module System.Test.Cron.Internal.Schedule
  ( tests,
  )
where

-------------------------------------------------------------------------------
import Hedgehog
-------------------------------------------------------------------------------
import SpecHelper
import System.Cron.Internal.Schedule

-------------------------------------------------------------------------------

tests :: TestTree
tests =
  testGroup
    "System.Cron.Schedule"
    [ describeFindNextMinuteDelay'
    ]

describeFindNextMinuteDelay' :: TestTree
describeFindNextMinuteDelay' =
  testGroup
    "findNextMinuteDelay'"
    [ testCase "should find next minute of arbitrary time." $
        let now = UTCTime {utctDay = ModifiedJulianDay 58906, utctDayTime = picosecondsToDiffTime 29085749437046123} -- 2020-02-27 08:04:45.749437046 UTC
            nextMinute = UTCTime {utctDay = ModifiedJulianDay 58906, utctDayTime = picosecondsToDiffTime 29100000000000000} -- 2020-02-27 08:05:00.000000000 UTC
         in findNextMinuteDelay' now @?= (nextMinute, 14250563),
      testCase "should find next minute of 59 minutes." $
        let now = UTCTime {utctDay = ModifiedJulianDay 58906, utctDayTime = picosecondsToDiffTime 32357749437046123} -- 2020-02-27 08:59:17.749437046123 UTC
            nextMinute = UTCTime {utctDay = ModifiedJulianDay 58906, utctDayTime = picosecondsToDiffTime 32400000000000000} -- 2020-02-27 09:00:00.000000000 UTC
         in findNextMinuteDelay' now @?= (nextMinute, 42250563),
      testCase "should find next minute of 0 minute." $
        let now = UTCTime {utctDay = ModifiedJulianDay 58906, utctDayTime = picosecondsToDiffTime 32400123456789012} -- 2020-02-27 09:00:00.123456789012 UTC
            nextMinute = UTCTime {utctDay = ModifiedJulianDay 58906, utctDayTime = picosecondsToDiffTime 32460000000000000} -- 2020-02-27 09:01:00.000000000 UTC
         in findNextMinuteDelay' now @?= (nextMinute, 59876543),
      testCase "should find next minute before midnight." $
        let now = UTCTime {utctDay = ModifiedJulianDay 58906, utctDayTime = picosecondsToDiffTime 86387123456789012} -- 2020-02-27 23:59:47.123456789012 UTC
            nextMinute = UTCTime {utctDay = ModifiedJulianDay 58907, utctDayTime = picosecondsToDiffTime 0} -- 2020-02-28 00:00:00.000000000 UTC
         in findNextMinuteDelay' now @?= (nextMinute, 12876543),
      testProperty "invariance: next minute is after and no more than 60s later." $ property $ do
        now <- forAll gen
        let (nextMinute, delay) = findNextMinuteDelay' now
        ((nextMinute > now) && (delay <= 60000000)) === True,
      testProperty "invariance: next minute after next minute is *exactly* 60s." $ property $ do
        now <- forAll gen
        let (nextMinute1, _) = findNextMinuteDelay' now
        let (nextMinute2, delay) = findNextMinuteDelay' nextMinute1
        ((diffUTCTime nextMinute2 nextMinute1 == 60) && (delay == 60000000)) === True
    ]