{-# LANGUAGE CPP #-}

module Check (checkSyntax) where

import Control.Applicative
import Control.Monad
import Data.Char
import Data.List
import Param
import System.Directory
import System.FilePath
import System.IO
import System.Process

----------------------------------------------------------------

checkSyntax :: Options -> String -> IO String
checkSyntax opt file = do
    makeDirectory (outDir opt)
#if __GLASGOW_HASKELL__ >= 611
    (_,_,herr,_) <- runInteractiveProcess (ghc opt) ["--make","-Wall","-fno-warn-unused-do-bind",file,"-outputdir","dist/flymake","-o","dist/flymake/a.out","-i..","-i../..","-i../../..","-i../../../..","-i../../../../.."] Nothing Nothing
#else
    (_,_,herr,_) <- runInteractiveProcess (ghc opt) ["--make","-Wall",file,"-outputdir","dist/flymake","-o","dist/flymake/a.out","-i..","-i../..","-i../../..","-i../../../..","-i../../../../.."] Nothing Nothing
#endif
    hSetBinaryMode herr False
    refine <$> hGetContents herr
  where
    refine = unfoldLines . remove . lines
    remove = filter (\x -> not ("Linking" `isPrefixOf` x))
           . filter (\x -> not ("[" `isPrefixOf` x))
           . filter (/="")

unfoldLines :: [String] -> String
unfoldLines [] = ""
unfoldLines (x:xs) = x ++ unfold xs
  where
    unfold [] = "\n"
    unfold (l:ls)
      | isAlpha (head l)           = ('\n':l) ++ unfold ls
      | otherwise                  = (drop 4 l) ++ "\0" ++ unfold ls

----------------------------------------------------------------

makeDirectory :: FilePath -> IO ()
makeDirectory dir = makeDirectoryRecur $ normalise dir
  where
    makeDirectoryRecur "" = return ()
    makeDirectoryRecur cur = do
      exist <- doesDirectoryExist cur
      let par = takeDirectory cur
      unless exist $ do
          makeDirectoryRecur par
          createDirectory cur