culori/src/hsl/parseHslLegacy.js

A general-purpose color library for JavaScript

import hueToDeg from '../util/hue.js';
import { hue, per, num_per, c } from '../util/regex.js';

/*
	hsl() regular expressions for legacy format
	Reference: https://drafts.csswg.org/css-color/#the-hsl-notation
 */
const hsl_old = new RegExp(
	`^hsla?\\(\\s*${hue}${c}${per}${c}${per}\\s*(?:,\\s*${num_per}\\s*)?\\)$`
);

const parseHslLegacy = color => {
	let match = color.match(hsl_old);
	if (!match) return;
	let res = { mode: 'hsl' };

	if (match[3] !== undefined) {
		res.h = +match[3];
	} else if (match[1] !== undefined && match[2] !== undefined) {
		res.h = hueToDeg(match[1], match[2]);
	}

	if (match[4] !== undefined) {
		res.s = Math.min(Math.max(0, match[4] / 100), 1);
	}

	if (match[5] !== undefined) {
		res.l = Math.min(Math.max(0, match[5] / 100), 1);
	}

	if (match[6] !== undefined) {
		res.alpha = Math.max(0, Math.min(1, match[6] / 100));
	} else if (match[7] !== undefined) {
		res.alpha = Math.max(0, Math.min(1, +match[7]));
	}
	return res;
};

export default parseHslLegacy;