module Gamgee.Effects.CryptoRandom
    ( -- * Effect
      CryptoRandom(..)

      -- * Action
    , randomBytes

      -- * Interpretations
    , runCryptoRandomIO
    ) where

import qualified Crypto.Random.Types as CRT
import qualified Data.ByteArray      as BA
import           Polysemy            (Lift, Member, Sem)
import qualified Polysemy            as P
import           Relude


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-- Effects
----------------------------------------------------------------------------------------------------

-- | An effect capable of providing random bytes for use with cryptonite
data CryptoRandom m a where
  -- | Generate random bytes
  RandomBytes :: BA.ByteArray b => Int -> CryptoRandom m b

P.makeSem ''CryptoRandom


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-- Interpretations
----------------------------------------------------------------------------------------------------

runCryptoRandomIO :: Member (Lift IO) r => Sem (CryptoRandom : r) a -> Sem r a
runCryptoRandomIO = P.interpret $ \case
  RandomBytes count -> P.sendM @IO $ CRT.getRandomBytes count