{- For every file foo.u in the current directory write the parse error to foo.message.txt -}
module GenerateErrors where

import qualified Data.Text as Text
import System.Directory (getCurrentDirectory, listDirectory)
import System.FilePath (dropExtension, takeExtension)
import System.IO (putStrLn)
import qualified Unison.Builtin as B
import Unison.Parser (Err)
import qualified Unison.Parsers as P
import Unison.PrintError (prettyParseError)
import Unison.Symbol (Symbol)
import qualified Unison.Util.ColorText as Color
import Unison.Var (Var)
import Prelude

unisonFilesInDir :: FilePath -> IO [String]
unisonFilesInDir p = do
  files <- listDirectory p
  pure $ filter ((==) ".u" . takeExtension) files

unisonFilesInCurrDir :: IO [String]
unisonFilesInCurrDir = getCurrentDirectory >>= unisonFilesInDir

errorFileName :: String -> String
errorFileName n = dropExtension n ++ ".message.txt"

emitAsPlainTextTo :: Var v => String -> Err v -> FilePath -> IO ()
emitAsPlainTextTo src e f = writeUtf8 f plainErr
  where
    plainErr = Color.toPlain $ prettyParseError src e

printError :: Var v => String -> Err v -> IO ()
printError src e = putStrLn $ B.showParseError src e

processFile :: FilePath -> IO ()
processFile f = do
  content <- Text.unpack <$> readUtf8 f
  let res = P.parseFile f content B.names
  case res of
    Left err -> do
      emitAsPlainTextTo content (err :: Err Symbol) (errorFileName f)
      printError content err
    Right _ ->
      putStrLn $
        "Error: " ++ f ++ " parses successfully but none of the files in this directory should parse"

main :: IO ()
main = unisonFilesInCurrDir >>= mapM_ processFile