import Control.Monad(ap, replicateM, filterM, liftM)
import Data.IORef
import Control.Applicative
import Options.Applicative

data Command = Command
  { l    :: Bool,
    c    :: Bool,
    m    :: Bool,
    w    :: Bool,
    f    :: Input}

data Input
    = FileInput FilePath
    | StdInput

readCommand :: Parser Command
readCommand = Command
    <$> switch
        ( long "lines"
       <> short 'l'
       <> help "--вывести количество строк" )
    <*> switch
        ( long "bytes"
       <> short 'c'
       <> help "--вывести количество байт" )
    <*> switch
        ( long "chars"
       <> short 'm'
       <> help "--вывести количество символов" )
    <*> switch
        ( long "words"
       <> short 'w'
       <> help "--вывести количество слов" )
    <*> ( (FileInput <$> argument str ( metavar "FILE" <> help "Input file" ))
       <|> (StdInput <$ pure ()))


runCommand :: Command -> IO ()
runCommand (cm@(Command l c m w (FileInput f))) = do
    str <- readFile f
    writeAns cm str
runCommand (cm@(Command l c m w StdInput)) = do
    str <- getLine
    writeAns cm str

writeIf :: Bool -> Int -> IO ()
writeIf p x = if p then print x else return ()

writeAns :: Command -> String -> Int
writeAns (Command l c m w _) str = do
    l' <- wcl str
    writeIf l l'
    c' <- wcc str
    writeIf c c'
    w' <- wcw str
    writeIf w w'

wcc ::  String -> Int
wcc s = length s

wcl ::  String -> Int
wcl s = length . lines s

wcw ::  String -> Int
wcw s = length . words s

main :: IO ()
main = runCommand =<< execParser opts
  where
    opts = info (readCommand <**> helper)
      ( fullDesc
     <> header "[OPTIONS] <filename>` где `[OPTIONS]` могут быть:" )