module.exports = function LAB(color) {
    color.use(require('./XYZ.js'));

    color.installColorSpace('LAB', ['l', 'a', 'b', 'alpha'], {
        fromRgb: function () {
            return this.xyz().lab();
        },

        rgb: function () {
            return this.xyz().rgb();
        },

        xyz: function () {
            // http://www.easyrgb.com/index.php?X=MATH&H=08#text8
            var convert = function (channel) {
                    var pow = Math.pow(channel, 3);
                    return pow > 0.008856 ?
                        pow :
                        (channel - 16 / 116) / 7.87;
                },
                y = (this._l + 16) / 116,
                x = this._a / 500 + y,
                z = y - this._b / 200;

            return new color.XYZ(
                convert(x) *  95.047,
                convert(y) * 100.000,
                convert(z) * 108.883,
                this._alpha
            );
        }
    });
};