graphql-engine/server/src-lib/Hasura/Backends/BigQuery/DDL/RunSQL.hs

{-# LANGUAGE TemplateHaskell #-}

-- |
-- Working example:
--
-- \$ curl -XPOST http://localhost:8080/v2/query -d @- <<EOF
-- {
--   "type":"bigquery_run_sql",
--   "args": {
--     "sql":"select 3 * 4 as foo, \"Hello, World!\" as bar",
--     "source":"chinook"
--   }
-- }
-- EOF
-- {"result_type":"TuplesOk","result":[["foo","bar"],["12","Hello, World!"]]}
module Hasura.Backends.BigQuery.DDL.RunSQL
  ( runSQL,
    runDatabaseInspection,
    BigQueryRunSQL,
  )
where

import Data.Aeson qualified as J
import Data.Aeson.TH (deriveJSON)
import Data.Aeson.Text (encodeToLazyText)
import Data.HashMap.Strict.InsOrd qualified as OMap
import Data.Text qualified as T
import Data.Text.Lazy qualified as LT
import Data.Vector qualified as V
import Hasura.Backends.BigQuery.Execute qualified as Execute
import Hasura.Backends.BigQuery.Source (BigQuerySourceConfig (..))
import Hasura.Base.Error
import Hasura.EncJSON
import Hasura.Prelude
import Hasura.RQL.DDL.Schema (RunSQLRes (..))
import Hasura.RQL.Types (CacheRWM, MetadataM, SourceName, askSourceConfig)
import Hasura.SQL.Backend

data BigQueryRunSQL = BigQueryRunSQL
  { _mrsSql :: Text,
    _mrsSource :: !SourceName
  }
  deriving (Show, Eq)

$(deriveJSON hasuraJSON ''BigQueryRunSQL)

runSQL ::
  (MonadIO m, CacheRWM m, MonadError QErr m, MetadataM m) =>
  BigQueryRunSQL ->
  m EncJSON
runSQL = runSQL_ recordSetAsHeaderAndRows

-- | The SQL query in the request is ignored
runDatabaseInspection ::
  (MonadIO m, CacheRWM m, MonadError QErr m, MetadataM m) =>
  BigQueryRunSQL ->
  m EncJSON
runDatabaseInspection (BigQueryRunSQL _query source) = do
  BigQuerySourceConfig {_scDatasets = dataSets} <- askSourceConfig @'BigQuery source
  let queries =
        [ "SELECT *, ARRAY(SELECT as STRUCT * from "
            <> dataSet
            <> ".INFORMATION_SCHEMA.COLUMNS WHERE table_name = t.table_name) as columns from "
            <> dataSet
            <> ".INFORMATION_SCHEMA.TABLES as t"
          | dataSet <- dataSets
        ]
      query' = T.intercalate " UNION ALL " queries
  runSQL_ recordSetAsSchema (BigQueryRunSQL query' source)

runSQL_ ::
  (MonadIO m, CacheRWM m, MonadError QErr m, MetadataM m) =>
  (Execute.RecordSet -> J.Value) ->
  BigQueryRunSQL ->
  m EncJSON
runSQL_ f (BigQueryRunSQL query source) = do
  sourceConfig <- askSourceConfig @'BigQuery source
  result <-
    Execute.streamBigQuery
      (_scConnection sourceConfig)
      Execute.BigQuery {query = LT.fromStrict query, parameters = mempty}
  case result of
    Left queryError -> throw400 BigQueryError (tshow queryError) -- TODO: Pretty print the error type.
    Right recordSet ->
      pure
        ( encJFromJValue
            (RunSQLRes "TuplesOk" (f recordSet))
        )

recordSetAsHeaderAndRows :: Execute.RecordSet -> J.Value
recordSetAsHeaderAndRows Execute.RecordSet {rows} = J.toJSON (thead : tbody)
  where
    thead =
      case rows V.!? 0 of
        Nothing -> []
        Just row ->
          map (J.toJSON . (coerce :: Execute.FieldNameText -> Text)) (OMap.keys row)
    tbody :: [[J.Value]]
    tbody = map (map J.toJSON . OMap.elems) (toList rows)

recordSetAsSchema :: Execute.RecordSet -> J.Value
recordSetAsSchema rs@(Execute.RecordSet {rows}) =
  recordSetAsHeaderAndRows $
    rs
      { Execute.rows =
          OMap.adjust
            (Execute.TextOutputValue . LT.toStrict . encodeToLazyText . J.toJSON)
            (Execute.FieldNameText "columns")
            <$> rows
      }