ghcup-hs/lib/GHCup/Utils/File/Windows.hs

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE FlexibleContexts  #-}
{-# LANGUAGE DataKinds  #-}

{-|
Module      : GHCup.Utils.File.Windows
Description : File and windows APIs
Copyright   : (c) Julian Ospald, 2020
License     : LGPL-3.0
Maintainer  : hasufell@hasufell.de
Stability   : experimental
Portability : Windows

This module handles file and executable handling.
Some of these functions use sophisticated logging.
-}
module GHCup.Utils.File.Windows where

import {-# SOURCE #-} GHCup.Utils ( getLinkTarget, pathIsLink )
import           GHCup.Utils.Dirs
import           GHCup.Utils.File.Common
import           GHCup.Utils.Logger
import           GHCup.Types
import           GHCup.Types.Optics

import           Control.Concurrent
import           Control.DeepSeq
import           Control.Exception.Safe
import           Control.Monad
import           Control.Monad.Reader
import           Data.List
import           Foreign.C.Error
import           GHC.IO.Exception
import           GHC.IO.Handle
import qualified GHC.Unicode                  as U
import           System.Environment
import           System.FilePath
import           System.IO
import qualified System.IO.Error              as IOE
import           System.Process

import qualified System.Win32.Info             as WS
import qualified System.Win32.File             as WS
import qualified Control.Exception             as EX
import qualified Data.ByteString               as BS
import qualified Data.ByteString.Lazy          as BL
import qualified Data.Map.Strict               as Map
import qualified Data.Text                     as T

import qualified Streamly.Internal.Data.Stream.StreamD.Type
                                               as D
import           Streamly.Internal.Data.Unfold.Type hiding ( concatMap )
import           Data.Bits ((.&.))
import qualified Streamly.Prelude              as S
import qualified Streamly.Internal.Data.Unfold as U
import           Streamly.Internal.Control.Concurrent ( withRunInIO )
import           Streamly.Internal.Data.IOFinalizer   ( newIOFinalizer, runIOFinalizer )



toProcessError :: FilePath
               -> [FilePath]
               -> ExitCode
               -> Either ProcessError ()
toProcessError exe args exitcode = case exitcode of
  (ExitFailure xi) -> Left $ NonZeroExit xi exe args
  ExitSuccess -> Right ()


-- | @readCreateProcessWithExitCode@ works exactly like 'readProcessWithExitCode' except that it
-- lets you pass 'CreateProcess' giving better flexibility.
--
-- Note that @Handle@s provided for @std_in@, @std_out@, or @std_err@ via the CreateProcess
-- record will be ignored.
--
-- @since 1.2.3.0
readCreateProcessWithExitCodeBS
    :: CreateProcess
    -> BL.ByteString
    -> IO (ExitCode, BL.ByteString, BL.ByteString) -- ^ exitcode, stdout, stderr
readCreateProcessWithExitCodeBS cp input = do
    let cp_opts = cp {
                    std_in  = CreatePipe,
                    std_out = CreatePipe,
                    std_err = CreatePipe
                  }
    withCreateProcess_ "readCreateProcessWithExitCodeBS" cp_opts $
      \mb_inh mb_outh mb_errh ph ->
        case (mb_inh, mb_outh, mb_errh) of
          (Just inh, Just outh, Just errh) -> do

            out <- BS.hGetContents outh
            err <- BS.hGetContents errh

            -- fork off threads to start consuming stdout & stderr
            withForkWait  (EX.evaluate $ rnf out) $ \waitOut ->
             withForkWait (EX.evaluate $ rnf err) $ \waitErr -> do

              -- now write any input
              unless (BL.null input) $
                ignoreSigPipe $ BL.hPut inh input
              -- hClose performs implicit hFlush, and thus may trigger a SIGPIPE
              ignoreSigPipe $ hClose inh

              -- wait on the output
              waitOut
              waitErr

              hClose outh
              hClose errh

            -- wait on the process
            ex <- waitForProcess ph
            return (ex, BL.fromStrict out, BL.fromStrict err)

          (Nothing,_,_) -> error "readCreateProcessWithExitCodeBS: Failed to get a stdin handle."
          (_,Nothing,_) -> error "readCreateProcessWithExitCodeBS: Failed to get a stdout handle."
          (_,_,Nothing) -> error "readCreateProcessWithExitCodeBS: Failed to get a stderr handle."
 where
  ignoreSigPipe :: IO () -> IO ()
  ignoreSigPipe = EX.handle $ \e -> case e of
                                     IOError { ioe_type  = ResourceVanished
                                             , ioe_errno = Just ioe }
                                       | Errno ioe == ePIPE -> return ()
                                     _ -> throwIO e
  -- wrapper so we can get exceptions with the appropriate function name.
  withCreateProcess_
    :: String
    -> CreateProcess
    -> (Maybe Handle -> Maybe Handle -> Maybe Handle -> ProcessHandle -> IO a)
    -> IO a
  withCreateProcess_ fun c action =
      EX.bracketOnError (createProcess_ fun c) cleanupProcess
                       (\(m_in, m_out, m_err, ph) -> action m_in m_out m_err ph)

-- | Fork a thread while doing something else, but kill it if there's an
-- exception.
--
-- This is important in the cases above because we want to kill the thread
-- that is holding the Handle lock, because when we clean up the process we
-- try to close that handle, which could otherwise deadlock.
--
withForkWait :: IO () -> (IO () ->  IO a) -> IO a
withForkWait async' body = do
  waitVar <- newEmptyMVar :: IO (MVar (Either SomeException ()))
  mask $ \restore -> do
    tid <- forkIO $ try (restore async') >>= putMVar waitVar
    let wait' = takeMVar waitVar >>= either throwIO return
    restore (body wait') `EX.onException` killThread tid


-- | Execute the given command and collect the stdout, stderr and the exit code.
-- The command is run in a subprocess.
executeOut :: MonadIO m
           => FilePath          -- ^ command as filename, e.g. 'ls'
           -> [String]          -- ^ arguments to the command
           -> Maybe FilePath    -- ^ chdir to this path
           -> m CapturedProcess
executeOut path args chdir = do
  cp <- createProcessWithMingwPath ((proc path args){ cwd = chdir })
  (exit, out, err) <- liftIO $ readCreateProcessWithExitCodeBS cp ""
  pure $ CapturedProcess exit out err


execLogged :: ( MonadReader env m
              , HasDirs env
              , HasLog env
              , HasSettings env
              , MonadIO m
              , MonadThrow m)
           => FilePath         -- ^ thing to execute
           -> [String]         -- ^ args for the thing
           -> Maybe FilePath   -- ^ optionally chdir into this
           -> FilePath         -- ^ log filename (opened in append mode)
           -> Maybe [(String, String)] -- ^ optional environment
           -> m (Either ProcessError ())
execLogged exe args chdir lfile env = do
  Dirs {..} <- getDirs
  logDebug $ T.pack $ "Running " <> exe <> " with arguments " <> show args
  let stdoutLogfile = fromGHCupPath logsDir </> lfile <> ".stdout.log"
      stderrLogfile = fromGHCupPath logsDir </> lfile <> ".stderr.log"
  cp <- createProcessWithMingwPath ((proc exe args)
    { cwd = chdir
    , env = env
    , std_in = CreatePipe
    , std_out = CreatePipe
    , std_err = CreatePipe
    })
  fmap (toProcessError exe args)
    $ liftIO
    $ withCreateProcess cp
    $ \_ mout merr ph ->
        case (mout, merr) of
          (Just cStdout, Just cStderr) -> do
            withForkWait (tee stdoutLogfile cStdout) $ \waitOut ->
              withForkWait (tee stderrLogfile cStderr) $ \waitErr -> do
                waitOut
                waitErr
            waitForProcess ph
          _ -> fail "Could not acquire out/err handle"

 where
  tee :: FilePath -> Handle -> IO ()
  tee logFile handle' = go
    where
      go = do
        some <- BS.hGetSome handle' 512
        if BS.null some
          then pure ()
          else do
            void $ BS.appendFile logFile some
            -- subprocess stdout also goes to stderr for logging
            void $ BS.hPut stderr some
            go


-- | Thin wrapper around `executeFile`.
exec :: MonadIO m
     => FilePath       -- ^ thing to execute
     -> [FilePath]     -- ^ args for the thing
     -> Maybe FilePath   -- ^ optionally chdir into this
     -> Maybe [(String, String)] -- ^ optional environment
     -> m (Either ProcessError ())
exec exe args chdir env = do
  cp <- createProcessWithMingwPath ((proc exe args) { cwd = chdir, env = env })
  exit_code <- liftIO $ withCreateProcess cp $ \_ _ _ p -> waitForProcess p
  pure $ toProcessError exe args exit_code


-- | Thin wrapper around `executeFile`.
execShell :: MonadIO m
          => FilePath       -- ^ thing to execute
          -> [FilePath]     -- ^ args for the thing
          -> Maybe FilePath   -- ^ optionally chdir into this
          -> Maybe [(String, String)] -- ^ optional environment
          -> m (Either ProcessError ())
execShell exe args chdir env = do
  let cmd = exe <> " " <> concatMap (' ':) args
  cp <- createProcessWithMingwPath ((shell cmd) { cwd = chdir, env = env })
  exit_code <- liftIO $ withCreateProcess cp $ \_ _ _ p -> waitForProcess p
  pure $ toProcessError cmd [] exit_code


chmod_755 :: MonadIO m => FilePath -> m ()
chmod_755 fp =
  let perm = setOwnerWritable True emptyPermissions
  in liftIO $ setPermissions fp perm


createProcessWithMingwPath :: MonadIO m
                          => CreateProcess
                          -> m CreateProcess
createProcessWithMingwPath cp = do
  msys2Dir <- liftIO ghcupMsys2Dir
  cEnv <- Map.fromList <$> maybe (liftIO getEnvironment) pure (env cp)
  let mingWPaths = [msys2Dir </> "usr" </> "bin"
                   ,msys2Dir </> "mingw64" </> "bin"]
      paths = ["PATH", "Path"]
      curPaths = (\x -> maybe [] splitSearchPath (Map.lookup x cEnv)) =<< paths
      newPath = intercalate [searchPathSeparator] (mingWPaths ++ curPaths)
      envWithoutPath = foldr (\x y -> Map.delete x y) cEnv paths
      envWithNewPath = Map.insert "Path" newPath envWithoutPath
  liftIO $ setEnv "Path" newPath
  pure $ cp { env = Just $ Map.toList envWithNewPath }

ghcupMsys2Dir :: IO FilePath
ghcupMsys2Dir =
  lookupEnv "GHCUP_MSYS2" >>= \case
    Just fp -> pure fp
    Nothing -> do
      baseDir <- liftIO ghcupBaseDir
      pure (fromGHCupPath baseDir </> "msys64")

-- | Checks whether the binary is a broken link.
isBrokenSymlink :: FilePath -> IO Bool
isBrokenSymlink fp = do
  b <- pathIsLink fp
  if b
  then do
    tfp <- getLinkTarget fp
    not <$> doesPathExist
      -- this drops 'symDir' if 'tfp' is absolute
      (takeDirectory fp </> tfp)
  else pure False


copyFile :: FilePath   -- ^ source file
         -> FilePath   -- ^ destination file
         -> Bool       -- ^ fail if file exists
         -> IO ()
copyFile = WS.copyFile

deleteFile :: FilePath -> IO ()
deleteFile = WS.deleteFile

install :: FilePath -> FilePath -> Bool -> IO ()
install = copyFile

removeEmptyDirectory :: FilePath -> IO ()
removeEmptyDirectory = WS.removeDirectory


unfoldDirContents :: (S.MonadAsync m, MonadIO m, MonadCatch m, MonadMask m) => Unfold m FilePath (WS.FileAttributeOrFlag, FilePath)
unfoldDirContents = U.bracket alloc dealloc (Unfold step return)
 where
  {-# INLINE [0] step #-}
  step (_, False, _, _) = return D.Stop
  step (topdir, True, h, fd) = flip onException (liftIO $ WS.findClose h) $ do
    f <- liftIO $ WS.getFindDataFileName fd
    more <- liftIO $ WS.findNextFile h fd

    -- can't get file attribute from FindData yet (needs Win32 PR)
    fattr <- liftIO $ WS.getFileAttributes (topdir </> f)

    if | f == "." || f == ".." -> return $ D.Skip             (topdir, more, h, fd)
       | otherwise             -> return $ D.Yield (fattr, f) (topdir, more, h, fd)

  alloc topdir = do
    query <- liftIO $ furnishPath (topdir </> "*")
    (h, fd) <- liftIO $ WS.findFirstFile query
    pure (topdir, True, h, fd)

  dealloc (_, _, fd, _) = liftIO $ WS.findClose fd


getDirectoryContentsRecursiveDFSUnsafe :: (MonadCatch m, S.MonadAsync m, MonadMask m, S.IsStream t)
                                       => FilePath
                                       -> t m FilePath
getDirectoryContentsRecursiveDFSUnsafe fp = go ""
 where
  isDir attrs = attrs .&. WS.fILE_ATTRIBUTE_DIRECTORY /= 0

  go cd = flip S.concatMap (S.unfold unfoldDirContents (fp </> cd)) $ \(t, f) ->
    if | isDir t   -> go (cd </> f)
       | otherwise -> pure (cd </> f)


getDirectoryContentsRecursiveUnfold :: (MonadCatch m, S.MonadAsync m, MonadMask m) => Unfold m FilePath FilePath
getDirectoryContentsRecursiveUnfold = Unfold step init'
 where
  {-# INLINE [0] step #-}
  step (_, Nothing, []) = return D.Stop

  step (topdir, state@(Just (cdir, (h, findData, ref))), dirs) = flip onException (runIOFinalizer ref) $ do
    f <- liftIO $ WS.getFindDataFileName findData

    more <- liftIO $ WS.findNextFile h findData
    when (not more) $ runIOFinalizer ref
    let nextState = if more then state else Nothing

    -- can't get file attribute from FindData yet (needs Win32 PR)
    fattr <- liftIO $ WS.getFileAttributes (topdir </> cdir </> f)

    if | f == "." || f == ".." -> return $ D.Skip               (topdir, nextState, dirs)
       | isDir fattr           -> return $ D.Skip               (topdir, nextState, (cdir </> f):dirs)
       | otherwise             -> return $ D.Yield (cdir </> f) (topdir, nextState, dirs)

  step (topdir, Nothing, dir:dirs) = do
    (h, findData, ref) <- acquire (topdir </> dir)
    return $ D.Skip (topdir, Just (dir, (h, findData, ref)), dirs)

  init' topdir = do
    (h, findData, ref) <- acquire topdir
    return (topdir, Just ("", (h, findData, ref)), [])

  isDir attrs = attrs .&. WS.fILE_ATTRIBUTE_DIRECTORY /= 0

  acquire dir = do
    query <- liftIO $ furnishPath (dir </> "*")
    withRunInIO $ \run -> mask_ $ run $ do
        (h, findData) <- liftIO $ WS.findFirstFile query
        ref <- newIOFinalizer (liftIO $ WS.findClose h)
        return (h, findData, ref)


getDirectoryContentsRecursiveBFSUnsafe :: (MonadMask m, MonadIO m, S.MonadAsync m)
                                       => FilePath
                                       -> S.SerialT m FilePath
getDirectoryContentsRecursiveBFSUnsafe = S.unfold getDirectoryContentsRecursiveUnfold



    --------------------------------------
    --[ Inlined from directory package ]--
    --------------------------------------


furnishPath :: FilePath -> IO FilePath
furnishPath path =
  (toExtendedLengthPath <$> rawPrependCurrentDirectory path)
    `IOE.catchIOError` \ _ ->
      pure path


toExtendedLengthPath :: FilePath -> FilePath
toExtendedLengthPath path
  | isRelative path = simplifiedPath
  | otherwise =
      case simplifiedPath of
        '\\' : '?'  : '?' : '\\' : _ -> simplifiedPath
        '\\' : '\\' : '?' : '\\' : _ -> simplifiedPath
        '\\' : '\\' : '.' : '\\' : _ -> simplifiedPath
        '\\' : subpath@('\\' : _) -> "\\\\?\\UNC" <> subpath
        _ -> "\\\\?\\" <> simplifiedPath
  where simplifiedPath = simplify path


simplify :: FilePath -> FilePath
simplify = simplifyWindows

simplifyWindows :: FilePath -> FilePath
simplifyWindows "" = ""
simplifyWindows path =
  case drive' of
    "\\\\?\\" -> drive' <> subpath
    _ -> simplifiedPath
  where
    simplifiedPath = joinDrive drive' subpath'
    (drive, subpath) = splitDrive path
    drive' = upperDrive (normaliseTrailingSep (normalisePathSeps drive))
    subpath' = appendSep . avoidEmpty . prependSep . joinPath .
               stripPardirs . expandDots . skipSeps .
               splitDirectories $ subpath

    upperDrive d = case d of
      c : ':' : s | U.isAlpha c && all isPathSeparator s -> U.toUpper c : ':' : s
      _ -> d
    skipSeps = filter (not . (`elem` (pure <$> pathSeparators)))
    stripPardirs | pathIsAbsolute || subpathIsAbsolute = dropWhile (== "..")
                 | otherwise = id
    prependSep | subpathIsAbsolute = (pathSeparator :)
               | otherwise = id
    avoidEmpty | not pathIsAbsolute
                 && (null drive || hasTrailingPathSep) -- prefer "C:" over "C:."
                 = emptyToCurDir
               | otherwise = id
    appendSep p | hasTrailingPathSep
                  && not (pathIsAbsolute && null p)
                  = addTrailingPathSeparator p
                | otherwise = p
    pathIsAbsolute = not (isRelative path)
    subpathIsAbsolute = any isPathSeparator (take 1 subpath)
    hasTrailingPathSep = hasTrailingPathSeparator subpath

emptyToCurDir :: FilePath -> FilePath
emptyToCurDir ""   = "."
emptyToCurDir path = path

normaliseTrailingSep :: FilePath -> FilePath
normaliseTrailingSep path = do
  let path' = reverse path
  let (sep, path'') = span isPathSeparator path'
  let addSep = if null sep then id else (pathSeparator :)
  reverse (addSep path'')

normalisePathSeps :: FilePath -> FilePath
normalisePathSeps p = (\ c -> if isPathSeparator c then pathSeparator else c) <$> p

expandDots :: [FilePath] -> [FilePath]
expandDots = reverse . go []
  where
    go ys' xs' =
      case xs' of
        [] -> ys'
        x : xs ->
          case x of
            "." -> go ys' xs
            ".." ->
              case ys' of
                [] -> go (x : ys') xs
                ".." : _ -> go (x : ys') xs
                _ : ys -> go ys xs
            _ -> go (x : ys') xs

rawPrependCurrentDirectory :: FilePath -> IO FilePath
rawPrependCurrentDirectory path
  | isRelative path =
    ((`ioeAddLocation` "prependCurrentDirectory") .
     (`IOE.ioeSetFileName` path)) `IOE.modifyIOError` do
      getFullPathName path
  | otherwise = pure path

ioeAddLocation :: IOError -> String -> IOError
ioeAddLocation e loc = do
  IOE.ioeSetLocation e newLoc
  where
    newLoc = loc <> if null oldLoc then "" else ":" <> oldLoc
    oldLoc = IOE.ioeGetLocation e

getFullPathName :: FilePath -> IO FilePath
getFullPathName path =
  fromExtendedLengthPath <$> WS.getFullPathName (toExtendedLengthPath path)

fromExtendedLengthPath :: FilePath -> FilePath
fromExtendedLengthPath ePath =
  case ePath of
    '\\' : '\\' : '?' : '\\' : path ->
      case path of
        'U' : 'N' : 'C' : subpath@('\\' : _) -> "\\" <> subpath
        drive : ':' : subpath
          -- if the path is not "regular", then the prefix is necessary
          -- to ensure the path is interpreted literally
          | U.isAlpha drive && U.isAscii drive && isPathRegular subpath -> path
        _ -> ePath
    _ -> ePath
  where
    isPathRegular path =
      not ('/' `elem` path ||
           "." `elem` splitDirectories path ||
           ".." `elem` splitDirectories path)