import colorString from 'color-string';

function hue2rgb(p: number, q: number, m: number) {
  let t = m;
  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;
}

function hsl2rbg(hsl: number[]) {
  const h = hsl[0] / 360;
  const s = hsl[1] / 100;
  const l = hsl[2] / 100;
  const a = hsl[3];

  if (s === 0) return [l * 255, l * 255, l * 255, a];

  const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
  const p = 2 * l - q;
  const r = hue2rgb(p, q, h + 1 / 3);
  const g = hue2rgb(p, q, h);
  const b = hue2rgb(p, q, h - 1 / 3);
  return [r * 255, g * 255, b * 255, a];
}

export function string2rbg(s: string) {
  const color = colorString.get(s);
  if (!color) return null;
  const { model, value } = color;
  if (model === 'rgb') return value;
  if (model === 'hsl') return hsl2rbg(value);
  return null;
}