module Hasura.GraphQL.Execute.Mutation
  ( convertMutationSelectionSet
  ) where

import           Hasura.Prelude

import qualified Data.Environment                          as Env
import qualified Data.HashMap.Strict                       as Map
import qualified Data.HashMap.Strict.InsOrd                as OMap
import qualified Language.GraphQL.Draft.Syntax             as G
import qualified Network.HTTP.Client                       as HTTP
import qualified Network.HTTP.Types                        as HTTP

import qualified Hasura.GraphQL.Execute.RemoteJoin.Collect as RJ
import qualified Hasura.GraphQL.Transport.HTTP.Protocol    as GH
import qualified Hasura.Logging                            as L
import qualified Hasura.SQL.AnyBackend                     as AB
import qualified Hasura.Tracing                            as Tracing

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.Resolve
import           Hasura.GraphQL.Parser
import           Hasura.GraphQL.Parser.Directives
import           Hasura.Metadata.Class
import           Hasura.RQL.IR
import           Hasura.RQL.Types
import           Hasura.Server.Version                     (HasVersion)
import           Hasura.Session


convertMutationAction
  ::( HasVersion
    , MonadIO m
    , MonadError QErr m
    , MonadMetadataStorage (MetadataStorageT m)
    )
  => Env.Environment
  -> L.Logger L.Hasura
  -> UserInfo
  -> HTTP.Manager
  -> HTTP.RequestHeaders
  -> ActionMutation ('Postgres 'Vanilla) (Const Void) (UnpreparedValue ('Postgres 'Vanilla))
  -> m ActionExecutionPlan
convertMutationAction env logger userInfo manager reqHeaders  = \case
  AMSync s  -> pure $ AEPSync $ resolveActionExecution env logger userInfo s actionExecContext
  AMAsync s -> AEPAsyncMutation <$>
    liftEitherM (runMetadataStorageT $ resolveActionMutationAsync s reqHeaders userSession)
  where
    userSession = _uiSession userInfo
    actionExecContext = ActionExecContext manager reqHeaders $ _uiSession userInfo

convertMutationSelectionSet
  :: forall m
   . ( HasVersion
     , Tracing.MonadTrace m
     , MonadIO m
     , MonadError QErr m
     , MonadMetadataStorage (MetadataStorageT m)
     , MonadGQLExecutionCheck m
     )
  => Env.Environment
  -> L.Logger L.Hasura
  -> GQLContext
  -> SQLGenCtx
  -> UserInfo
  -> HTTP.Manager
  -> HTTP.RequestHeaders
  -> [G.Directive G.Name]
  -> G.SelectionSet G.NoFragments G.Name
  -> [G.VariableDefinition]
  -> Maybe GH.VariableValues
  -> SetGraphqlIntrospectionOptions
  -> m (ExecutionPlan, G.SelectionSet G.NoFragments Variable)
convertMutationSelectionSet env logger gqlContext SQLGenCtx{stringifyNum} userInfo manager reqHeaders directives fields varDefs varValsM introspectionDisabledRoles = do
  mutationParser <- onNothing (gqlMutationParser gqlContext) $
    throw400 ValidationFailed "no mutations exist"

  (resolvedDirectives, resolvedSelSet) <- resolveVariables varDefs (fromMaybe Map.empty varValsM) directives fields
  -- Parse the GraphQL query into the RQL AST
  (unpreparedQueries, _reusability)
    :: (OMap.InsOrdHashMap G.Name (MutationRootField UnpreparedValue), QueryReusability)
    <-(mutationParser >>> (`onLeft` reportParseErrors)) resolvedSelSet

  -- Process directives on the mutation
  (_dirMap, _) <-  (`onLeft` reportParseErrors) =<<
    runParseT (parseDirectives customDirectives (G.DLExecutable G.EDLMUTATION) resolvedDirectives)

  -- Transform the RQL AST into a prepared SQL query
  txs <- for unpreparedQueries \case
    RFDB sourceName exists ->
      AB.dispatchAnyBackend @BackendExecute exists
        \(SourceConfigWith (sourceConfig :: SourceConfig b) (MDBR db)) -> do
          let (noRelsDBAST, remoteJoins) = RJ.getRemoteJoinsMutationDB db
          dbStepInfo <- mkDBMutationPlan @b userInfo stringifyNum sourceName sourceConfig noRelsDBAST
          pure $ ExecStepDB [] (AB.mkAnyBackend dbStepInfo) remoteJoins
    RFRemote remoteField -> do
      RemoteFieldG remoteSchemaInfo resolvedRemoteField <- runVariableCache $ resolveRemoteField userInfo remoteField
      pure $ buildExecStepRemote remoteSchemaInfo G.OperationTypeMutation $ [G.SelectionField resolvedRemoteField]
    RFAction action -> do
      let (noRelsDBAST, remoteJoins) = RJ.getRemoteJoinsActionMutation action
      (actionName, _fch) <- pure $ case noRelsDBAST of
        AMSync s  -> (_aaeName s, _aaeForwardClientHeaders s)
        AMAsync s -> (_aamaName s, _aamaForwardClientHeaders s)
      plan <- convertMutationAction env logger userInfo manager reqHeaders noRelsDBAST
      pure $ ExecStepAction plan (ActionsInfo actionName _fch) remoteJoins -- `_fch` represents the `forward_client_headers` option from the action
                                                                -- definition which is currently being ignored for actions that are mutations
    RFRaw s -> flip onLeft throwError =<< executeIntrospection userInfo s introspectionDisabledRoles
  return (txs, resolvedSelSet)