module SimplePrompt (
  prompt,
  prompt_,
  yesno
  ) where

import Control.Monad (void)
import Data.Bool (bool)
import Data.List.Extra (lower, trim)

import System.Console.Haskeline

-- FIXME promptNonEmpty
prompt :: String -> IO String
prompt s = do
  runInputT defaultSettings loop
    where
      loop :: InputT IO String
      loop = do
        minput <- getInputLine $ s ++ ": "
        case minput of
          Nothing -> return ""
          Just input -> return input

prompt_ :: String -> IO ()
prompt_ = void <$> prompt

yesno :: Maybe Bool -> String -> IO Bool
yesno mdefault desc = do
  inp <- prompt $ desc ++ "? " ++ maybe "[y/n]" (bool "[y/N]" "[Y/n]") mdefault
  case trim (lower inp) of
    "y" -> return True
    "yes" -> return True
    "n" -> return False
    "no" -> return False
    "" -> maybe (yesno Nothing desc) return mdefault
    _ ->  yesno mdefault desc