graphql-engine/server/src-lib/Hasura/GraphQL/Transport/HTTP.hs

-- | Execution of GraphQL queries over HTTP transport
module Hasura.GraphQL.Transport.HTTP
  ( QueryCacheKey (..),
    MonadExecuteQuery (..),
    CachedDirective (..),
    runGQ,
    runGQBatched,
    coalescePostgresMutations,
    extractFieldFromResponse,
    buildRaw,
    encodeAnnotatedResponseParts,
    encodeEncJSONResults,

    -- * imported from HTTP.Protocol; required by pro
    GQLReq (..),
    GQLReqUnparsed,
    GQLReqParsed,
    GQLExecDoc (..),
    OperationName (..),
    GQLQueryText (..),
    AnnotatedResponsePart (..),
    CacheStoreSuccess (..),
    CacheStoreFailure (..),
    SessVarPred,
    filterVariablesFromQuery,
    runSessVarPred,
  )
where

import Control.Lens (Traversal', toListOf)
import Control.Monad.Morph (hoist)
import Control.Monad.Trans.Control (MonadBaseControl)
import Data.Aeson qualified as J
import Data.Aeson.Ordered qualified as JO
import Data.ByteString.Lazy qualified as LBS
import Data.Dependent.Map qualified as DM
import Data.Environment qualified as Env
import Data.HashMap.Strict.InsOrd qualified as OMap
import Data.Text qualified as T
import Hasura.Backends.Postgres.Instances.Transport (runPGMutationTransaction)
import Hasura.Base.Error
import Hasura.EncJSON
import Hasura.GraphQL.Execute qualified as E
import Hasura.GraphQL.Execute.Action qualified as EA
import Hasura.GraphQL.Execute.Backend qualified as EB
import Hasura.GraphQL.Execute.RemoteJoin qualified as RJ
import Hasura.GraphQL.Logging
  ( MonadQueryLog (logQueryLog),
    QueryLog (..),
    QueryLogKind (..),
  )
import Hasura.GraphQL.Namespace
import Hasura.GraphQL.ParameterizedQueryHash
import Hasura.GraphQL.Parser.Column (UnpreparedValue (..))
import Hasura.GraphQL.Parser.Directives (CachedDirective (..), DirectiveMap, cached)
import Hasura.GraphQL.Transport.Backend
import Hasura.GraphQL.Transport.HTTP.Protocol
import Hasura.GraphQL.Transport.Instances ()
import Hasura.HTTP
import Hasura.Logging qualified as L
import Hasura.Metadata.Class
import Hasura.Prelude
import Hasura.RQL.IR
import Hasura.RQL.Types
import Hasura.SQL.AnyBackend qualified as AB
import Hasura.Server.Init.Config
import Hasura.Server.Limits
import Hasura.Server.Logging
import Hasura.Server.Logging qualified as L
import Hasura.Server.Telemetry.Counters qualified as Telem
import Hasura.Server.Types (RequestId)
import Hasura.Session
import Hasura.Tracing (MonadTrace, TraceT, trace)
import Hasura.Tracing qualified as Tracing
import Language.GraphQL.Draft.Syntax qualified as G
import Network.HTTP.Client qualified as HTTP
import Network.HTTP.Types qualified as HTTP
import Network.Wai.Extended qualified as Wai

data QueryCacheKey = QueryCacheKey
  { qckQueryString :: !GQLReqParsed,
    qckUserRole :: !RoleName,
    qckSession :: !SessionVariables
  }

instance J.ToJSON QueryCacheKey where
  toJSON (QueryCacheKey qs ur sess) =
    J.object ["query_string" J..= qs, "user_role" J..= ur, "session" J..= sess]

type CacheStoreResponse = Either CacheStoreFailure CacheStoreSuccess

data CacheStoreSuccess
  = CacheStoreSkipped
  | CacheStoreHit
  deriving (Eq, Show)

data CacheStoreFailure
  = CacheStoreLimitReached
  | CacheStoreNotEnoughCapacity
  | CacheStoreBackendError String
  deriving (Eq, Show)

class Monad m => MonadExecuteQuery m where
  -- | This method does two things: it looks up a query result in the
  -- server-side cache, if a cache is used, and it additionally returns HTTP
  -- headers that can instruct a client how long a response can be cached
  -- locally (i.e. client-side).
  cacheLookup ::
    -- | Used to check if the elaborated query supports caching
    [RemoteSchemaInfo] ->
    -- | Used to check if actions query supports caching (unsupported if `forward_client_headers` is set)
    [ActionsInfo] ->
    -- | Key that uniquely identifies the result of a query execution
    QueryCacheKey ->
    -- | Cached Directive from GraphQL query AST
    Maybe CachedDirective ->
    -- | HTTP headers to be sent back to the caller for this GraphQL request,
    -- containing e.g. time-to-live information, and a cached value if found and
    -- within time-to-live.  So a return value (non-empty-ttl-headers, Nothing)
    -- represents that we don't have a server-side cache of the query, but that
    -- the client should store it locally.  The value ([], Just json) represents
    -- that the client should not store the response locally, but we do have a
    -- server-side cache value that can be used to avoid query execution.
    TraceT (ExceptT QErr m) (HTTP.ResponseHeaders, Maybe EncJSON)

  -- | Store a json response for a query that we've executed in the cache.  Note
  -- that, as part of this, 'cacheStore' has to decide whether the response is
  -- cacheable.  A very similar decision is also made in 'cacheLookup', since it
  -- has to construct corresponding cache-enabling headers that are sent to the
  -- client.  But note that the HTTP headers influence client-side caching,
  -- whereas 'cacheStore' changes the server-side cache.
  cacheStore ::
    -- | Key under which to store the result of a query execution
    QueryCacheKey ->
    -- | Cached Directive from GraphQL query AST
    Maybe CachedDirective ->
    -- | Result of a query execution
    EncJSON ->
    -- | Always succeeds
    TraceT (ExceptT QErr m) CacheStoreResponse

  default cacheLookup ::
    (m ~ t n, MonadTrans t, MonadExecuteQuery n) =>
    [RemoteSchemaInfo] ->
    [ActionsInfo] ->
    QueryCacheKey ->
    Maybe CachedDirective ->
    TraceT (ExceptT QErr m) (HTTP.ResponseHeaders, Maybe EncJSON)
  cacheLookup a b c d = hoist (hoist lift) $ cacheLookup a b c d

  default cacheStore ::
    (m ~ t n, MonadTrans t, MonadExecuteQuery n) =>
    QueryCacheKey ->
    Maybe CachedDirective ->
    EncJSON ->
    TraceT (ExceptT QErr m) CacheStoreResponse
  cacheStore a b c = hoist (hoist lift) $ cacheStore a b c

instance MonadExecuteQuery m => MonadExecuteQuery (ReaderT r m)

instance MonadExecuteQuery m => MonadExecuteQuery (ExceptT r m)

instance MonadExecuteQuery m => MonadExecuteQuery (TraceT m)

instance MonadExecuteQuery m => MonadExecuteQuery (MetadataStorageT m)

-- | A partial response, e.g. from a remote schema call or postgres
-- postgres query, which we'll assemble into the final response for
-- the client. It is annotated with timing metadata.
data AnnotatedResponsePart = AnnotatedResponsePart
  { arpTimeIO :: DiffTime,
    arpLocality :: Telem.Locality,
    arpResponse :: EncJSON,
    arpHeaders :: HTTP.ResponseHeaders
  }

-- | A full response, annotated with timing metadata.
data AnnotatedResponse = AnnotatedResponse
  { arQueryType :: Telem.QueryType,
    arTimeIO :: DiffTime,
    arLocality :: Telem.Locality,
    arResponse :: HttpResponse (Maybe GQResponse, EncJSON)
  }

-- | Merge response parts into a full response.
buildResponseFromParts ::
  (MonadError QErr m) =>
  Telem.QueryType ->
  Either (Either GQExecError QErr) (RootFieldMap AnnotatedResponsePart) ->
  HTTP.ResponseHeaders ->
  m AnnotatedResponse
buildResponseFromParts telemType partsErr cacheHeaders =
  buildResponse telemType partsErr \parts ->
    let responseData = Right $ encJToLBS $ encodeAnnotatedResponseParts parts
     in AnnotatedResponse
          { arQueryType = telemType,
            arTimeIO = sum (fmap arpTimeIO parts),
            arLocality = foldMap arpLocality parts,
            arResponse =
              HttpResponse
                (Just responseData, encodeGQResp responseData)
                (cacheHeaders <> foldMap arpHeaders parts)
          }

buildResponse ::
  (MonadError QErr m) =>
  Telem.QueryType ->
  Either (Either GQExecError QErr) a ->
  (a -> AnnotatedResponse) ->
  m AnnotatedResponse
buildResponse telemType res f = case res of
  Right a -> pure $ f a
  Left (Right err) -> throwError err
  Left (Left err) ->
    pure $
      AnnotatedResponse
        { arQueryType = telemType,
          arTimeIO = 0,
          arLocality = Telem.Remote,
          arResponse =
            HttpResponse
              (Just (Left err), encodeGQResp $ Left err)
              []
        }

-- | A predicate on session variables. The 'Monoid' instance makes it simple
-- to combine several predicates disjunctively.
newtype SessVarPred = SessVarPred {unSessVarPred :: SessionVariable -> SessionVariableValue -> Bool}

keepAllSessionVariables :: SessVarPred
keepAllSessionVariables = SessVarPred $ \_ _ -> True

instance Semigroup SessVarPred where
  SessVarPred p1 <> SessVarPred p2 = SessVarPred $ \sv svv ->
    p1 sv svv || p2 sv svv

instance Monoid SessVarPred where
  mempty = SessVarPred $ \_ _ -> False

runSessVarPred :: SessVarPred -> SessionVariables -> SessionVariables
runSessVarPred = filterSessionVariables . unSessVarPred

-- | Filter out only those session variables used by the query AST provided
filterVariablesFromQuery ::
  Backend backend =>
  [RootField (QueryDBRoot (RemoteSelect UnpreparedValue) UnpreparedValue) RemoteField (ActionQuery backend (RemoteSelect UnpreparedValue) (UnpreparedValue backend)) d] ->
  SessVarPred
filterVariablesFromQuery query = fold $ rootToSessVarPreds =<< query
  where
    rootToSessVarPreds = \case
      RFDB _ exists ->
        AB.dispatchAnyBackend @Backend exists \case
          SourceConfigWith _ _ (QDBR db) -> toPred <$> toListOf traverse db
      RFRemote remote -> match <$> toListOf (traverse . _SessionPresetVariable) remote
      RFAction actionQ -> toPred <$> toListOf traverse actionQ
      _ -> []

    _SessionPresetVariable :: Traversal' RemoteSchemaVariable SessionVariable
    _SessionPresetVariable f (SessionPresetVariable a b c) =
      (\a' -> SessionPresetVariable a' b c) <$> f a
    _SessionPresetVariable _ x = pure x

    toPred :: UnpreparedValue bet -> SessVarPred
    -- if we see a reference to the whole session variables object,
    -- then we need to keep everything:
    toPred UVSession = keepAllSessionVariables
    -- if we only see a specific session variable, we only need to keep that one:
    toPred (UVSessionVar _type sv) = match sv
    toPred _ = mempty

    match :: SessionVariable -> SessVarPred
    match sv = SessVarPred $ \sv' _ -> sv == sv'

-- | Run (execute) a single GraphQL query
runGQ ::
  forall m.
  ( MonadIO m,
    MonadBaseControl IO m,
    MonadError QErr m,
    MonadReader E.ExecutionCtx m,
    E.MonadGQLExecutionCheck m,
    MonadQueryLog m,
    MonadTrace m,
    MonadExecuteQuery m,
    MonadMetadataStorage (MetadataStorageT m),
    EB.MonadQueryTags m,
    HasResourceLimits m
  ) =>
  Env.Environment ->
  L.Logger L.Hasura ->
  RequestId ->
  UserInfo ->
  Wai.IpAddress ->
  [HTTP.Header] ->
  E.GraphQLQueryType ->
  GQLReqUnparsed ->
  m (GQLQueryOperationSuccessLog, HttpResponse (Maybe GQResponse, EncJSON))
runGQ env logger reqId userInfo ipAddress reqHeaders queryType reqUnparsed = do
  (totalTime, (response, parameterizedQueryHash)) <- withElapsedTime $ do
    E.ExecutionCtx _ sqlGenCtx sc scVer httpManager enableAL <- ask

    -- run system authorization on the GraphQL API
    reqParsed <-
      E.checkGQLExecution userInfo (reqHeaders, ipAddress) enableAL sc reqUnparsed
        >>= flip onLeft throwError

    operationLimit <- askGraphqlOperationLimit
    let runLimits = runResourceLimits $ operationLimit userInfo (scApiLimits sc)

    (parameterizedQueryHash, execPlan) <-
      E.getResolvedExecPlan
        env
        logger
        userInfo
        sqlGenCtx
        sc
        scVer
        queryType
        httpManager
        reqHeaders
        (reqUnparsed, reqParsed)
        reqId

    response <- executePlan httpManager reqParsed runLimits execPlan
    return (response, parameterizedQueryHash)

  recordTimings totalTime response
  let requestSize = LBS.length $ J.encode reqUnparsed
      responseSize = LBS.length $ encJToLBS $ snd $ _hrBody $ arResponse $ response
  return
    ( GQLQueryOperationSuccessLog reqUnparsed totalTime responseSize requestSize parameterizedQueryHash,
      arResponse response
    )
  where
    doQErr :: ExceptT QErr m a -> ExceptT (Either GQExecError QErr) m a
    doQErr = withExceptT Right

    forWithKey = flip OMap.traverseWithKey

    executePlan ::
      HTTP.Manager ->
      GQLReqParsed ->
      (m AnnotatedResponse -> m AnnotatedResponse) ->
      E.ResolvedExecutionPlan ->
      m AnnotatedResponse
    executePlan httpManager reqParsed runLimits execPlan = case execPlan of
      E.QueryExecutionPlan queryPlans asts dirMap -> trace "Query" $ do
        let (keyedLookup, keyedStore) = cacheAccess reqParsed queryPlans asts dirMap
        (cachingHeaders, cachedValue) <- keyedLookup
        case fmap decodeGQResp cachedValue of
          Just cachedResponseData -> do
            logQueryLog logger $ QueryLog reqUnparsed Nothing reqId QueryLogKindCached
            pure $
              AnnotatedResponse
                { arQueryType = Telem.Query,
                  arTimeIO = 0,
                  arLocality = Telem.Local,
                  arResponse = HttpResponse cachedResponseData cachingHeaders
                }
          Nothing -> runLimits $ do
            conclusion <- runExceptT $ forWithKey queryPlans $ executeQueryStep httpManager
            result <- buildResponseFromParts Telem.Query conclusion cachingHeaders
            let response@(HttpResponse responseData _) = arResponse result
            cacheStoreRes <- keyedStore (snd responseData)
            let headers = case cacheStoreRes of
                  -- Note: Warning header format: "Warning: <warn-code> <warn-agent> <warn-text> [warn-date]"
                  -- See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Warning
                  Right _ -> []
                  (Left CacheStoreLimitReached) -> [("warning", "199 - cache-store-size-limit-exceeded")]
                  (Left CacheStoreNotEnoughCapacity) -> [("warning", "199 - cache-store-capacity-exceeded")]
                  (Left (CacheStoreBackendError _)) -> [("warning", "199 - cache-store-error")]
             in pure $ result {arResponse = addHttpResponseHeaders headers response}
      E.MutationExecutionPlan mutationPlans -> runLimits $ do
        {- Note [Backwards-compatible transaction optimisation]

           For backwards compatibility, we perform the following optimisation: if all mutation steps
           are going to the same source, and that source is Postgres, we group all mutations as a
           transaction. This is a somewhat dangerous beaviour, and we would prefer, in the future,
           to make transactionality explicit rather than implicit and context-dependent.
        -}
        case coalescePostgresMutations mutationPlans of
          -- we are in the aforementioned case; we circumvent the normal process
          Just (sourceConfig, pgMutations) -> do
            res <-
              runExceptT $
                doQErr $
                  runPGMutationTransaction reqId reqUnparsed userInfo logger sourceConfig pgMutations
            -- we do not construct response parts since we have only one part
            buildResponse Telem.Mutation res \(telemTimeIO_DT, parts) ->
              let responseData = Right $ encJToLBS $ encodeEncJSONResults parts
               in AnnotatedResponse
                    { arQueryType = Telem.Mutation,
                      arTimeIO = telemTimeIO_DT,
                      arLocality = Telem.Local,
                      arResponse =
                        HttpResponse
                          (Just responseData, encodeGQResp responseData)
                          []
                    }

          -- we are not in the transaction case; proceeding normally
          Nothing -> do
            conclusion <- runExceptT $ forWithKey mutationPlans $ executeMutationStep httpManager
            buildResponseFromParts Telem.Mutation conclusion []
      E.SubscriptionExecutionPlan _sub ->
        throw400 UnexpectedPayload "subscriptions are not supported over HTTP, use websockets instead"

    executeQueryStep ::
      HTTP.Manager ->
      RootFieldAlias ->
      EB.ExecutionStep ->
      ExceptT (Either GQExecError QErr) m AnnotatedResponsePart
    executeQueryStep httpManager fieldName = \case
      E.ExecStepDB _headers exists remoteJoins -> doQErr $ do
        (telemTimeIO_DT, resp) <-
          AB.dispatchAnyBackend @BackendTransport
            exists
            \(EB.DBStepInfo _ sourceConfig genSql tx :: EB.DBStepInfo b) ->
              runDBQuery @b reqId reqUnparsed fieldName userInfo logger sourceConfig tx genSql
        finalResponse <-
          RJ.processRemoteJoins reqId logger env httpManager reqHeaders userInfo resp remoteJoins reqUnparsed
        pure $ AnnotatedResponsePart telemTimeIO_DT Telem.Local finalResponse []
      E.ExecStepRemote rsi resultCustomizer gqlReq -> do
        logQueryLog logger $ QueryLog reqUnparsed Nothing reqId QueryLogKindRemoteSchema
        runRemoteGQ httpManager fieldName rsi resultCustomizer gqlReq
      E.ExecStepAction aep _ remoteJoins -> do
        logQueryLog logger $ QueryLog reqUnparsed Nothing reqId QueryLogKindAction
        (time, resp) <- doQErr $ do
          (time, (resp, _)) <- EA.runActionExecution userInfo aep
          finalResponse <-
            RJ.processRemoteJoins reqId logger env httpManager reqHeaders userInfo resp remoteJoins reqUnparsed
          pure (time, finalResponse)
        pure $ AnnotatedResponsePart time Telem.Empty resp []
      E.ExecStepRaw json -> do
        logQueryLog logger $ QueryLog reqUnparsed Nothing reqId QueryLogKindIntrospection
        buildRaw json

    executeMutationStep ::
      HTTP.Manager ->
      RootFieldAlias ->
      EB.ExecutionStep ->
      ExceptT (Either GQExecError QErr) m AnnotatedResponsePart
    executeMutationStep httpManager fieldName = \case
      E.ExecStepDB responseHeaders exists remoteJoins -> doQErr $ do
        (telemTimeIO_DT, resp) <-
          AB.dispatchAnyBackend @BackendTransport
            exists
            \(EB.DBStepInfo _ sourceConfig genSql tx :: EB.DBStepInfo b) ->
              runDBMutation @b reqId reqUnparsed fieldName userInfo logger sourceConfig tx genSql
        finalResponse <-
          RJ.processRemoteJoins reqId logger env httpManager reqHeaders userInfo resp remoteJoins reqUnparsed
        pure $ AnnotatedResponsePart telemTimeIO_DT Telem.Local finalResponse responseHeaders
      E.ExecStepRemote rsi resultCustomizer gqlReq -> do
        logQueryLog logger $ QueryLog reqUnparsed Nothing reqId QueryLogKindRemoteSchema
        runRemoteGQ httpManager fieldName rsi resultCustomizer gqlReq
      E.ExecStepAction aep _ remoteJoins -> do
        logQueryLog logger $ QueryLog reqUnparsed Nothing reqId QueryLogKindAction
        (time, (resp, hdrs)) <- doQErr $ do
          (time, (resp, hdrs)) <- EA.runActionExecution userInfo aep
          finalResponse <-
            RJ.processRemoteJoins reqId logger env httpManager reqHeaders userInfo resp remoteJoins reqUnparsed
          pure (time, (finalResponse, hdrs))
        pure $ AnnotatedResponsePart time Telem.Empty resp $ fromMaybe [] hdrs
      E.ExecStepRaw json -> do
        logQueryLog logger $ QueryLog reqUnparsed Nothing reqId QueryLogKindIntrospection
        buildRaw json

    runRemoteGQ httpManager fieldName rsi resultCustomizer gqlReq = do
      (telemTimeIO_DT, remoteResponseHeaders, resp) <-
        doQErr $ E.execRemoteGQ env httpManager userInfo reqHeaders (rsDef rsi) gqlReq
      value <- extractFieldFromResponse fieldName rsi resultCustomizer resp
      let filteredHeaders = filter ((== "Set-Cookie") . fst) remoteResponseHeaders
      pure $ AnnotatedResponsePart telemTimeIO_DT Telem.Remote (encJFromOrderedValue value) filteredHeaders

    cacheAccess ::
      GQLReqParsed ->
      EB.ExecutionPlan ->
      [QueryRootField UnpreparedValue] ->
      DirectiveMap ->
      ( m (HTTP.ResponseHeaders, Maybe EncJSON),
        EncJSON -> m CacheStoreResponse
      )
    cacheAccess reqParsed queryPlans asts dirMap =
      let filteredSessionVars = runSessVarPred (filterVariablesFromQuery asts) (_uiSession userInfo)
          remoteSchemas =
            OMap.elems queryPlans >>= \case
              E.ExecStepDB _headers _dbAST remoteJoins -> do
                maybe [] (map RJ._rsjRemoteSchema . RJ.getRemoteSchemaJoins) remoteJoins
              _ -> []
          getExecStepActionWithActionInfo acc execStep = case execStep of
            EB.ExecStepAction _ actionInfo _remoteJoins -> (actionInfo : acc)
            _ -> acc
          actionsInfo =
            foldl getExecStepActionWithActionInfo [] $
              OMap.elems $
                OMap.filter
                  ( \case
                      E.ExecStepAction _ _ _remoteJoins -> True
                      _ -> False
                  )
                  queryPlans
          cacheKey = QueryCacheKey reqParsed (_uiRole userInfo) filteredSessionVars
          cachedDirective = runIdentity <$> DM.lookup cached dirMap
       in ( Tracing.interpTraceT (liftEitherM . runExceptT) $
              cacheLookup remoteSchemas actionsInfo cacheKey cachedDirective,
            Tracing.interpTraceT (liftEitherM . runExceptT)
              . cacheStore cacheKey cachedDirective
          )

    recordTimings :: DiffTime -> AnnotatedResponse -> m ()
    recordTimings totalTime result = do
      Telem.recordTimingMetric
        Telem.RequestDimensions
          { telemTransport = Telem.HTTP,
            telemQueryType = arQueryType result,
            telemLocality = arLocality result
          }
        Telem.RequestTimings
          { telemTimeIO = convertDuration $ arTimeIO result,
            telemTimeTot = convertDuration totalTime
          }

coalescePostgresMutations ::
  EB.ExecutionPlan ->
  Maybe
    ( SourceConfig ('Postgres 'Vanilla),
      InsOrdHashMap RootFieldAlias (EB.DBStepInfo ('Postgres 'Vanilla))
    )
coalescePostgresMutations plan = do
  -- we extract the name and config of the first mutation root, if any
  (oneSourceName, oneSourceConfig) <- case toList plan of
    (E.ExecStepDB _ exists _remoteJoins : _) ->
      AB.unpackAnyBackend @('Postgres 'Vanilla) exists <&> \dbsi ->
        ( EB.dbsiSourceName dbsi,
          EB.dbsiSourceConfig dbsi
        )
    _ -> Nothing
  -- we then test whether all mutations are going to that same first source
  -- and that it is Postgres
  mutations <- for plan \case
    E.ExecStepDB _ exists remoteJoins -> do
      dbStepInfo <- AB.unpackAnyBackend @('Postgres 'Vanilla) exists
      guard $ oneSourceName == EB.dbsiSourceName dbStepInfo && isNothing remoteJoins
      Just dbStepInfo
    _ -> Nothing
  Just (oneSourceConfig, mutations)

data GraphQLResponse
  = GraphQLResponseErrors [J.Value]
  | GraphQLResponseData JO.Value

decodeGraphQLResponse :: LBS.ByteString -> Either Text GraphQLResponse
decodeGraphQLResponse bs = do
  val <- mapLeft T.pack $ JO.eitherDecode bs
  valObj <- JO.asObject val
  case JO.lookup "errors" valObj of
    Just (JO.Array errs) -> Right $ GraphQLResponseErrors (toList $ JO.fromOrdered <$> errs)
    Just _ -> Left "Invalid \"errors\" field in response from remote"
    Nothing -> do
      dataVal <- JO.lookup "data" valObj `onNothing` Left "Missing \"data\" field in response from remote"
      Right $ GraphQLResponseData dataVal

extractFieldFromResponse ::
  forall m.
  Monad m =>
  RootFieldAlias ->
  RemoteSchemaInfo ->
  ResultCustomizer ->
  LBS.ByteString ->
  ExceptT (Either GQExecError QErr) m JO.Value
extractFieldFromResponse fieldName rsi resultCustomizer resp = do
  let namespace = fmap G.unName $ _rscNamespaceFieldName $ rsCustomizer rsi
      fieldName' = G.unName $ _rfaAlias fieldName
  -- TODO: use RootFieldAlias for remote fields
  dataVal <-
    applyResultCustomizer resultCustomizer
      <$> do
        graphQLResponse <- decodeGraphQLResponse resp `onLeft` do400
        case graphQLResponse of
          GraphQLResponseErrors errs -> doGQExecError errs
          GraphQLResponseData d -> pure d
  case namespace of
    Just _ ->
      -- If using a custom namespace field then the response from the remote server
      -- will already be unwrapped so just return it.
      return dataVal
    _ -> do
      -- No custom namespace so we need to look up the field name in the data
      -- object.
      dataObj <- onLeft (JO.asObject dataVal) do400
      fieldVal <-
        onNothing (JO.lookup fieldName' dataObj) $
          do400 $ "expecting key " <> fieldName'
      return fieldVal
  where
    do400 = withExceptT Right . throw400 RemoteSchemaError
    doGQExecError = withExceptT Left . throwError . GQExecError

buildRaw :: Applicative m => JO.Value -> m AnnotatedResponsePart
buildRaw json = do
  let obj = encJFromOrderedValue json
      telemTimeIO_DT = 0
  pure $ AnnotatedResponsePart telemTimeIO_DT Telem.Local obj []

encodeAnnotatedResponseParts :: RootFieldMap AnnotatedResponsePart -> EncJSON
encodeAnnotatedResponseParts = encodeEncJSONResults . fmap arpResponse

encodeEncJSONResults :: RootFieldMap EncJSON -> EncJSON
encodeEncJSONResults =
  encNameMap . fmap (namespacedField id encNameMap) . unflattenNamespaces
  where
    encNameMap = encJFromInsOrdHashMap . OMap.mapKeys G.unName

-- | Run (execute) a batched GraphQL query (see 'GQLBatchedReqs').
runGQBatched ::
  forall m.
  ( MonadIO m,
    MonadBaseControl IO m,
    MonadError QErr m,
    MonadReader E.ExecutionCtx m,
    E.MonadGQLExecutionCheck m,
    MonadQueryLog m,
    MonadTrace m,
    MonadExecuteQuery m,
    HttpLog m,
    MonadMetadataStorage (MetadataStorageT m),
    EB.MonadQueryTags m,
    HasResourceLimits m
  ) =>
  Env.Environment ->
  L.Logger L.Hasura ->
  RequestId ->
  ResponseInternalErrorsConfig ->
  UserInfo ->
  Wai.IpAddress ->
  [HTTP.Header] ->
  E.GraphQLQueryType ->
  -- | the batched request with unparsed GraphQL query
  GQLBatchedReqs (GQLReq GQLQueryText) ->
  m (HttpLogMetadata m, HttpResponse EncJSON)
runGQBatched env logger reqId responseErrorsConfig userInfo ipAddress reqHdrs queryType query =
  case query of
    GQLSingleRequest req -> do
      (gqlQueryOperationLog, httpResp) <- runGQ env logger reqId userInfo ipAddress reqHdrs queryType req
      let httpLoggingMetadata = buildHttpLogMetadata @m (PQHSetSingleton (gqolParameterizedQueryHash gqlQueryOperationLog)) L.RequestModeSingle (Just (GQLSingleRequest (GQLQueryOperationSuccess gqlQueryOperationLog)))
      pure (httpLoggingMetadata, snd <$> httpResp)
    GQLBatchedReqs reqs -> do
      -- It's unclear what we should do if we receive multiple
      -- responses with distinct headers, so just do the simplest thing
      -- in this case, and don't forward any.
      let includeInternal = shouldIncludeInternal (_uiRole userInfo) responseErrorsConfig
          removeHeaders =
            flip HttpResponse []
              . encJFromList
              . map (either (encJFromJValue . encodeGQErr includeInternal) _hrBody)
      responses <- traverse (\req -> fmap (req,) . try . (fmap . fmap . fmap) snd . runGQ env logger reqId userInfo ipAddress reqHdrs queryType $ req) reqs
      let requestsOperationLogs = map fst $ rights $ map snd responses
          batchOperationLogs =
            map
              ( \(req, resp) ->
                  case resp of
                    Left err -> GQLQueryOperationError $ GQLQueryOperationErrorLog req err
                    Right (successOpLog, _) -> GQLQueryOperationSuccess successOpLog
              )
              responses
          parameterizedQueryHashes = map gqolParameterizedQueryHash requestsOperationLogs
          httpLoggingMetadata = buildHttpLogMetadata @m (PQHSetBatched parameterizedQueryHashes) L.RequestModeBatched (Just (GQLBatchedReqs batchOperationLogs))
      pure (httpLoggingMetadata, removeHeaders (map ((fmap snd) . snd) responses))
  where
    try = flip catchError (pure . Left) . fmap Right