{-# OPTIONS_GHC -fno-warn-orphans #-}


module Hasura.Backends.MySQL.Instances.Transport (runQuery) where

import           Hasura.Prelude

import qualified Data.Aeson                              as J
import           Data.Text.Extended
import           Hasura.Backends.MySQL.Instances.Execute ()
import           Hasura.Base.Error
import           Hasura.EncJSON
import           Hasura.GraphQL.Execute.Backend          (PreparedQuery)
import           Hasura.GraphQL.Logging
import           Hasura.GraphQL.Transport.Backend
import           Hasura.GraphQL.Transport.HTTP.Protocol
import qualified Hasura.Logging                          as L
import           Hasura.RQL.Types
import           Hasura.Server.Types                     (RequestId)
import           Hasura.Session
import           Hasura.Tracing
import qualified Language.GraphQL.Draft.Syntax           as G


instance BackendTransport 'MySQL where
  runDBQuery        = runQuery
  runDBQueryExplain = error "runDBQueryExplain: MySQL backend does not support this operation yet."
  runDBMutation     = error "runDBMutation: MySQL backend does not support this operation yet."
  runDBSubscription = error "runDBSubscription: MySQL backend does not support this operation yet."

runQuery
  :: ( MonadIO m
     , MonadQueryLog m
     , MonadTrace m
     , MonadError QErr m
     )
  => RequestId
  -> GQLReqUnparsed
  -> G.Name
  -> UserInfo
  -> L.Logger L.Hasura
  -> SourceConfig 'MySQL
  -> ExceptT QErr IO EncJSON
  -> Maybe (PreparedQuery 'MySQL)
  -> m (DiffTime, EncJSON)
  -- ^ Also return the time spent in the PG query; for telemetry.
runQuery reqId query fieldName _userInfo logger _sourceConfig tx genSql =  do
  logQueryLog logger $ mkQueryLog query fieldName genSql reqId
  withElapsedTime
    $ trace ("MySQL Query for root field " <>> fieldName)
    $ run tx

run :: (MonadIO m, MonadError QErr m) => ExceptT QErr IO a -> m a
run action = do
  result <- liftIO $ runExceptT action
  result `onLeft` throwError

mkQueryLog
  :: GQLReqUnparsed
  -> G.Name
  -> Maybe (PreparedQuery 'MySQL)
  -> RequestId
  -> QueryLog
mkQueryLog gqlQuery fieldName preparedSql requestId =
  QueryLog gqlQuery ((fieldName,) <$> generatedQuery) requestId QueryLogKindDatabase
  where
    generatedQuery =
      preparedSql <&> \queryString
        -> GeneratedQuery queryString J.Null