-----------------------------------------------------------------------------
-- |
-- Module      :  System.Init
-- Copyright   :  (c) 2020-2021 EMQ Technologies Co., Ltd.
-- License     :  BSD-style (see the LICENSE file)
--
-- Maintainer  :  Feng Lee, feng@emqx.io
--                Yang M, yangm@emqx.io
-- Stability   :  experimental
-- Portability :  portable
--
-- The System Init module.
--
-----------------------------------------------------------------------------
module System.Init
  ( Arguments
  , InternalStatus(..)
  , Flags
  , ProvidedStatus
  , BootMode(..)
  , boot
  , getArguments
  , getArgument
  , getPlainArguments
  , restart
  , restartWith
  , reboot
  , stop
  , stopWith
  ) where

import Control.Monad (IO)
import Data.Maybe (Maybe)
import Data.Unit (Unit)
import Foreign (ffiIO0, ffiIO1)

type Arguments = [String]

type Flags = [(Atom, Arguments)]

data InternalStatus = Starting | Started | Stopping

type ProvidedStatus = String

data BootMode = Embedded | Interactive

foreign import getArguments :: IO [Flags]
-- getArguments = ffiIO0 :init :get_arguments

foreign import getArgument
  :: String -> IO (Maybe Arguments)

getPlainArguments :: IO Arguments
getPlainArguments = ffiIO0 :init :get_plain_arguments

foreign import getStatus
  :: IO (InternalStatus, ProvidedStatus)

boot :: [Binary] -> IO ()
boot = ffiIO1 :init :boot

restart :: IO ()
restart = ffiIO0 :init :restart

foreign import restartWith :: BootMode -> IO ()

reboot :: IO ()
reboot = ffiIO0 :init :reboot

stop :: IO ()
stop = ffiIO0 :init :stop

stopWith :: Integer -> IO ()
stopWith = ffiIO1 :init :stop

{-
  halt() -> no_return()
  halt(Status) -> no_return()
  halt(Status, Options) -> no_return()
  Status must be a non-negative integer, a string, or the atom abort.
    Halts the Erlang runtime system. Has no return value.
      Depending on Status, the following occurs:
-}