{-# LANGUAGE OverloadedStrings #-}

module Language.GraphQL.Serialize
    ( JSON(..)
    ) where

import qualified Data.Aeson as Aeson
import qualified Data.Aeson.Key as Aeson.Key
import Language.GraphQL.Execute.Coerce
import qualified Language.GraphQL.Execute.OrderedMap as OrderedMap
import qualified Language.GraphQL.Type.Out as Out
import qualified Language.GraphQL.Type as Type

newtype JSON = JSON Aeson.Value

instance Aeson.ToJSON JSON where
    toJSON (JSON value) = value

instance Aeson.FromJSON JSON where
    parseJSON = pure . JSON

instance Serialize JSON where
    serialize (Out.ScalarBaseType scalarType) value
        | Type.ScalarType "Int" _ <- scalarType
        , Int int <- value = Just $ JSON $ Aeson.Number $ fromIntegral int
        | Type.ScalarType "Float" _ <- scalarType
        , Float float <- value = Just $ JSON $ Aeson.toJSON float
        | Type.ScalarType "String" _ <- scalarType
        , String string <- value = Just $ JSON $ Aeson.String string
        | Type.ScalarType "ID" _ <- scalarType
        , String string <- value = Just $ JSON $ Aeson.String string
        | Type.ScalarType "Boolean" _ <- scalarType
        , Boolean boolean <- value = Just $ JSON $ Aeson.Bool boolean
    serialize _ (Enum enum) = Just $ JSON $ Aeson.String enum
    serialize _ (List list) = Just $ JSON $ Aeson.toJSON list
    serialize _ (Object object) = Just
        $ JSON
        $ Aeson.object
        $ toJSONKeyValue <$> OrderedMap.toList object
      where
        toJSONKeyValue (key, value) = (Aeson.Key.fromText key, Aeson.toJSON value)
    serialize _ _ = Nothing
    null = JSON Aeson.Null