module DownloadDir (
  setDownloadDir)
where

import Control.Monad
import SimpleCmd (error')
import System.Directory (createDirectoryIfMissing,
                         doesDirectoryExist, getHomeDirectory,
                         setCurrentDirectory)
import System.Environment.XDG.UserDir (getUserDir)
import System.FilePath

import Types

setDownloadDir :: Mode -> String -> IO FilePath
setDownloadDir mode subdir = do
  home <- getHomeDirectory
  dlDir <- getUserDir "DOWNLOAD"
  dirExists <- doesDirectoryExist dlDir
  let dryrun =
        case mode of
          ModeCheck -> True
          ModeLocal _ _ -> True
          ModeDownload dr _ -> dr
  -- is this really necessary?
  unless (dryrun || dirExists) $
    when (home == dlDir) $
      error' "HOME directory does not exist!"
  let isoDir = dlDir </> subdir
  isoExists <- doesDirectoryExist isoDir
  dir <-
    if isoExists
    then setCWD isoDir
    else
    if dirExists
      then setCWD dlDir
      else do
      if dryrun
        then return dlDir
        else do
        createDirectoryIfMissing True dlDir
        setCWD dlDir
  let path = makeRelative home dir
  return $ if isRelative path then "~" </> path else path
  where
    setCWD :: FilePath -> IO FilePath
    setCWD dir = do
      setCurrentDirectory dir
      return dir