/**
 * @module color-space/hsl
 */
'use strict'

var rgb = require('./rgb');

module.exports = {
	name: 'hsl',
	min: [0,0,0],
	max: [360,100,100],
	channel: ['hue', 'saturation', 'lightness'],
	alias: ['HSL'],

	rgb: function(hsl) {
		var h = hsl[0] / 360,
				s = hsl[1] / 100,
				l = hsl[2] / 100,
				t1, t2, t3, rgb, 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++;
			}
			else 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;
	}
};


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