{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE DeriveFunctor #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE GADTs #-}

-- | Internal request and response type for casts and calls

module Control.Eff.Concurrent.Api.Internal
  ( Request (..)
  , Response (..)
  )
where

import           Data.Typeable (Typeable)
import           Data.Proxy
import           Control.Eff.Concurrent.Api
import           Control.Eff.Concurrent.Process

data Request api where
  Call :: forall api apiCallReplyType . (Typeable api, Typeable apiCallReplyType, Typeable (Api api ('Synchronous apiCallReplyType)))
         => ProcessId -> Api api ('Synchronous apiCallReplyType) -> Request api
  Cast :: forall api . (Typeable api, Typeable (Api api 'Asynchronous))
         => Api api 'Asynchronous -> Request api
  Terminate :: Maybe String -> Request api
  deriving Typeable

data Response api apiCallReplyType where
  Response :: (Typeable api, Typeable apiCallReplyType) => Proxy api -> apiCallReplyType -> Response api apiCallReplyType
  deriving Typeable