module Golden where

import Control.Monad (Monad(..))
import Data.Function (($), (.))
import Data.Functor ((<$>))
import Data.Semigroup (Semigroup(..))
import Data.String (String)
-- import System.FilePath (FilePath)
import System.IO (IO)
import qualified Data.ByteString.Lazy as BSL
import qualified Data.List as List
import qualified Data.Text.Lazy          as TL
import qualified Data.Text.Lazy.Encoding as TL

import Test.Tasty
import Test.Tasty.Golden

import Language.Symantic.Grammar
import Language.Symantic
import Language.Symantic.Lib ()

-- * Golden testing utilities
testGolden :: TestName -> TestName -> IO BSL.ByteString -> TestTree
testGolden inputFile expectedExt =
	goldenVsStringDiff inputFile diffGolden (inputFile <> expectedExt)

diffGolden :: FilePath -> FilePath -> [String]
diffGolden ref new = ["diff", "-u", ref, new]

-- * All golden tests
goldensIO :: IO TestTree
goldensIO = do
	-- inputFiles <- List.sort <$> findByExtension [".sym"] "test/Golden"
	return $
		testGroup "Golden"
		 [ testGolden "grammar.ebnf" "" $ do
			return $
				TL.encodeUtf8 $
				TL.unlines $
				List.concat
				 [ render <$> gram_comment
				 , render <$> gram_type
				 , render <$> gram_term
				 ]
		 ]
	where render = TL.fromStrict . renderEBNF . unCF