# Pastebin jb5JxydO
import           Data.ByteString.Lazy       (ByteString)
import qualified Data.ByteString.Lazy.Char8 as BC
import qualified Data.ByteString as BS
import           Lib
import           ParseProgram
import           System.FilePath            (takeBaseName, takeDirectory, (</>))
import           Test.Tasty                 (TestTree, defaultMain, testGroup)
import           Test.Tasty.Golden          (findByExtension, goldenVsStringDiff)
import           Text.Megaparsec
import           Text.Megaparsec.Error      (errorBundlePretty)
import           System.Process

main :: IO ()
main = defaultMain =<< sedReplacementTests

sedReplacementTests :: IO TestTree
sedReplacementTests = testGroup ".sedx golden tests" . fmap aTest <$> findByExtension [".sedx"] "test/examples"
  where
    aTest sedxFile = goldenVsStringDiff
                       testName
                       diff
                       sedOutputGolden -- golden file path
                       (runSedxAndReplace sedxFile sedInput) -- action whose result is tested
      where
        testName = takeDirectory sedxFile
        sedOutputGolden = testName </> "expected"
        sedInput = testName </> "input"
        diff ref new = ["diff", "-u", ref, new]

runSedxAndReplace :: String -> String -> IO ByteString
runSedxAndReplace sedxFile sedInput = do
  prog <- either (fail . errorBundlePretty) pure =<< (parse pProgram sedInput <$> readFile sedxFile)
  input <- readFile sedInput
  BC.pack <$> readProcess "sed" ["-E", printMatchAndSub prog] input