{-# LANGUAGE OverloadedStrings #-}
module Language.GraphQL.Execute
( execute
) where
import Control.Monad.IO.Class (MonadIO)
import qualified Data.List.NonEmpty as NE
import Data.List.NonEmpty (NonEmpty((:|)))
import qualified Data.Aeson as Aeson
import qualified Language.GraphQL.AST as AST
import qualified Language.GraphQL.AST.Core as AST.Core
import qualified Language.GraphQL.AST.Transform as Transform
import Language.GraphQL.Error
import Language.GraphQL.Schema (Schema)
import qualified Language.GraphQL.Schema as Schema
execute
:: MonadIO m
=> Schema m -> Schema.Subs -> AST.Document -> m Aeson.Value
execute schema subs doc =
maybe transformError (document schema) $ Transform.document subs doc
where
transformError = return $ singleError "Schema transformation error."
document :: MonadIO m => Schema m -> AST.Core.Document -> m Aeson.Value
document schema (op :| []) = operation schema op
document _ _ = return $ singleError "Multiple operations not supported yet."
operation :: MonadIO m => Schema m -> AST.Core.Operation -> m Aeson.Value
operation schema (AST.Core.Query flds)
= runCollectErrs (Schema.resolve (NE.toList schema) (NE.toList flds))
operation schema (AST.Core.Mutation flds)
= runCollectErrs (Schema.resolve (NE.toList schema) (NE.toList flds))