module Main where

import           Control.Exception
import           Data.Bool
import           Data.Monoid
import           System.FilePath (normalise)

import           Test.Tasty

import qualified Test.Golden.Parser (tests)
import qualified Test.Tag           (tests)
import qualified Test.CTag          (tests)
import qualified Test.ETag          (tests)

import           System.Directory


main ::IO ()
main = do
    -- useing 'IO' 'Monoid' instance
    mGoldenDir
      <- doesGoldenDirectoryExist (normalise "test/golden")
      <> doesGoldenDirectoryExist (normalise "ghc-tags-core/test/golden")

    case mGoldenDir :: First FilePath of
      First Nothing ->
        throwIO $ userError "no 'test/golden' directory found"

      First (Just goldenDir) ->
        defaultMain (tests goldenDir)
  where
    fromBool :: FilePath -> Bool -> First FilePath
    fromBool = bool mempty . First  . Just

    doesGoldenDirectoryExist :: FilePath -> IO (First FilePath)
    doesGoldenDirectoryExist fp = fromBool fp <$> doesDirectoryExist fp


tests :: FilePath -> TestTree
tests goldenTestDir =
    testGroup "GhcTags"
    [ Test.Golden.Parser.tests goldenTestDir
    , Test.Tag.tests
    , Test.CTag.tests
    , Test.ETag.tests
    ]