module Main where

import System.Posix.Types ()
import System.Posix.Files ()
import System.Posix.Directory ( getWorkingDirectory )
import System.Directory
    ( pathIsSymbolicLink, doesFileExist, getFileSize, doesDirectoryExist )
import System.Environment ()
import Data.Functor ( (<&>) )
import Control.Monad ( (<=<), filterM )
import System.Directory.Extra ( listContents )

listFiles :: FilePath -> IO [FilePath]
listFiles dir = filterM ((return . not) <=< pathIsSymbolicLink) =<< filterM doesFileExist =<< listContents dir

listDirectories :: FilePath -> IO [FilePath]
listDirectories dir = filterM ((return . not) <=< pathIsSymbolicLink) =<< filterM doesDirectoryExist =<< listContents dir

getAllSubpaths :: FilePath -> IO [(FilePath, Integer)]
getAllSubpaths x = do
  sub      <- listDirectories x
  subFiles <- mapM getAllSubpaths sub
  local    <- listFiles x >>= (\y -> mapM getFileSize y <&> zip y)
  return $ local ++ concat subFiles

main :: IO ()
main = do
  a <- getWorkingDirectory
  print =<< getAllSubpaths a