commerce/lib/colors.ts

import { random } from 'lodash'

export function getRandomPairOfColors() {
  const colors = ['#37B679', '#DA3C3C', '#3291FF', '#7928CA', '#79FFE1']
  const getRandomIdx = () => random(0, colors.length - 1)
  let idx = getRandomIdx()
  let idx2 = getRandomIdx()

  // Has to be a different color
  while (idx2 === idx) {
    idx2 = getRandomIdx()
  }

  // Returns a pair of colors
  return [colors[idx], colors[idx2]]
}

function hexToRgb(hex: string = '') {
  const match = hex.toString(16).match(/[a-f0-9]{6}|[a-f0-9]{3}/i)

  if (!match) {
    return [0, 0, 0]
  }

  let colorString = match[0]

  if (match[0].length === 3) {
    colorString = colorString
      .split('')
      .map((char: string) => {
        return char + char
      })
      .join('')
  }

  const integer = parseInt(colorString, 16)
  const r = (integer >> 16) & 0xff
  const g = (integer >> 8) & 0xff
  const b = integer & 0xff

  return [r, g, b]
}

export function isDark(color = '') {
  // Equation from http://24ways.org/2010/calculating-color-contrast
  const rgb = hexToRgb(color)
  const res = (rgb[0] * 299 + rgb[1] * 587 + rgb[2] * 114) / 1000
  return res < 128
}