{-# LANGUAGE DataKinds           #-}
{-# LANGUAGE ScopedTypeVariables #-}

module Polysemy.ManagedSpec (spec) where

import Control.Concurrent.MVar (MVar)
import Control.Concurrent.MVar qualified as IO
import Control.Monad (forM_, void)
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.Resource qualified as MTR
import HaskellWorks.Hspec.Hedgehog qualified as H
import Hedgehog ((===), PropertyT)
import Polysemy (Final, Sem)
import Polysemy qualified as PY
import Polysemy.Embed (Embed)
import Polysemy.Managed qualified as PY
import Polysemy.Resource (Resource)
import Polysemy.Resource qualified as PY
import Test.Hspec (describe, it, Spec)

{- HLINT ignore "Redundant do" -}

runMainEffects :: forall a. ()
  => Sem '[Embed IO , Resource , Final IO] a
  -> IO a
runMainEffects =
    PY.runFinal
  . PY.resourceToIOFinal
  . PY.embedToFinal


run :: MVar [PropertyT IO ()] -> PropertyT IO () -> IO ()
run mv p = do
  ps <- IO.takeMVar mv
  IO.putMVar mv (p:ps)

spec :: Spec
spec = describe "Polysemy.ManagedSpec" $ do
  it "De-allocated allocated resource (embed)" $ H.requireTest $ do
    mva <- liftIO IO.newEmptyMVar
    result1 <- liftIO $ runMainEffects $
      PY.runManaged $ do
        void $ MTR.allocate (return ()) $ const (IO.putMVar mva ())
        liftIO $ IO.tryTakeMVar mva

    result2 <- liftIO $ IO.tryTakeMVar mva

    result1 === Nothing
    result2 === Just ()

  it "De-allocated allocated resource (final)" $ H.requireTest $ do
    mva <- liftIO IO.newEmptyMVar
    result1 <- liftIO $ runMainEffects $
      PY.runManagedFinal $ do
        void $ MTR.allocate (return ()) $ const (IO.putMVar mva ())
        liftIO $ IO.tryTakeMVar mva

    result2 <- liftIO $ IO.tryTakeMVar mva

    result1 === Nothing
    result2 === Just ()

  it "Has local capability (embed)" $ H.requireTest $ do
    mAssertions <- liftIO $ IO.newMVar []
    mva <- liftIO IO.newEmptyMVar
    mvb <- liftIO IO.newEmptyMVar
    liftIO $ runMainEffects $ do
      PY.runManaged $ do
        void $ MTR.allocate (return ()) $ const (IO.putMVar mva ())
        PY.managedLocal $ do
          liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Nothing
          liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Nothing
          void $ MTR.allocate (return ()) $ const $ IO.putMVar mvb ()
          liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Nothing
          liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Nothing
        liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Nothing
        liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Just ()
      liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Just ()
      liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Just ()

    liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Just ()
    liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Just ()

    assertions <- fmap reverse . liftIO $ IO.readMVar mAssertions

    forM_ assertions id

  it "Has local capability (final)" $ H.requireTest $ do
    mAssertions <- liftIO $ IO.newMVar []
    mva <- liftIO IO.newEmptyMVar
    mvb <- liftIO IO.newEmptyMVar
    liftIO $ runMainEffects $ do
      PY.runManagedFinal $ do
        void $ MTR.allocate (return ()) $ const (IO.putMVar mva ())
        PY.managedLocal $ do
          liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Nothing
          liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Nothing
          void $ MTR.allocate (return ()) $ const $ IO.putMVar mvb ()
          liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Nothing
          liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Nothing
        liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Nothing
        liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Just ()
      liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Just ()
      liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Just ()

    liftIO $ IO.tryReadMVar mva >>= \result -> run mAssertions $ result === Just ()
    liftIO $ IO.tryReadMVar mvb >>= \result -> run mAssertions $ result === Just ()

    assertions <- fmap reverse . liftIO $ IO.readMVar mAssertions

    forM_ assertions id