module Date
  ( Date(..)
  , getCurrentDate
  , sameDayAndMonth
  , isBeforeOrEqualDayAndMonth
  , isAfterOrEqualDayAndMonth
  , yearsGap
  ) where

import Data.Time.Clock
import Data.Time.Calendar
import Data.Time.LocalTime

data Date = Date
  { day :: Int
  , month :: Int
  , year :: Int
  } deriving (Eq, Show)

getCurrentDate :: IO Date
getCurrentDate = do
  now <- getCurrentTime
  timezone <- getCurrentTimeZone
  let zoneNow = utcToLocalTime timezone now
  let (y, m, d) = toGregorian $ localDay zoneNow
  return $ Date d m (fromIntegral y)

sameDayAndMonth :: Date -> Date -> Bool
sameDayAndMonth d1 d2 =
  (  day d1 == day d2
  && month d1 == month d2
  )

isBeforeOrEqualDayAndMonth :: Date -> Date -> Bool
isBeforeOrEqualDayAndMonth d1 d2 =
  (  month d1 < month d2
  || (  month d1 == month d2
     && day d1 <= day d2
     )
  )

isAfterOrEqualDayAndMonth :: Date -> Date -> Bool
isAfterOrEqualDayAndMonth d1 d2 =
  (  month d1 > month d2
  || (  month d1 == month d2
     && day d1 >= day d2
     )
  )

yearsGap :: Date -> Date -> Int
yearsGap d1 d2 = abs (year d2 - year d1)