playing around with monads in servant

gistfile1.hs

{-# LANGUAGE DataKinds, TypeOperators, OverloadedStrings #-}

import Servant.API
import Servant.Server
import Control.Monad.Trans.Either
import Data.Proxy
import Data.Aeson

data AuthResult = AuthResult { sessionCookie :: String, message :: String }
instance ToJSON AuthResult where
        toJSON = undefined

data Whatever = Whatever

data HelloResponse = HelloResponse
instance ToJSON HelloResponse where
        toJSON = undefined

newtype SessionMonad a = SessionMonad (IO a)


type AuthAPI = "login" :> QueryParam "user" String :> QueryParam "pass" String :> Get AuthResult
          :<|> "logout" :> Get AuthResult

data AuthDB = AuthDB

runSession :: AuthDB -> SessionMonad a -> IO a
runSession _ (SessionMonad a) = a


loginHandler :: Maybe String -> Maybe String -> EitherT (Int,String) SessionMonad AuthResult
loginHandler = undefined

logoutHandler :: EitherT (Int,String) SessionMonad AuthResult
logoutHandler = undefined

--authHandler :: (Maybe String -> Maybe String -> EitherT (Int,String) SessionMonad AuthResult)
--          :<|> (EitherT (Int,String) SessionMonad AuthResult)
authHandler :: ServerT AuthAPI SessionMonad
authHandler = loginHandler :<|> logoutHandler

type MyProtectedAPI = "auth" :> AuthAPI
                  :<|> "hello" :> Get HelloResponse

myProtectedAPI :: Proxy MyProtectedAPI
myProtectedAPI = Proxy

helloHandler :: EitherT (Int,String) SessionMonad HelloResponse
helloHandler = undefined

myProtectedHandler :: ServerT MyProtectedAPI SessionMonad
myProtectedHandler = authHandler :<|> helloHandler

type MyOpenAPI = "public" :> Get Whatever

myOpenHandler :: Server MyOpenAPI
myOpenHandler = return Whatever

type MyAPI = MyProtectedAPI :<|> MyOpenAPI

myHandler :: AuthDB -> Server MyAPI
myHandler authDb = enter myProtectedAPI (runSession authDb) myProtectedHandler :<|> myOpenHandler