colors.kt

fun main() {
  data class Colors(
    val color: Int,
    val complimentary: Int,
    val analogous: List<Int>,
    val tetradic: List<Int>
  ) {
    val colorNames = mapOf(
      0 to "yellow", 1 to "cad-yellow", 2 to "orange",
      3 to "cad-red", 4 to "red", 5 to "acra-violet",
      6 to "violet", 7 to "ultramarine-blue", 8 to "blue",
      9 to "pthalo-blue", 10 to "green", 11 to "hansa-yellow",
    )

    fun asColorNames(): String {
      return buildString {
        appendLine("color:" + colorNames[color])
        appendLine("complimentary: " + colorNames[complimentary])
        appendLine("analogous: " + analogous.map { colorNames[it] }.joinToString(","))
        appendLine("tetradic: " + tetradic.map { colorNames[it] }.joinToString(","))
      }
    }
  }

  fun List<Int>.wrapping(index: Int) = this[(if (index < 0) index + size else index) % size]

  val colorCodes = (0..11).toList()
  val randomColor = colorCodes.shuffled().first()
  println(
    Colors(
      color = randomColor,
      complimentary = colorCodes.wrapping(randomColor + 6),
      analogous = listOf(
        colorCodes.wrapping(randomColor - 1),
        randomColor,
        colorCodes.wrapping(randomColor + 1),
      ),
      tetradic = listOf(
        colorCodes.wrapping(randomColor + 2),
        colorCodes.wrapping(randomColor + 4),
        colorCodes.wrapping(randomColor + 8),
        colorCodes.wrapping(randomColor + 10),
      )
    ).asColorNames()
  )
}

color:green
complimentary: red
analogous: pthalo-blue,green,hansa-yellow
tetradic: yellow,orange,violet,blue