Core.hs

module Network.Telegram.API.Bot.Core (Telegram, telegram, ask', Token (..), Ok, result) where

import "aeson" Data.Aeson (FromJSON (parseJSON), withObject, (.:))
import "base" Control.Exception (SomeException)
import "text" Data.Text (Text)
import "transformers" Control.Monad.Trans.Reader (ReaderT (runReaderT), ask)
import "transformers" Control.Monad.Trans.Except (ExceptT, runExceptT)
import "wreq" Network.Wreq.Session (Session)

newtype Token = Token Text deriving Eq

type Telegram e a = ReaderT (e, (Session, Token)) (ExceptT SomeException IO) a

telegram :: Session -> Token -> e -> Telegram e a -> IO (Either SomeException a)
telegram session token env = runExceptT . flip runReaderT (env, (session, token))

ask' :: Telegram e e
ask' = fst <$> ask

data Ok a = Ok Bool a deriving Show

result :: Ok a -> Maybe a
result (Ok True x) = Just x
result (Ok False _ ) = Nothing

instance FromJSON a => FromJSON (Ok a) where
	parseJSON = withObject "Ok" $ \v ->
		Ok <$> v .: "ok" <*> v .: "result"