{-# LANGUAGE LinearTypes #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE NoImplicitPrelude #-}

module Test.Foreign (foreignGCTests) where

import Control.Exception hiding (assert)
import Control.Monad (void)
import Data.Typeable
import qualified Foreign.Heap as Heap
import Foreign.List (List)
import qualified Foreign.List as List
import qualified Foreign.Marshal.Pure as Manual
import Hedgehog
import qualified Hedgehog.Gen as Gen
import qualified Hedgehog.Range as Range
import Prelude.Linear
import Test.Tasty
import Test.Tasty.Hedgehog (testProperty)
import qualified Prelude

-- # Organizing tests
-------------------------------------------------------------------------------

foreignGCTests :: TestTree
foreignGCTests =
  testGroup
    "foreignGCTests"
    [ listExampleTests,
      heapExampleTests
    ]

listExampleTests :: TestTree
listExampleTests =
  testGroup
    "list tests"
    [ testProperty "List.toList . List.fromList = id" invertNonGCList,
      testProperty "map id = id" mapIdNonGCList,
      testProperty "memory freed post-exception" testExecptionOnMem
    ]

heapExampleTests :: TestTree
heapExampleTests =
  testGroup
    "heap tests"
    [testProperty "sort = heapsort" nonGCHeapSort]

-- # Internal library
-------------------------------------------------------------------------------

list :: Gen [Int]
list = Gen.list (Range.linear 0 1000) (Gen.int (Range.linear 0 100))

eqList ::
  forall a.
  (Manual.Representable a, Movable a, Eq a) =>
  List a %1 ->
  List a %1 ->
  Ur Bool
eqList l1 l2 = move $ (List.toList l1) == (List.toList l2)

data InjectedError = InjectedError
  deriving (Typeable, Show)

instance Exception InjectedError

-- # Properties
-------------------------------------------------------------------------------

invertNonGCList :: Property
invertNonGCList = property $ do
  xs <- forAll list
  let xs' =
        unur $
          Manual.withPool (\p -> move $ List.toList $ List.ofList xs p)
  xs === xs'

mapIdNonGCList :: Property
mapIdNonGCList = property $ do
  xs <- forAll list
  let boolTest = unur $
        Manual.withPool $ \p ->
          dup3 p & \(p0, p1, p2) ->
            eqList (List.ofList xs p0) (List.map id (List.ofList xs p1) p2)
  assert boolTest

testExecptionOnMem :: Property
testExecptionOnMem = property $ do
  xs <- forAll list
  let bs = xs ++ (throw InjectedError)
  let writeBadList = Manual.withPool (move . List.toList . List.ofRList bs)
  let ignoreCatch = \_ -> Prelude.return ()
  evalIO (catch @InjectedError (void (evaluate writeBadList)) ignoreCatch)

nonGCHeapSort :: Property
nonGCHeapSort = property $ do
  xs <- forAll list
  let ys :: [(Int, ())] = zip xs $ Prelude.replicate (Prelude.length xs) ()
  (Heap.sort ys) === (reverse $ sort ys)