module Network.Telegram.API.Bot.Object.Update (Update (..), chat) where

import "aeson" Data.Aeson (FromJSON (parseJSON), withObject, (.:))
import "aeson" Data.Aeson.Types (Object, Parser)
import "base" Control.Applicative (Alternative ((<|>)))
import "lens" Control.Lens (Lens')

import Network.Telegram.API.Bot.Object.Callback (Callback (Datatext))
import Network.Telegram.API.Bot.Object.Chat (Chat)
import Network.Telegram.API.Bot.Object.Message (Message (Textual, Command))
import Network.Telegram.API.Bot.Property.Identifiable
	(Identifiable (identificator), Identificator)

data Update
	= Incoming Int Message
	| Query Int Callback
	deriving Show

type instance Identificator Update = Int

instance Identifiable Update where
	identificator (Incoming i _) = i
	identificator (Query i _) = i

instance FromJSON Update where
	parseJSON = withObject "Update" $ \v -> query v <|> incoming v where

		query :: Object -> Parser Update
		query v = Query <$> v .: "update_id" <*> v .: "callback_query"

		incoming :: Object -> Parser Update
		incoming v = Incoming <$> v .: "update_id" <*> v .: "message"

chat :: Lens' Update Chat
chat f (Incoming upd_id (Command msg_id chat_ from cmd)) =
	(\chat' -> Incoming upd_id (Command msg_id chat' from cmd)) <$> f chat_
chat f (Incoming upd_id (Textual msg_id chat_ from txt)) =
	(\chat' -> Incoming upd_id (Textual msg_id chat' from txt)) <$> f chat_
chat f (Query upd_id (Datatext cq_id (Command msg_id chat_ from cmd) dttxt)) =
	(\chat' -> Query upd_id (Datatext cq_id (Command msg_id chat' from cmd) dttxt)) <$> f chat_
chat f (Query upd_id (Datatext cq_id (Textual msg_id chat_ from txt) dttxt)) =
	(\chat' -> Query upd_id (Datatext cq_id (Textual msg_id chat' from txt) dttxt)) <$> f chat_