module SpaceAge (Planet(..), ageOn) where

data Planet = Mercury
            | Venus
            | Earth
            | Mars
            | Jupiter
            | Saturn
            | Uranus
            | Neptune

ageOn :: Planet -> Float -> Float
ageOn planet seconds = seconds / (earthPeriod * planetMultiplier)
  where
    planetMultiplier = case planet of
      Mercury -> 0.2408467
      Venus   -> 0.61519726
      Earth   -> 1
      Mars    -> 1.8808158
      Jupiter -> 11.862615
      Saturn  -> 29.447498
      Uranus  -> 84.016846
      Neptune -> 164.79132
    earthPeriod = 31557600