color converter: rgb 2 HSL, hex 2 rgb

ColorConverter.js

class ColorConverter {
    // Hex to RGB
    static hexToRgb(hex) {
        let cleanHex = hex.replace('#', '');
        if (cleanHex.length === 3) {
            cleanHex = cleanHex.split('').map(char => char + char).join('');
        }
        const bigint = parseInt(cleanHex, 16);
        const r = (bigint >> 16) & 255;
        const g = (bigint >> 8) & 255;
        const b = bigint & 255;
        return `rgb(${r}, ${g}, ${b})`;
    }

    // Hex to RGBA
    static hexToRgba(hex, alpha = 1) {
        const rgb = this.hexToRgb(hex);
        return rgb.replace('rgb', 'rgba').replace(')', `, ${alpha})`);
    }

    // RGB to Hex
    static rgbToHex(r, g, b) {
        const toHex = (val) => val.toString(16).padStart(2, '0');
        return `#${toHex(r)}${toHex(g)}${toHex(b)}`;
    }

    // RGBA to Hex
    static rgbaToHex(r, g, b, a = 1) {
        const alpha = Math.round(a * 255);
        return this.rgbToHex(r, g, b) + alpha.toString(16).padStart(2, '0');
    }

    // ARGB to Hex
    static argbToHex(a, r, g, b) {
        const toHex = (val) => val.toString(16).padStart(2, '0');
        return `#${toHex(a)}${toHex(r)}${toHex(g)}${toHex(b)}`;
    }

    // RGB to HSL
    static rgbToHsl(r, g, b) {
        r /= 255;
        g /= 255;
        b /= 255;
        const max = Math.max(r, g, b), min = Math.min(r, g, b);
        let h, s, l = (max + min) / 2;

        if (max === min) {
            h = s = 0;
        } else {
            const 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 `hsl(${(h * 360).toFixed(1)}, ${(s * 100).toFixed(1)}%, ${(l * 100).toFixed(1)}%)`;
    }

    // HSL to RGB
    static hslToRgb(h, s, l) {
        s /= 100;
        l /= 100;
        h /= 360;

        let r, g, b;

        if (s === 0) {
            r = g = b = l;
        } else {
            const 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 / 3) return q;
                if (t < 1 / 2) return p + (q - p) * (2 / 3 - t) * 6;
                return p;
            };

            const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
            const p = 2 * l - q;

            r = hue2rgb(p, q, h + 1 / 3);
            g = hue2rgb(p, q, h);
            b = hue2rgb(p, q, h - 1 / 3);
        }

        return `rgb(${Math.round(r * 255)}, ${Math.round(g * 255)}, ${Math.round(b * 255)})`;
    }

    // HSL to HSLA
    static hslToHsla(h, s, l, a = 1) {
        return `hsla(${h}, ${s}%, ${l}%, ${a})`;
    }

    // RGB to HSLA
    static rgbToHsla(r, g, b, a = 1) {
        const hsl = this.rgbToHsl(r, g, b).replace('hsl', '');
        return `hsla${hsl.slice(0, -1)}, ${a})`;
    }

    // RGB to ARGB (alpha first)
    static rgbToArgb(r, g, b, a = 1) {
        const alpha = Math.round(a * 255);
        return this.argbToHex(alpha, r, g, b);
    }
}