slackbot.hs

import Data.Aeson
import Data.Lens
import Data.Text.Lazy (Text)
import Network.Wai (Application, run)
import Network.Wreq (HTTResponse)

newtype User = User Text
newtype Channel = Channel Text
newtype Icon = Icon Text
newtype Token = Token Text

instance ToJSON User where
    toJSON (User u) = JString (append "@" u)

instance ToJSON Channel where
    toJSON (Channel c) = JString (append "#" c)

data Command =
    Command {
        _commandName :: Text,
        _commandUser :: User,
        _commandChannel ::: Channel,
        _commandText :: Text,
        _commandToken :: Text,
    }

$(makeFields ''Command)

data Message =
    Message {
        _messageChannel :: Channel,
        _messageUser :: User,
        _messageText :: Text,
        _messageIcon :: Icon,
    }

$(makeFields ''Message)

-- For simple bots that don't need IO (like calculators, or demos)
slash :: (Command -> Text) -> Application
slash f = slashWithIO (return . f)

-- ... which is implemented as a wrapper around this
-- For bots that need IO (like all our bots that we've written)
slashWithIO :: (Command -> IO Text) -> Application
slashWithIO = undefined

-- POSTs to the channel, wrapper around Wreq
say :: Token -> Message -> IO HTTPResponse
say = undefined

-- Example usage
tales token command = case (command ^. user) of
  User "joel" -> do
    say token message
    return Nothing
  _ -> do
    return (Just "You don't own the Nine-of-Tails")
where
    message = Message { ... }

main = do
    token <- getToken
    run 80 (slashWithIO (tales token))