{-# LANGUAGE FlexibleContexts #-}
module Execute
       ( updateMap
       , executeEcho
       , executeCd
       , executePwd
       , executeExit
       ) where

import Control.Monad.Reader (MonadIO, liftIO)
import Data.Map (Map, empty, insert)
import Control.Monad.State (MonadState, get, modify)
import Control.Monad.Except (MonadError)
import Action
import Exception
import System.Posix.Directory (getWorkingDirectory, changeWorkingDirectory)
import System.Exit (exitWith, ExitCode(ExitSuccess))

updateMap :: ( MonadState (Map String String)  m
             , MonadError Exception m
             ) => [Action] -> m ()
updateMap [] = return ()
updateMap ((Assigment key value) : t) = do
                                        modify $ insert key value
                                        updateMap t



executeEcho :: MonadIO m => String -> m ()
executeEcho s = liftIO $ print s

executeCd :: MonadIO m => String -> m ()
executeCd s = liftIO $ changeWorkingDirectory s

executePwd :: MonadIO m => m ()
executePwd = liftIO $ do
                      path <- getWorkingDirectory
                      print path

executeExit :: MonadIO m => m ()
executeExit = liftIO $ exitWith ExitSuccess