module Hasura.GraphQL.Execute.Query
  ( convertQuerySelSet,
    parseGraphQLQuery,
  )
where

import Data.Aeson qualified as J
import Data.Environment qualified as Env
import Data.HashMap.Strict qualified as Map
import Data.HashMap.Strict.InsOrd qualified as OMap
import Data.Tagged qualified as Tagged
import Hasura.Base.Error
import Hasura.GraphQL.Context
import Hasura.GraphQL.Execute.Action
import Hasura.GraphQL.Execute.Backend
import Hasura.GraphQL.Execute.Common
import Hasura.GraphQL.Execute.Instances ()
import Hasura.GraphQL.Execute.Remote
import Hasura.GraphQL.Execute.RemoteJoin.Collect qualified as RJ
import Hasura.GraphQL.Execute.Resolve
import Hasura.GraphQL.Namespace
import Hasura.GraphQL.ParameterizedQueryHash
import Hasura.GraphQL.Parser.Directives
import Hasura.GraphQL.Schema.Parser
import Hasura.GraphQL.Transport.HTTP.Protocol qualified as GH
import Hasura.Logging qualified as L
import Hasura.Prelude
import Hasura.QueryTags
import Hasura.RQL.IR
import Hasura.RQL.Types.Action
import Hasura.RQL.Types.Backend
import Hasura.RQL.Types.GraphqlSchemaIntrospection
import Hasura.RQL.Types.QueryTags
import Hasura.SQL.AnyBackend qualified as AB
import Hasura.Server.Prometheus (PrometheusMetrics (..))
import Hasura.Server.Types (RequestId (..))
import Hasura.Services.Network
import Hasura.Session
import Language.GraphQL.Draft.Syntax qualified as G
import Network.HTTP.Types qualified as HTTP

parseGraphQLQuery ::
  MonadError QErr m =>
  GQLContext ->
  [G.VariableDefinition] ->
  Maybe (HashMap G.Name J.Value) ->
  [G.Directive G.Name] ->
  G.SelectionSet G.NoFragments G.Name ->
  m
    ( RootFieldMap (QueryRootField UnpreparedValue),
      [G.Directive Variable],
      G.SelectionSet G.NoFragments Variable
    )
parseGraphQLQuery gqlContext varDefs varValsM directives fields = do
  (resolvedDirectives, resolvedSelSet) <- resolveVariables varDefs (fromMaybe Map.empty varValsM) directives fields
  parsedQuery <- liftEither $ gqlQueryParser gqlContext resolvedSelSet
  pure (parsedQuery, resolvedDirectives, resolvedSelSet)

-- | Construct an 'ExecutionPlan' from a 'G.SelectionSet'.
convertQuerySelSet ::
  forall m.
  ( MonadError QErr m,
    MonadGQLExecutionCheck m,
    MonadQueryTags m,
    ProvidesNetwork m
  ) =>
  Env.Environment ->
  L.Logger L.Hasura ->
  PrometheusMetrics ->
  GQLContext ->
  UserInfo ->
  HTTP.RequestHeaders ->
  [G.Directive G.Name] ->
  G.SelectionSet G.NoFragments G.Name ->
  [G.VariableDefinition] ->
  GH.GQLReqUnparsed ->
  SetGraphqlIntrospectionOptions ->
  RequestId ->
  -- | Graphql Operation Name
  Maybe G.Name ->
  m (ExecutionPlan, [QueryRootField UnpreparedValue], DirectiveMap, ParameterizedQueryHash)
convertQuerySelSet
  env
  logger
  prometheusMetrics
  gqlContext
  userInfo
  reqHeaders
  directives
  fields
  varDefs
  gqlUnparsed
  introspectionDisabledRoles
  reqId
  maybeOperationName = do
    -- 1. Parse the GraphQL query into the 'RootFieldMap' and a 'SelectionSet'
    (unpreparedQueries, normalizedDirectives, normalizedSelectionSet) <-
      parseGraphQLQuery gqlContext varDefs (GH._grVariables gqlUnparsed) directives fields

    -- 2. Parse directives on the query
    dirMap <- toQErr $ runParse (parseDirectives customDirectives (G.DLExecutable G.EDLQUERY) normalizedDirectives)

    let parameterizedQueryHash = calculateParameterizedQueryHash normalizedSelectionSet

        resolveExecutionSteps rootFieldName rootFieldUnpreparedValue = do
          case rootFieldUnpreparedValue of
            RFMulti lst -> do
              allSteps <- traverse (resolveExecutionSteps rootFieldName) lst
              pure $ ExecStepMulti allSteps
            RFDB sourceName exists ->
              AB.dispatchAnyBackend @BackendExecute
                exists
                \(SourceConfigWith (sourceConfig :: (SourceConfig b)) queryTagsConfig (QDBR db)) -> do
                  let mReqId =
                        case _qtcOmitRequestId <$> queryTagsConfig of
                          -- we include the request id only if a user explicitly wishes for it to be included.
                          Just False -> Just reqId
                          _ -> Nothing
                      queryTagsAttributes = encodeQueryTags $ QTQuery $ QueryMetadata mReqId maybeOperationName rootFieldName parameterizedQueryHash
                      queryTagsComment = Tagged.untag $ createQueryTags @m queryTagsAttributes queryTagsConfig
                      (noRelsDBAST, remoteJoins) = RJ.getRemoteJoinsQueryDB db
                  dbStepInfo <- flip runReaderT queryTagsComment $ mkDBQueryPlan @b userInfo env sourceName sourceConfig noRelsDBAST reqHeaders maybeOperationName
                  pure $ ExecStepDB [] (AB.mkAnyBackend dbStepInfo) remoteJoins
            RFRemote rf -> do
              RemoteSchemaRootField remoteSchemaInfo resultCustomizer remoteField <- runVariableCache $ for rf $ resolveRemoteVariable userInfo
              let (noRelsRemoteField, remoteJoins) = RJ.getRemoteJoinsGraphQLField remoteField
              pure $ buildExecStepRemote remoteSchemaInfo resultCustomizer G.OperationTypeQuery noRelsRemoteField remoteJoins (GH._grOperationName gqlUnparsed)
            RFAction action -> do
              httpManager <- askHTTPManager
              let (noRelsDBAST, remoteJoins) = RJ.getRemoteJoinsActionQuery action
              (actionExecution, actionName, fch) <- pure $ case noRelsDBAST of
                AQQuery s ->
                  ( AEPSync $
                      resolveActionExecution
                        httpManager
                        env
                        logger
                        prometheusMetrics
                        s
                        (ActionExecContext reqHeaders (_uiSession userInfo))
                        (Just (GH._grQuery gqlUnparsed)),
                    _aaeName s,
                    _aaeForwardClientHeaders s
                  )
                AQAsync s -> (AEPAsyncQuery $ AsyncActionQueryExecutionPlan (_aaaqActionId s) $ resolveAsyncActionQuery userInfo s, _aaaqName s, _aaaqForwardClientHeaders s)
              pure $ ExecStepAction actionExecution (ActionsInfo actionName fch) remoteJoins
            RFRaw r -> flip onLeft throwError =<< executeIntrospection userInfo r introspectionDisabledRoles
    -- 3. Transform the 'RootFieldMap' into an execution plan
    executionPlan <- flip OMap.traverseWithKey unpreparedQueries $ resolveExecutionSteps
    pure (executionPlan, OMap.elems unpreparedQueries, dirMap, parameterizedQueryHash)