{-# LANGUAGE CPP #-}
module Test.Hspec.Core.QuickCheckUtil where

import           Control.Applicative
import           Data.Int
import           Data.IORef
import           Test.QuickCheck hiding (Result(..))
import           Test.QuickCheck as QC
import           Test.QuickCheck.Property hiding (Result(..))
import           Test.QuickCheck.Gen
import qualified Test.QuickCheck.Property as QCP
import           Test.QuickCheck.IO ()


#if MIN_VERSION_QuickCheck(2,7,0)
import           Test.QuickCheck.Random
#endif

import           System.Random

import           Test.Hspec.Core.Util

aroundProperty :: ((a -> IO ()) -> IO ()) -> (a -> Property) -> Property
#if MIN_VERSION_QuickCheck(2,7,0)
aroundProperty action p = MkProperty . MkGen $ \r n -> aroundProp action $ \a -> (unGen . unProperty $ p a) r n
#else
aroundProperty action p = MkGen $ \r n -> aroundProp action $ \a -> (unGen $ p a) r n
#endif

aroundProp :: ((a -> IO ()) -> IO ()) -> (a -> Prop) -> Prop
aroundProp action p = MkProp $ aroundRose action (\a -> unProp $ p a)

aroundRose :: ((a -> IO ()) -> IO ()) -> (a -> Rose QCP.Result) -> Rose QCP.Result
aroundRose action r = ioRose $ do
  ref <- newIORef (return QCP.succeeded)
  action $ \a -> reduceRose (r a) >>= writeIORef ref
  readIORef ref

formatNumbers :: Result -> String
formatNumbers r = "(after " ++ pluralize (numTests r) "test" ++ shrinks ++ ")"
  where
    shrinks
      | 0 < numShrinks r = " and " ++ pluralize (numShrinks r) "shrink"
      | otherwise = ""

newSeed :: IO Int
newSeed = fst . randomR (0, fromIntegral (maxBound :: Int32)) <$>
#if MIN_VERSION_QuickCheck(2,7,0)
  newQCGen
#else
  newStdGen
#endif

#if MIN_VERSION_QuickCheck(2,7,0)
mkGen :: Int -> QCGen
mkGen = mkQCGen
#else
mkGen :: Int -> StdGen
mkGen = mkStdGen
#endif