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{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Test.StarWars.Schema
( schema
) where
import Control.Monad.Trans.Reader (asks)
import Control.Monad.Trans.Except (throwE)
import Control.Monad.Trans.Class (lift)
import Data.Functor.Identity (Identity)
import qualified Data.HashMap.Strict as HashMap
import Data.Maybe (catMaybes)
import Data.Text (Text)
import Language.GraphQL.Trans
import Language.GraphQL.Type
import qualified Language.GraphQL.Type.In as In
import qualified Language.GraphQL.Type.Out as Out
import Test.StarWars.Data
import Prelude hiding (id)
-- See https://github.com/graphql/graphql-js/blob/master/src/__tests__/starWarsSchema.js
schema :: Schema Identity
schema = Schema { query = queryType, mutation = Nothing }
where
queryType = Out.ObjectType "Query" Nothing [] $ HashMap.fromList
[ ("hero", heroField)
, ("human", humanField)
, ("droid", droidField)
]
heroArguments = HashMap.singleton "episode"
$ In.Argument Nothing (In.NamedEnumType episodeEnum) Nothing
heroField =
Out.Field Nothing (Out.NamedObjectType heroObject) heroArguments hero
humanArguments = HashMap.singleton "id"
$ In.Argument Nothing (In.NonNullScalarType string) Nothing
humanField =
Out.Field Nothing (Out.NamedObjectType heroObject) humanArguments human
droidField = Out.Field Nothing (Out.NamedObjectType droidObject) mempty droid
heroObject :: Out.ObjectType Identity
heroObject = Out.ObjectType "Human" Nothing [] $ HashMap.fromList
[ ("id", idFieldType)
, ("name", nameFieldType)
, ("friends", friendsFieldType)
, ("appearsIn", appearsInField)
, ("homePlanet", homePlanetFieldType)
, ("secretBackstory", secretBackstoryFieldType)
, ("__typename", typenameFieldType)
]
where
homePlanetFieldType = Out.Field Nothing (Out.NamedScalarType string) mempty
$ idField "homePlanet"
droidObject :: Out.ObjectType Identity
droidObject = Out.ObjectType "Droid" Nothing [] $ HashMap.fromList
[ ("id", idFieldType)
, ("name", nameFieldType)
, ("friends", friendsFieldType)
, ("appearsIn", appearsInField)
, ("primaryFunction", primaryFunctionFieldType)
, ("secretBackstory", secretBackstoryFieldType)
, ("__typename", typenameFieldType)
]
where
primaryFunctionFieldType = Out.Field Nothing (Out.NamedScalarType string) mempty
$ idField "primaryFunction"
typenameFieldType :: Out.Field Identity
typenameFieldType = Out.Field Nothing (Out.NamedScalarType string) mempty
$ idField "__typename"
idFieldType :: Out.Field Identity
idFieldType = Out.Field Nothing (Out.NamedScalarType id) mempty
$ idField "id"
nameFieldType :: Out.Field Identity
nameFieldType = Out.Field Nothing (Out.NamedScalarType string) mempty
$ idField "name"
friendsFieldType :: Out.Field Identity
friendsFieldType = Out.Field Nothing (Out.ListType $ Out.NamedObjectType droidObject) mempty
$ idField "friends"
appearsInField :: Out.Field Identity
appearsInField = Out.Field (Just description) fieldType mempty
$ idField "appearsIn"
where
fieldType = Out.ListType $ Out.NamedEnumType episodeEnum
description = "Which movies they appear in."
secretBackstoryFieldType :: Out.Field Identity
secretBackstoryFieldType = Out.Field Nothing (Out.NamedScalarType string) mempty
$ String <$> secretBackstory
idField :: Text -> ResolverT Identity Value
idField f = do
v <- ResolverT $ lift $ asks values
let (Object v') = v
pure $ v' HashMap.! f
episodeEnum :: EnumType
episodeEnum = EnumType "Episode" (Just description)
$ HashMap.fromList [newHope, empire, jedi]
where
description = "One of the films in the Star Wars Trilogy"
newHope = ("NEW_HOPE", EnumValue $ Just "Released in 1977.")
empire = ("EMPIRE", EnumValue $ Just "Released in 1980.")
jedi = ("JEDI", EnumValue $ Just "Released in 1983.")
hero :: ResolverT Identity Value
hero = do
episode <- argument "episode"
pure $ character $ case episode of
Enum "NEW_HOPE" -> getHero 4
Enum "EMPIRE" -> getHero 5
Enum "JEDI" -> getHero 6
_ -> artoo
human :: ResolverT Identity Value
human = do
id' <- argument "id"
case id' of
String i -> do
humanCharacter <- lift $ return $ getHuman i >>= Just
case humanCharacter of
Nothing -> pure Null
Just e -> pure $ character e
_ -> ResolverT $ throwE "Invalid arguments."
droid :: ResolverT Identity Value
droid = do
id' <- argument "id"
case id' of
String i -> character <$> getDroid i
_ -> ResolverT $ throwE "Invalid arguments."
character :: Character -> Value
character char = Object $ HashMap.fromList
[ ("id", String $ id_ char)
, ("name", String $ name_ char)
, ("friends", List $ character <$> getFriends char)
, ("appearsIn", List $ Enum <$> catMaybes (getEpisode <$> appearsIn char))
, ("homePlanet", String $ either mempty homePlanet char)
, ("__typename", String $ typeName char)
]
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