{-# LANGUAGE MultiParamTypeClasses #-}
module Affection.MessageBus.Class where

import Affection.MessageBus.Message
import Affection.Types

class (Message m) => Participant prt m where
  -- | get the outbound 'Channel' of the 'Participant'
  partChannel
    :: prt       -- ^ The 'Participant'
    -> Channel m -- ^ Outbound 'Channel'

  -- | Initialize the 'Participant' with an inbound 'Channel'
  partInit
    :: Channel m        -- ^ Inbound 'Channel' the 'Participant' will listen to
    -> Affection sd prt -- ^ The constructed and initialized 'Participant'

  -- Get the 'Participant' to listen to its inbound 'Channel'
  partListen
    :: prt                    -- ^ The 'Participant'
    -> Affection sd (Maybe m) -- ^ The optional 'Message' peeked from the 'Channel'

  -- Get the 'Participant' to emit a Message on its outbound 'Channel'
  partEmit
    :: prt             -- ^ The 'Participant'
    -> m               -- ^ The 'Message' to emit
    -> Affection sd ()

-- data Envelope = Envelope
--   { envFrom    :: (Participant a _) => a
--   , envTo      :: (Participant b _) => b
--   , envMessage :: (Message msg) => msg
--   }