lowdefy/lowdefy

/* eslint-disable no-param-reassign */
/*
  Copyright 2020-2024 Lowdefy, Inc

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/

// antd v4.5.6
// https://github.com/ant-design/ant-design/blob/master/components/style/color/tinyColor.less
// 2020-09-23, MIT License
// TinyColor v1.4.1
// https://github.com/bgrins/TinyColor
// 2016-07-07, Brian Grinstead, MIT License

import tinycolor from 'tinycolor2';

const hueStep = 2;
const saturationStep = 0.16;
const saturationStep2 = 0.05;
const brightnessStep1 = 0.05;
const brightnessStep2 = 0.15;
const lightColorCount = 5;
const darkColorCount = 4;

const getHue = (hsv, i, isLight) => {
  let hue;
  if (hsv.h >= 60 && hsv.h <= 240) {
    hue = isLight ? hsv.h - hueStep * i : hsv.h + hueStep * i;
  } else {
    hue = isLight ? hsv.h + hueStep * i : hsv.h - hueStep * i;
  }
  if (hue < 0) {
    hue += 360;
  } else if (hue >= 360) {
    hue -= 360;
  }
  return Math.round(hue);
};

const getSaturation = (hsv, i, isLight) => {
  let saturation;
  if (isLight) {
    saturation = hsv.s - saturationStep * i;
  } else if (i === darkColorCount) {
    saturation = hsv.s + saturationStep;
  } else {
    saturation = hsv.s + saturationStep2 * i;
  }
  if (saturation > 1) {
    saturation = 1;
  }
  if (isLight && i === lightColorCount && saturation > 0.1) {
    saturation = 0.1;
  }
  if (saturation < 0.06) {
    saturation = 0.06;
  }
  return Number(saturation.toFixed(2));
};

const getValue = (hsv, i, isLight) => {
  let value;
  if (isLight) {
    value = hsv.v + brightnessStep1 * i;
  } else {
    value = hsv.v - brightnessStep2 * i;
  }
  if (value > 1) {
    value = 1;
  }
  return Number(value.toFixed(2));
};

const colorPalette = (color, index) => {
  const isLight = index <= 6;
  const hsv = tinycolor(color).toHsv();
  const i = isLight ? lightColorCount + 1 - index : index - lightColorCount - 1;
  return tinycolor({
    h: getHue(hsv, i, isLight),
    s: getSaturation(hsv, i, isLight),
    v: getValue(hsv, i, isLight),
  }).toHexString();
};

export default colorPalette;