module Minilang.IOSpec where

import Control.Exception (bracket)
import Minilang.IO (runEval)
import System.Directory (getTemporaryDirectory, removeFile)
import System.FilePath ((<.>), (</>))
import System.IO (IOMode (..), hClose, readFile, withFile, writeFile)
import System.Posix (mkstemp)
import Test.Hspec (Spec, around, describe, it, parallel, shouldBe)
import Prelude hiding (lines, readFile, writeFile)

spec :: Spec
spec = parallel $
  describe "MiniLang I/O Evaluator" $ do
    around withTempFile $
      it "evaluates a simple MiniLang 'program' and dumps result" $ \fileName -> do
        let outputFileName = fileName <> ".out"
            program =
              [ "((lam (x y) x) z t)"
              ]

        writeFile fileName (unlines program)

        _ <- withFile fileName ReadMode $ \hin ->
          withFile outputFileName AppendMode $ \hout ->
            runEval hin hout

        out <- readFile outputFileName

        out `shouldBe` "Var \"z\"\n"

withTempFile :: (String -> IO ()) -> IO ()
withTempFile =
  bracket mkTempFile rmTempFile
  where
    mkTempFile = getTemporaryDirectory >>= \dir -> mkstemp (dir </> "test-repl") >>= \(fp, h) -> hClose h >> pure fp
    rmTempFile fn = removeFile fn >> removeFile (fn <.> "out")