shrub/pkg/king/lib/Vere/Behn.hs
2019-08-28 17:26:59 -07:00

45 lines
1.1 KiB
Haskell

module Vere.Behn (behn) where
import UrbitPrelude
import Arvo hiding (Behn)
import Vere.Pier.Types
import Urbit.Time (Wen)
import Urbit.Timer (Timer)
import qualified Urbit.Time as Time
import qualified Urbit.Timer as Timer
-- Behn Stuff ------------------------------------------------------------------
bornEv :: KingId -> Ev
bornEv king = EvBlip $ BlipEvBehn $ BehnEvBorn (king, ()) ()
wakeEv :: Ev
wakeEv = EvBlip $ BlipEvBehn $ BehnEvWake () ()
sysTime = view Time.systemTime
behn :: KingId -> QueueEv -> ([Ev], Acquire (EffCb e BehnEf))
behn king enqueueEv =
(initialEvents, runBehn)
where
initialEvents = [bornEv king]
runBehn :: Acquire (EffCb e BehnEf)
runBehn = do
tim <- mkAcquire Timer.init Timer.stop
pure (handleEf tim)
handleEf :: Timer -> BehnEf -> RIO e ()
handleEf b = io . \case
BehnEfVoid v -> absurd v
BehnEfDoze (i, ()) mWen -> do
when (i == king) (doze b mWen)
doze :: Timer -> Maybe Wen -> IO ()
doze tim = \case
Nothing -> Timer.stop tim
Just t -> Timer.start tim (sysTime t) $ atomically (enqueueEv wakeEv)