/* eslint-disable no-restricted-globals */

/**
 * Convert RGB values to CMYK
 * @param R {number}
 * @param G {number}
 * @param B {number}
 * @return { C: string, M: string, Y: string, K: string }
 * @example RGBToCMYK(255, 255, 255)
 */
const RGBToCMYK = (R: number, G: number, B: number): { C: number; M: number; Y: number; K: number } | undefined => {
  let c
  let m
  let y
  let k

  const r = parseInt(`${R}`.replace(/\s/g, ``), 10)
  const g = parseInt(`${G}`.replace(/\s/g, ``), 10)
  const b = parseInt(`${B}`.replace(/\s/g, ``), 10)

  if (r == null || g == null || b == null || isNaN(r) || isNaN(g) || isNaN(b)) {
    console.warn(`Please enter numeric RGB values!`)
    return
  }
  if (r < 0 || g < 0 || b < 0 || r > 255 || g > 255 || b > 255) {
    console.warn(`RGB values must be in the range 0 to 255.`)
    return
  }

  if (r === 0 && g === 0 && b === 0) {
    return {
      C: 0,
      M: 0,
      Y: 0,
      K: 100,
    }
  }

  c = 1 - r / 255
  m = 1 - g / 255
  y = 1 - b / 255

  const minCMY = Math.min(c, Math.min(m, y))
  c = (c - minCMY) / (1 - minCMY)
  m = (m - minCMY) / (1 - minCMY)
  y = (y - minCMY) / (1 - minCMY)
  k = minCMY

  c = Math.round(c * 100)
  m = Math.round(m * 100)
  y = Math.round(y * 100)
  k = Math.round(k * 100)

  return {
    C: c,
    M: m,
    Y: y,
    K: k,
  }
}

export default RGBToCMYK