-- |
-- Module      :  FileUtils
-- Copyright   :  (C) 2014, 2016-2017  Jens Petersen
--
-- Maintainer  :  Jens Petersen <petersen@fedoraproject.org>
-- Stability   :  alpha
-- Portability :  portable
--
-- Explanation: Command line option processing for building RPM
-- packages.

-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.

module FileUtils (
  filesWithExtension,
  fileWithExtension,
  fileWithExtension_,
  getDirectoryContents_,
  mktempdir,
  withCurrentDirectory,
  withTempDirectory) where

import SysCmd (cmd)

#if (defined(MIN_VERSION_base) && MIN_VERSION_base(4,8,2))
#else
import Control.Applicative ((<$>))
#endif
import Control.Exception (bracket)
import Data.List (isPrefixOf)
import Data.Maybe (isJust)
import System.Directory (getCurrentDirectory, getDirectoryContents,
                         setCurrentDirectory, removeDirectoryRecursive)
import System.FilePath (takeExtension, (</>))

filesWithExtension :: FilePath -> String -> IO [FilePath]
filesWithExtension dir ext =
  filter (\ f -> takeExtension f == ext) <$> getDirectoryContents dir

-- looks in current dir for a unique file with given extension
fileWithExtension :: FilePath -> String -> IO (Maybe FilePath)
fileWithExtension dir ext = do
  files <- filesWithExtension dir ext
  case files of
       [file] -> return $ Just $ dir </> file
       [] -> return Nothing
       _ -> putStrLn ("More than one " ++ ext ++ " file found!") >> return Nothing

-- looks in current dir for a unique file with given extension
fileWithExtension_ :: FilePath -> String -> IO Bool
fileWithExtension_ dir ext =
  isJust <$> fileWithExtension dir ext

mktempdir :: IO FilePath
mktempdir = cmd "mktemp" ["-d", "--tmpdir", "cblrpm.XXXXXXXXXX"]

withTempDirectory :: (FilePath -> IO a) -> IO a
withTempDirectory run = bracket
                        mktempdir
                        removeDirectoryRecursive
                        (\ tmpdir -> do
                            cwd <- getCurrentDirectory
                            setCurrentDirectory tmpdir
                            res <- run cwd
                            setCurrentDirectory cwd
                            return res)

-- getDirectoryContents without hidden files
getDirectoryContents_ :: FilePath -> IO [FilePath]
getDirectoryContents_ dir =
  filter (not . isPrefixOf ".") <$> getDirectoryContents dir

-- from directory-1.2.3.0
withCurrentDirectory :: FilePath -> IO a -> IO a
withCurrentDirectory dir action =
  bracket getCurrentDirectory setCurrentDirectory $ \ _ -> do
    setCurrentDirectory dir
    action