/* eslint-disable prefer-const */

import { GumRgbToHsl } from '../models';

/**
 * Converts RGB color value to HSL
 * @param r Red
 * @param g Green
 * @param b Blue
 */
export const rgbToHsl: GumRgbToHsl = (r, g, b) => {
  let d, h, l, max, min, s;
  r /= 255;
  g /= 255;
  b /= 255;
  max = Math.max(r, g, b);
  min = Math.min(r, g, b);
  h = 0;
  s = 0;
  l = (max + min) / 2;
  if (max === min) {
    h = s = 0;
  } else {
    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;
    }
    h /= 6;
  }
  h = Math.round(h * 360 * 100) / 100;
  s = Math.round(s * 100 * 100) / 100;
  l = Math.round(l * 100 * 100) / 100;
  return [h, s, l] as [number, number, number];
};