/**
 * Iquizeles color generator
 * @module lib/color.js;
 */

const palettes = [
  [
    [0.5, 0.5, 0.5],
    [0.5, 0.5, 0.5],
    [1.0, 1.0, 1.0],
    [0.0, 0.33, 0.67],
  ],
  [
    [0.5, 0.5, 0.5],
    [0.5, 0.5, 0.5],
    [1.0, 1.0, 1.0],
    [0.0, 0.1, 0.2],
  ],
  [
    [0.5, 0.5, 0.5],
    [0.5, 0.5, 0.5],
    [1.0, 1.0, 1.0],
    [0.3, 0.2, 0.2],
  ],
  [
    [0.5, 0.5, 0.5],
    [0.5, 0.5, 0.5],
    [1.0, 1.0, 0.5],
    [0.8, 0.9, 0.3],
  ],
  [
    [0.5, 0.5, 0.5],
    [0.5, 0.5, 0.5],
    [1.0, 0.7, 0.4],
    [0.0, 0.15, 0.2],
  ],
  [
    [0.5, 0.5, 0.5],
    [0.5, 0.5, 0.5],
    [2.0, 1.0, 0.0],
    [0.5, 0.2, 0.25],
  ],
  [
    [0.8, 0.5, 0.4],
    [0.2, 0.4, 0.2],
    [2.0, 1.0, 1.0],
    [0.0, 0.25, 0.25],
  ],
];

let palette = palettes[0];

function channel(t, a, b, c, d, add, mul) {
  return a + b * Math.cos(2 * Math.PI * (c * t + d)) * mul + add;
}

function color(t, add, mul) {
  let a, b, c, d;
  const rgb = [];
  for (var i = 0; i < 3; i++) {
    a = palette[0][i];
    b = palette[1][i];
    c = palette[2][i];
    d = palette[3][i];
    rgb[i] = Math.round(channel(t, a, b, c, d, add, mul) * 255);
  }
  return "rgb(" + rgb + ")";
}

export default color;