module Language.Haskell.GhcMod.Check (checkSyntax, check) where

import Control.Applicative
import Control.Monad
import CoreMonad
import Exception
import GHC
import Language.Haskell.GhcMod.ErrMsg
import Language.Haskell.GhcMod.GHCApi
import Language.Haskell.GhcMod.Types
import Prelude

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

-- | Checking syntax of a target file using GHC.
--   Warnings and errors are returned.
checkSyntax :: Options
            -> Cradle
            -> [FilePath]  -- ^ The target files.
            -> IO String
checkSyntax _   _      []    = error "ghc-mod: checkSyntax: No files given"
checkSyntax opt cradle files = unlines <$> withGHC sessionName (check opt cradle files)
  where
    sessionName = case files of
      [file] -> file
      _      -> "MultipleFiles"

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

-- | Checking syntax of a target file using GHC.
--   Warnings and errors are returned.
check :: Options
      -> Cradle
      -> [FilePath]  -- ^ The target files.
      -> Ghc [String]
check _   _      []        = error "ghc-mod: check: No files given"
check opt cradle fileNames = checkIt `gcatch` handleErrMsg ls
  where
    checkIt = do
        readLog <- initializeFlagsWithCradle opt cradle options True
        setTargetFiles fileNames
        checkSlowAndSet
        void $ load LoadAllTargets
        liftIO readLog
    options
      | expandSplice opt = "-w:"   : ghcOpts opt
      | otherwise        = "-Wall" : ghcOpts opt
    ls = lineSeparator opt