request :: ∀ a b. WriteForeign a => Decode b => Method.Method -> Request a -> Aff (M.Response b)
request method req = 
  liftAff $ 
    Affjax.request 
      (Affjax.defaultRequest 
        { method = Left method
        , headers = maybe [] (\t -> [RequestHeader.RequestHeader "auth.sig" t]) req.token
        , url = req.url
        , content = Just $ RequestBody.string $ writeJSON req.content
        , responseFormat = ResponseFormat.string
        }
      ) >>= case _ of

    Left error -> 
      pure $ M.ResponseError (ApiTransportError (Affjax.printError error))
    Right response -> pure case response.status of
      StatusCode 200 -> case readResponse (JSON response.body) of
        Just content -> content
        Nothing -> M.ResponseError (ApiError response.body)
      _ -> M.ResponseError (ApiError if response.body == "" then response.statusText else response.body)

-- The response type is being use by the helper to parse the api results
data Response a
  = ResponseError ApiError
  | Response a
 
-- to make it even more readable, we just create an alias for each api response
type GetNotesResponse = Response (Array Note)

derive instance Generic (Response a) _
derive instance Functor Response
instance Encode a => Encode (Response a) where
  encode s = genericEncode defaultOptions s
instance Decode a => Decode (Response a) where
  decode s = genericDecode defaultOptions s
instance Decode a => ReadForeign (Response a) where
  readImpl = decode
instance Encode a => WriteForeign (Response a) where
  writeImpl = encode 

getNotes :: String -> HTTPure.ResponseM
getNotes token = do
  notes <- DB.getNotes token
  HTTPure.ok $ JSON.writeJSON (M.Response notes)

-- add to the ActionAff the request action
| GetNotes String (M.GetNotesResponse -> next)
-- just call the ajax helper
GetNotes token next -> do
    notes <- Ajax.get { url: "/api/notes", token: Just token, content: { } }
    pure $ next notes
	
-- add the return to the the Actions
| NotesLoaded M.GetNotesResponse
-- the loaded action will be matched as an error, or a response
NotesLoaded reponse -> case reponse of
    M.ResponseError e -> purely model { error = Just (show e) }
    M.Response r -> purely model { notes = r }

-- add the new ActionAff event to load the notes in the init
app ∷ App.App ActionAff (Const Void) Model Action
app = { update, render, subs: const mempty, init: {model: initModel, effects: App.lift ((GetNotes "token") NotesLoaded)} }