r = Math.min(Math.max(0, r), 1);
g = Math.min(Math.max(0, g), 1);
b = Math.min(Math.max(0, b), 1);

return [r * 255, g * 255, b * 255];

};

convert.xyz.lab = function (xyz) {

var x = xyz[0];
var y = xyz[1];
var z = xyz[2];
var l;
var a;
var b;

x /= 95.047;
y /= 100;
z /= 108.883;

x = x > 0.008856 ? Math.pow(x, 1 / 3) : (7.787 * x) + (16 / 116);
y = y > 0.008856 ? Math.pow(y, 1 / 3) : (7.787 * y) + (16 / 116);
z = z > 0.008856 ? Math.pow(z, 1 / 3) : (7.787 * z) + (16 / 116);

l = (116 * y) - 16;
a = 500 * (x - y);
b = 200 * (y - z);

return [l, a, b];

};

convert.lab.xyz = function (lab) {

var l = lab[0];
var a = lab[1];
var b = lab[2];
var x;
var y;
var z;

y = (l + 16) / 116;
x = a / 500 + y;
z = y - b / 200;

var y2 = Math.pow(y, 3);
var x2 = Math.pow(x, 3);
var z2 = Math.pow(z, 3);
y = y2 > 0.008856 ? y2 : (y - 16 / 116) / 7.787;
x = x2 > 0.008856 ? x2 : (x - 16 / 116) / 7.787;
z = z2 > 0.008856 ? z2 : (z - 16 / 116) / 7.787;

x *= 95.047;
y *= 100;
z *= 108.883;

return [x, y, z];

};

convert.lab.lch = function (lab) {

var l = lab[0];
var a = lab[1];
var b = lab[2];
var hr;
var h;
var c;

hr = Math.atan2(b, a);
h = hr * 360 / 2 / Math.PI;

if (h < 0) {
        h += 360;
}

c = Math.sqrt(a * a + b * b);

return [l, c, h];

};

convert.lch.lab = function (lch) {

var l = lch[0];
var c = lch[1];
var h = lch[2];
var a;
var b;
var hr;

hr = h / 360 * 2 * Math.PI;
a = c * Math.cos(hr);
b = c * Math.sin(hr);

return [l, a, b];

};

convert.rgb.ansi16 = function (args) {

var r = args[0];
var g = args[1];
var b = args[2];
var value = 1 in arguments ? arguments[1] : convert.rgb.hsv(args)[2]; // hsv -> ansi16 optimization

value = Math.round(value / 50);

if (value === 0) {
        return 30;
}

var ansi = 30
        + ((Math.round(b / 255) << 2)
        | (Math.round(g / 255) << 1)
        | Math.round(r / 255));

if (value === 2) {
        ansi += 60;
}

return ansi;

};

convert.hsv.ansi16 = function (args) {

// optimization here; we already know the value and don't need to get
// it converted for us.
return convert.rgb.ansi16(convert.hsv.rgb(args), args[2]);

};

convert.rgb.ansi256 = function (args) {

var r = args[0];
var g = args[1];
var b = args[2];

// we use the extended greyscale palette here, with the exception of
// black and white. normal palette only has 4 greyscale shades.
if (r === g && g === b) {
        if (r < 8) {
                return 16;
        }

        if (r > 248) {
                return 231;
        }

        return Math.round(((r - 8) / 247) * 24) + 232;
}

var ansi = 16
        + (36 * Math.round(r / 255 * 5))
        + (6 * Math.round(g / 255 * 5))
        + Math.round(b / 255 * 5);

return ansi;

};

convert.ansi16.rgb = function (args) {

var color = args % 10;

// handle greyscale
if (color === 0 || color === 7) {
        if (args > 50) {
                color += 3.5;
        }

        color = color / 10.5 * 255;

        return [color, color, color];
}

var mult = (~~(args > 50) + 1) * 0.5;
var r = ((color & 1) * mult) * 255;
var g = (((color >> 1) & 1) * mult) * 255;
var b = (((color >> 2) & 1) * mult) * 255;

return [r, g, b];

};

convert.ansi256.rgb = function (args) {

// handle greyscale
if (args >= 232) {
        var c = (args - 232) * 10 + 8;
        return [c, c, c];
}

args -= 16;

var rem;
var r = Math.floor(args / 36) / 5 * 255;
var g = Math.floor((rem = args % 36) / 6) / 5 * 255;
var b = (rem % 6) / 5 * 255;

return [r, g, b];

};

convert.rgb.hex = function (args) {

var integer = ((Math.round(args[0]) & 0xFF) << 16)
        + ((Math.round(args[1]) & 0xFF) << 8)
        + (Math.round(args[2]) & 0xFF);

var string = integer.toString(16).toUpperCase();
return '000000'.substring(string.length) + string;

};

convert.hex.rgb = function (args) {

var match = args.toString(16).match(/[a-f0-9]{6}|[a-f0-9]{3}/i);
if (!match) {
        return [0, 0, 0];
}

var colorString = match[0];

if (match[0].length === 3) {
        colorString = colorString.split('').map(function (char) {
                return char + char;
        }).join('');
}

var integer = parseInt(colorString, 16);
var r = (integer >> 16) & 0xFF;
var g = (integer >> 8) & 0xFF;
var b = integer & 0xFF;

return [r, g, b];

};

convert.rgb.hcg = function (rgb) {

var r = rgb[0] / 255;
var g = rgb[1] / 255;
var b = rgb[2] / 255;
var max = Math.max(Math.max(r, g), b);
var min = Math.min(Math.min(r, g), b);
var chroma = (max - min);
var grayscale;
var hue;

if (chroma < 1) {
        grayscale = min / (1 - chroma);
} else {
        grayscale = 0;
}

if (chroma <= 0) {
        hue = 0;
} else
if (max === r) {
        hue = ((g - b) / chroma) % 6;
} else
if (max === g) {
        hue = 2 + (b - r) / chroma;
} else {
        hue = 4 + (r - g) / chroma + 4;
}

hue /= 6;
hue %= 1;

return [hue * 360, chroma * 100, grayscale * 100];

};

convert.hsl.hcg = function (hsl) {

var s = hsl[1] / 100;
var l = hsl[2] / 100;
var c = 1;
var f = 0;

if (l < 0.5) {
        c = 2.0 * s * l;
} else {
        c = 2.0 * s * (1.0 - l);
}

if (c < 1.0) {
        f = (l - 0.5 * c) / (1.0 - c);
}

return [hsl[0], c * 100, f * 100];

};

convert.hsv.hcg = function (hsv) {

var s = hsv[1] / 100;
var v = hsv[2] / 100;

var c = s * v;
var f = 0;

if (c < 1.0) {
        f = (v - c) / (1 - c);
}

return [hsv[0], c * 100, f * 100];

};

convert.hcg.rgb = function (hcg) {

var h = hcg[0] / 360;
var c = hcg[1] / 100;
var g = hcg[2] / 100;

if (c === 0.0) {
        return [g * 255, g * 255, g * 255];
}

var pure = [0, 0, 0];
var hi = (h % 1) * 6;
var v = hi % 1;
var w = 1 - v;
var mg = 0;

switch (Math.floor(hi)) {
        case 0:
                pure[0] = 1; pure[1] = v; pure[2] = 0; break;
        case 1:
                pure[0] = w; pure[1] = 1; pure[2] = 0; break;
        case 2:
                pure[0] = 0; pure[1] = 1; pure[2] = v; break;
        case 3:
                pure[0] = 0; pure[1] = w; pure[2] = 1; break;
        case 4:
                pure[0] = v; pure[1] = 0; pure[2] = 1; break;
        default:
                pure[0] = 1; pure[1] = 0; pure[2] = w;
}

mg = (1.0 - c) * g;

return [
        (c * pure[0] + mg) * 255,
        (c * pure[1] + mg) * 255,
        (c * pure[2] + mg) * 255
];

};

convert.hcg.hsv = function (hcg) {

var c = hcg[1] / 100;
var g = hcg[2] / 100;

var v = c + g * (1.0 - c);
var f = 0;

if (v > 0.0) {
        f = c / v;
}

return [hcg[0], f * 100, v * 100];

};

convert.hcg.hsl = function (hcg) {

var c = hcg[1] / 100;
var g = hcg[2] / 100;

var l = g * (1.0 - c) + 0.5 * c;
var s = 0;

if (l > 0.0 && l < 0.5) {
        s = c / (2 * l);
} else
if (l >= 0.5 && l < 1.0) {
        s = c / (2 * (1 - l));
}

return [hcg[0], s * 100, l * 100];

};

convert.hcg.hwb = function (hcg) {

var c = hcg[1] / 100;
var g = hcg[2] / 100;
var v = c + g * (1.0 - c);
return [hcg[0], (v - c) * 100, (1 - v) * 100];

};

convert.hwb.hcg = function (hwb) {

var w = hwb[1] / 100;
var b = hwb[2] / 100;
var v = 1 - b;
var c = v - w;
var g = 0;

if (c < 1) {
        g = (v - c) / (1 - c);
}

return [hwb[0], c * 100, g * 100];

};

convert.apple.rgb = function (apple) {

return [(apple[0] / 65535) * 255, (apple[1] / 65535) * 255, (apple[2] / 65535) * 255];

};

convert.rgb.apple = function (rgb) {

return [(rgb[0] / 255) * 65535, (rgb[1] / 255) * 65535, (rgb[2] / 255) * 65535];

};

convert.gray.rgb = function (args) {

return [args[0] / 100 * 255, args[0] / 100 * 255, args[0] / 100 * 255];

};

convert.gray.hsl = convert.gray.hsv = function (args) {

return [0, 0, args[0]];

};

convert.gray.hwb = function (gray) {

return [0, 100, gray[0]];

};

convert.gray.cmyk = function (gray) {

return [0, 0, 0, gray[0]];

};

convert.gray.lab = function (gray) {

return [gray[0], 0, 0];

};

convert.gray.hex = function (gray) {

var val = Math.round(gray[0] / 100 * 255) & 0xFF;
var integer = (val << 16) + (val << 8) + val;

var string = integer.toString(16).toUpperCase();
return '000000'.substring(string.length) + string;

};

convert.rgb.gray = function (rgb) {

var val = (rgb[0] + rgb[1] + rgb[2]) / 3;
return [val / 255 * 100];

};