/**
 * @namespace Color operations
 */
ROT.Color = {
	fromString: function(str) {
		var cached, r;
		if (str in this._cache) {
			cached = this._cache[str];
		} else {
			if (str.charAt(0) == "#") { /* hex rgb */

				var values = str.match(/[0-9a-f]/gi).map(function(x) { return parseInt(x, 16); });
				if (values.length == 3) {
					cached = values.map(function(x) { return x*17; });
				} else {
					for (var i=0;i<3;i++) {
						values[i+1] += 16*values[i];
						values.splice(i, 1);
					}
					cached = values;
				}

			} else if (r = str.match(/rgb\(([0-9, ]+)\)/i)) { /* decimal rgb */
				cached = r[1].split(/\s*,\s*/).map(function(x) { return parseInt(x); });
			} else { /* html name */
				cached = [0, 0, 0];
			}

			this._cache[str] = cached;
		}

		return cached.slice();
	},

	/**
	 * Add two or more colors
	 * @param {number[]} color1
	 * @param {number[]} color2
	 * @returns {number[]}
	 */
	add: function(color1, color2) {
		var result = color1.slice();
		for (var i=0;i<3;i++) {
			for (var j=1;j<arguments.length;j++) {
				result[i] += arguments[j][i];
			}
		}
		return result;
	},

	/**
	 * Add two or more colors, MODIFIES FIRST ARGUMENT
	 * @param {number[]} color1
	 * @param {number[]} color2
	 * @returns {number[]}
	 */
	add_: function(color1, color2) {
		for (var i=0;i<3;i++) {
			for (var j=1;j<arguments.length;j++) {
				color1[i] += arguments[j][i];
			}
		}
		return color1;
	},

	/**
	 * Multiply (mix) two or more colors
	 * @param {number[]} color1
	 * @param {number[]} color2
	 * @returns {number[]}
	 */
	multiply: function(color1, color2) {
		var result = color1.slice();
		for (var i=0;i<3;i++) {
			for (var j=1;j<arguments.length;j++) {
				result[i] *= arguments[j][i] / 255;
			}
			result[i] = Math.round(result[i]);
		}
		return result;
	},

	/**
	 * Multiply (mix) two or more colors, MODIFIES FIRST ARGUMENT
	 * @param {number[]} color1
	 * @param {number[]} color2
	 * @returns {number[]}
	 */
	multiply_: function(color1, color2) {
		for (var i=0;i<3;i++) {
			for (var j=1;j<arguments.length;j++) {
				color1[i] *= arguments[j][i] / 255;
			}
			color1[i] = Math.round(color1[i]);
		}
		return color1;
	},

	/**
	 * Interpolate (blend) two colors with a given factor
	 * @param {number[]} color1
	 * @param {number[]} color2
	 * @param {float} [factor=0.5] 0..1
	 * @returns {number[]}
	 */
	interpolate: function(color1, color2, factor) {
		if (arguments.length < 3) { factor = 0.5; }
		var result = color1.slice();
		for (var i=0;i<3;i++) {
			result[i] = Math.round(result[i] + factor*(color2[i]-color1[i]));
		}
		return result;
	},

	/**
	 * Interpolate (blend) two colors with a given factor in HSL mode
	 * @param {number[]} color1
	 * @param {number[]} color2
	 * @param {float} [factor=0.5] 0..1
	 * @returns {number[]}
	 */
	interpolateHSL: function(color1, color2, factor) {
		if (arguments.length < 3) { factor = 0.5; }
		var hsl1 = this.rgb2hsl(color1);
		var hsl2 = this.rgb2hsl(color2);
		for (var i=0;i<3;i++) {
			hsl1[i] += factor*(hsl2[i]-hsl1[i]);
		}
		return this.hsl2rgb(hsl1);
	},

	/**
	 * Create a new random color based on this one
	 * @param {number[]} color
	 * @param {number[]} diff Set of standard deviations
	 * @returns {number[]}
	 */
	randomize: function(color, diff) {
		if (!(diff instanceof Array)) { diff = ROT.RNG.getNormal(0, diff); }
		var result = color.slice();
		for (var i=0;i<3;i++) {
			result[i] += (diff instanceof Array ? Math.round(ROT.RNG.getNormal(0, diff[i])) : diff);
		}
		return result;
	},

	/**
	 * Converts an RGB color value to HSL. Expects 0..255 inputs, produces 0..1 outputs.
	 * @param {number[]} color
	 * @returns {number[]}
	 */
	rgb2hsl: function(color) {
		var r = color[0]/255;
		var g = color[1]/255;
		var b = color[2]/255;

		var max = Math.max(r, g, b), min = Math.min(r, g, b);
		var h, s, l = (max + min) / 2;

		if (max == min) {
			h = s = 0; // achromatic
		} else {
			var d = max - min;
			s = (l > 0.5 ? d / (2 - max - min) : d / (max + min));
			switch(max) {
				case r: h = (g - b) / d + (g < b ? 6 : 0); break;
				case g: h = (b - r) / d + 2; break;
				case b: h = (r - g) / d + 4; break;
			}
			h /= 6;
		}

		return [h, s, l];
	},

	/**
	 * Converts an HSL color value to RGB. Expects 0..1 inputs, produces 0..255 outputs.
	 * @param {number[]} color
	 * @returns {number[]}
	 */
	hsl2rgb: function(color) {
		var l = color[2];

		if (color[1] == 0) {
			l *= 255;
			return [l, l, l];
		} else {
			function hue2rgb(p, q, t) {
				if (t < 0) t += 1;
				if (t > 1) t -= 1;
				if (t < 1/6) return p + (q - p) * 6 * t;
				if (t < 1/2) return q;
				if (t < 2/3) return p + (q - p) * (2/3 - t) * 6;
				return p;
			}

			var s = color[1];
			var q = (l < 0.5 ? l * (1 + s) : l + s - l * s);
			var p = 2 * l - q;
			var r = hue2rgb(p, q, color[0] + 1/3);
			var g = hue2rgb(p, q, color[0]);
			var b = hue2rgb(p, q, color[0] - 1/3);
			return [Math.round(r*255), Math.round(g*255), Math.round(b*255)];
		}
	},

	toRGB: function(color) {
		return "rgb(" + this._clamp(color[0]) + "," + this._clamp(color[1]) + "," + this._clamp(color[2]) + ")";
	},

	toHex: function(color) {
		var parts = [];
		for (var i=0;i<3;i++) {
			parts.push(this._clamp(color[i]).toString(16).lpad("0", 2));
		}
		return "#" + parts.join("");
	},

	_clamp: function(num) {
		if (num < 0) {
			return 0;
		} else if (num > 255) {
			return 255;
		} else {
			return num;
		}
	},

	_cache: {
		"black": [0,0,0],
		"navy": [0,0,128],
		"darkblue": [0,0,139],
		"mediumblue": [0,0,205],
		"blue": [0,0,255],
		"darkgreen": [0,100,0],
		"green": [0,128,0],
		"teal": [0,128,128],
		"darkcyan": [0,139,139],
		"deepskyblue": [0,191,255],
		"darkturquoise": [0,206,209],
		"mediumspringgreen": [0,250,154],
		"lime": [0,255,0],
		"springgreen": [0,255,127],
		"aqua": [0,255,255],
		"cyan": [0,255,255],
		"midnightblue": [25,25,112],
		"dodgerblue": [30,144,255],
		"forestgreen": [34,139,34],
		"seagreen": [46,139,87],
		"darkslategray": [47,79,79],
		"darkslategrey": [47,79,79],
		"limegreen": [50,205,50],
		"mediumseagreen": [60,179,113],
		"turquoise": [64,224,208],
		"royalblue": [65,105,225],
		"steelblue": [70,130,180],
		"darkslateblue": [72,61,139],
		"mediumturquoise": [72,209,204],
		"indigo": [75,0,130],
		"darkolivegreen": [85,107,47],
		"cadetblue": [95,158,160],
		"cornflowerblue": [100,149,237],
		"mediumaquamarine": [102,205,170],
		"dimgray": [105,105,105],
		"dimgrey": [105,105,105],
		"slateblue": [106,90,205],
		"olivedrab": [107,142,35],
		"slategray": [112,128,144],
		"slategrey": [112,128,144],
		"lightslategray": [119,136,153],
		"lightslategrey": [119,136,153],
		"mediumslateblue": [123,104,238],
		"lawngreen": [124,252,0],
		"chartreuse": [127,255,0],
		"aquamarine": [127,255,212],
		"maroon": [128,0,0],
		"purple": [128,0,128],
		"olive": [128,128,0],
		"gray": [128,128,128],
		"grey": [128,128,128],
		"skyblue": [135,206,235],
		"lightskyblue": [135,206,250],
		"blueviolet": [138,43,226],
		"darkred": [139,0,0],
		"darkmagenta": [139,0,139],
		"saddlebrown": [139,69,19],
		"darkseagreen": [143,188,143],
		"lightgreen": [144,238,144],
		"mediumpurple": [147,112,216],
		"darkviolet": [148,0,211],
		"palegreen": [152,251,152],
		"darkorchid": [153,50,204],
		"yellowgreen": [154,205,50],
		"sienna": [160,82,45],
		"brown": [165,42,42],
		"darkgray": [169,169,169],
		"darkgrey": [169,169,169],
		"lightblue": [173,216,230],
		"greenyellow": [173,255,47],
		"paleturquoise": [175,238,238],
		"lightsteelblue": [176,196,222],
		"powderblue": [176,224,230],
		"firebrick": [178,34,34],
		"darkgoldenrod": [184,134,11],
		"mediumorchid": [186,85,211],
		"rosybrown": [188,143,143],
		"darkkhaki": [189,183,107],
		"silver": [192,192,192],
		"mediumvioletred": [199,21,133],
		"indianred": [205,92,92],
		"peru": [205,133,63],
		"chocolate": [210,105,30],
		"tan": [210,180,140],
		"lightgray": [211,211,211],
		"lightgrey": [211,211,211],
		"palevioletred": [216,112,147],
		"thistle": [216,191,216],
		"orchid": [218,112,214],
		"goldenrod": [218,165,32],
		"crimson": [220,20,60],
		"gainsboro": [220,220,220],
		"plum": [221,160,221],
		"burlywood": [222,184,135],
		"lightcyan": [224,255,255],
		"lavender": [230,230,250],
		"darksalmon": [233,150,122],
		"violet": [238,130,238],
		"palegoldenrod": [238,232,170],
		"lightcoral": [240,128,128],
		"khaki": [240,230,140],
		"aliceblue": [240,248,255],
		"honeydew": [240,255,240],
		"azure": [240,255,255],
		"sandybrown": [244,164,96],
		"wheat": [245,222,179],
		"beige": [245,245,220],
		"whitesmoke": [245,245,245],
		"mintcream": [245,255,250],
		"ghostwhite": [248,248,255],
		"salmon": [250,128,114],
		"antiquewhite": [250,235,215],
		"linen": [250,240,230],
		"lightgoldenrodyellow": [250,250,210],
		"oldlace": [253,245,230],
		"red": [255,0,0],
		"fuchsia": [255,0,255],
		"magenta": [255,0,255],
		"deeppink": [255,20,147],
		"orangered": [255,69,0],
		"tomato": [255,99,71],
		"hotpink": [255,105,180],
		"coral": [255,127,80],
		"darkorange": [255,140,0],
		"lightsalmon": [255,160,122],
		"orange": [255,165,0],
		"lightpink": [255,182,193],
		"pink": [255,192,203],
		"gold": [255,215,0],
		"peachpuff": [255,218,185],
		"navajowhite": [255,222,173],
		"moccasin": [255,228,181],
		"bisque": [255,228,196],
		"mistyrose": [255,228,225],
		"blanchedalmond": [255,235,205],
		"papayawhip": [255,239,213],
		"lavenderblush": [255,240,245],
		"seashell": [255,245,238],
		"cornsilk": [255,248,220],
		"lemonchiffon": [255,250,205],
		"floralwhite": [255,250,240],
		"snow": [255,250,250],
		"yellow": [255,255,0],
		"lightyellow": [255,255,224],
		"ivory": [255,255,240],
		"white": [255,255,255]
	}
}