{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE TypeOperators #-}

-- | Demonstrate input object usage.
module Main (main) where

import Protolude hiding (Enum)

import qualified Data.Aeson as Aeson

import GraphQL
import GraphQL.API
import GraphQL.Resolver (Handler, returns)
import GraphQL.Value (FromValue, toValue)

data DogStuff = DogStuff { _toy :: Text, _likesTreats :: Bool } deriving (Show, Generic)
instance FromValue DogStuff
instance HasAnnotatedInputType DogStuff
instance Defaultable DogStuff where
  -- TODO defaultFor takes a Name which makes sense, but what's the
  -- name for an input object?
  defaultFor _ = Just (DogStuff "shoe" False)

type Query = Object "Query" '[]
  '[ Argument "dogStuff" DogStuff :> Field "description" Text ]

root :: Handler IO Query
root = pure description

description :: DogStuff -> Handler IO Text
description (DogStuff toy likesTreats)
  | likesTreats = returns $ "likes treats and their favorite toy is a " <> toy
  | otherwise = returns $ "their favorite toy is a " <> toy

-- | Show input object usage
--
-- >>> response <- example "{ description(dogStuff: {toy: \"bone\", likesTreats: true}) }"
-- >>> putStrLn $ encode $ toValue response
-- {"data":{"description":"likes treats and their favorite toy is a bone"}}
--
-- >>> response <- example "{ description }"
-- >>> putStrLn $ encode $ toValue response
-- {"data":{"description":"their favorite toy is a shoe"}}
example :: Text -> IO Response
example = interpretAnonymousQuery @Query root


main :: IO ()
main = do
  response <- example "{ description(dogStuff: {_toy: \"bone\", _likesTreats: true}) }"
  putStrLn $ Aeson.encode $ toValue response
  response' <- example "{ description }"
  putStrLn $ Aeson.encode $ toValue response'