graphql-engine/server/src-lib/Hasura/Backends/BigQuery/Instances/Schema.hs

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

module Hasura.Backends.BigQuery.Instances.Schema () where

import Data.Aeson qualified as J
import Data.Has
import Data.HashMap.Strict qualified as Map
import Data.List.NonEmpty qualified as NE
import Data.Text qualified as T
import Data.Text.Extended
import Hasura.Backends.BigQuery.Types qualified as BigQuery
import Hasura.Base.Error
import Hasura.GraphQL.Parser hiding (EnumValueInfo, field)
import Hasura.GraphQL.Parser qualified as P
import Hasura.GraphQL.Parser.Internal.Parser hiding (field)
import Hasura.GraphQL.Schema.Backend
import Hasura.GraphQL.Schema.BoolExp
import Hasura.GraphQL.Schema.Build qualified as GSB
import Hasura.GraphQL.Schema.Common
import Hasura.GraphQL.Schema.Select
import Hasura.Prelude
import Hasura.RQL.IR.Select qualified as IR
import Hasura.RQL.Types
import Language.GraphQL.Draft.Syntax qualified as G

----------------------------------------------------------------
-- BackendSchema instance

instance BackendSchema 'BigQuery where
  -- top level parsers
  buildTableQueryFields = GSB.buildTableQueryFields
  buildTableRelayQueryFields = bqBuildTableRelayQueryFields
  buildTableInsertMutationFields = bqBuildTableInsertMutationFields
  buildTableUpdateMutationFields = bqBuildTableUpdateMutationFields
  buildTableDeleteMutationFields = bqBuildTableDeleteMutationFields
  buildFunctionQueryFields = bqBuildFunctionQueryFields
  buildFunctionRelayQueryFields = bqBuildFunctionRelayQueryFields
  buildFunctionMutationFields = bqBuildFunctionMutationFields

  -- backend extensions
  relayExtension = Nothing
  nodesAggExtension = Just ()

  -- table arguments
  tableArguments = defaultTableArgs

  -- indivdual components
  columnParser = bqColumnParser
  jsonPathArg = bqJsonPathArg
  orderByOperators = bqOrderByOperators
  comparisonExps = bqComparisonExps
  mkCountType = bqMkCountType
  aggregateOrderByCountType = BigQuery.IntegerScalarType
  computedField = bqComputedField
  node = bqNode

  -- SQL literals
  columnDefaultValue = error "TODO: Make impossible by the type system. BigQuery doesn't support insertions."

----------------------------------------------------------------
-- Top level parsers

bqBuildTableRelayQueryFields ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  TableName 'BigQuery ->
  TableInfo 'BigQuery ->
  G.Name ->
  NESeq (ColumnInfo 'BigQuery) ->
  SelPermInfo 'BigQuery ->
  m [a]
bqBuildTableRelayQueryFields _sourceName _tableName _tableInfo _gqlName _pkeyColumns _selPerms =
  pure []

bqBuildTableInsertMutationFields ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  TableName 'BigQuery ->
  TableInfo 'BigQuery ->
  G.Name ->
  InsPermInfo 'BigQuery ->
  Maybe (SelPermInfo 'BigQuery) ->
  Maybe (UpdPermInfo 'BigQuery) ->
  m [a]
bqBuildTableInsertMutationFields _sourceName _tableName _tableInfo _gqlName _insPerms _selPerms _updPerms =
  pure []

bqBuildTableUpdateMutationFields ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  TableName 'BigQuery ->
  TableInfo 'BigQuery ->
  G.Name ->
  UpdPermInfo 'BigQuery ->
  Maybe (SelPermInfo 'BigQuery) ->
  m [a]
bqBuildTableUpdateMutationFields _sourceName _tableName _tableInfo _gqlName _updPerns _selPerms =
  pure []

bqBuildTableDeleteMutationFields ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  TableName 'BigQuery ->
  TableInfo 'BigQuery ->
  G.Name ->
  DelPermInfo 'BigQuery ->
  Maybe (SelPermInfo 'BigQuery) ->
  m [a]
bqBuildTableDeleteMutationFields _sourceName _tableName _tableInfo _gqlName _delPerns _selPerms =
  pure []

bqBuildFunctionQueryFields ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  FunctionName 'BigQuery ->
  FunctionInfo 'BigQuery ->
  TableName 'BigQuery ->
  SelPermInfo 'BigQuery ->
  m [a]
bqBuildFunctionQueryFields _ _ _ _ _ =
  pure []

bqBuildFunctionRelayQueryFields ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  FunctionName 'BigQuery ->
  FunctionInfo 'BigQuery ->
  TableName 'BigQuery ->
  NESeq (ColumnInfo 'BigQuery) ->
  SelPermInfo 'BigQuery ->
  m [a]
bqBuildFunctionRelayQueryFields _sourceName _functionName _functionInfo _tableName _pkeyColumns _selPerms =
  pure []

bqBuildFunctionMutationFields ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  FunctionName 'BigQuery ->
  FunctionInfo 'BigQuery ->
  TableName 'BigQuery ->
  SelPermInfo 'BigQuery ->
  m [a]
bqBuildFunctionMutationFields _ _ _ _ _ =
  pure []

----------------------------------------------------------------
-- Individual components

bqColumnParser ::
  (MonadSchema n m, MonadError QErr m, MonadReader r m, Has MkTypename r) =>
  ColumnType 'BigQuery ->
  G.Nullability ->
  m (Parser 'Both n (ValueWithOrigin (ColumnValue 'BigQuery)))
bqColumnParser columnType (G.Nullability isNullable) =
  peelWithOrigin . fmap (ColumnValue columnType) <$> case columnType of
    ColumnScalar scalarType -> case scalarType of
      -- bytestrings
      -- we only accept string literals
      BigQuery.BytesScalarType -> pure $ possiblyNullable scalarType $ BigQuery.StringValue <$> P.string
      -- text
      BigQuery.StringScalarType -> pure $ possiblyNullable scalarType $ BigQuery.StringValue <$> P.string
      -- floating point values
      -- TODO: we do not perform size checks here, meaning we would accept an
      -- out-of-bounds value as long as it can be represented by a GraphQL float; this
      -- will in all likelihood error on the BigQuery side. Do we want to handle those
      -- properly here?
      BigQuery.FloatScalarType -> pure $ possiblyNullable scalarType $ BigQuery.FloatValue . BigQuery.doubleToFloat64 <$> P.float
      BigQuery.IntegerScalarType -> pure $ possiblyNullable scalarType $ BigQuery.IntegerValue . BigQuery.intToInt64 . fromIntegral <$> P.int
      BigQuery.DecimalScalarType -> pure $ possiblyNullable scalarType $ BigQuery.DecimalValue . BigQuery.doubleToDecimal <$> P.float
      BigQuery.BigDecimalScalarType -> pure $ possiblyNullable scalarType $ BigQuery.BigDecimalValue . BigQuery.doubleToBigDecimal <$> P.float
      -- boolean type
      BigQuery.BoolScalarType -> pure $ possiblyNullable scalarType $ BigQuery.BoolValue <$> P.boolean
      BigQuery.DateScalarType -> pure $ possiblyNullable scalarType $ BigQuery.DateValue . BigQuery.Date <$> P.string
      BigQuery.TimeScalarType -> pure $ possiblyNullable scalarType $ BigQuery.TimeValue . BigQuery.Time <$> P.string
      BigQuery.DatetimeScalarType -> pure $ possiblyNullable scalarType $ BigQuery.DatetimeValue . BigQuery.Datetime <$> P.string
      BigQuery.GeographyScalarType -> pure $ possiblyNullable scalarType $ BigQuery.GeographyValue . BigQuery.Geography <$> P.string
      BigQuery.TimestampScalarType -> do
        let schemaType = P.TNamed P.Nullable $ P.Definition stringScalar Nothing P.TIScalar
        pure $
          possiblyNullable scalarType $
            Parser
              { pType = schemaType,
                pParser =
                  valueToJSON (P.toGraphQLType schemaType)
                    >=> fmap (BigQuery.StringValue . BigQuery.utctimeToISO8601Text)
                      . either (parseErrorWith ParseFailed . qeError) pure
                      . runAesonParser (J.withText "TimestampColumn" BigQuery.textToUTCTime)
              }
      ty -> throwError $ internalError $ T.pack $ "Type currently unsupported for BigQuery: " ++ show ty
    ColumnEnumReference (EnumReference tableName enumValues) ->
      case nonEmpty (Map.toList enumValues) of
        Just enumValuesList -> do
          tableGQLName <- tableGraphQLName @'BigQuery tableName `onLeft` throwError
          enumName <- P.mkTypename $ tableGQLName <> $$(G.litName "_enum")
          pure $ possiblyNullable BigQuery.StringScalarType $ P.enum enumName Nothing (mkEnumValue <$> enumValuesList)
        Nothing -> throw400 ValidationFailed "empty enum values"
  where
    possiblyNullable _scalarType
      | isNullable = fmap (fromMaybe BigQuery.NullValue) . P.nullable
      | otherwise = id
    mkEnumValue :: (EnumValue, EnumValueInfo) -> (P.Definition P.EnumValueInfo, ScalarValue 'BigQuery)
    mkEnumValue (EnumValue value, EnumValueInfo description) =
      ( P.Definition value (G.Description <$> description) P.EnumValueInfo,
        BigQuery.StringValue $ G.unName value
      )
    throughJSON scalarName =
      let schemaType = P.TNamed P.NonNullable $ P.Definition scalarName Nothing P.TIScalar
       in Parser
            { pType = schemaType,
              pParser =
                valueToJSON (P.toGraphQLType schemaType)
                  >=> either (parseErrorWith ParseFailed . qeError) pure . runAesonParser J.parseJSON
            }

bqJsonPathArg ::
  MonadParse n =>
  ColumnType 'BigQuery ->
  InputFieldsParser n (Maybe (IR.ColumnOp 'BigQuery))
bqJsonPathArg _columnType = pure Nothing

bqOrderByOperators ::
  NonEmpty
    ( Definition P.EnumValueInfo,
      (BasicOrderType 'BigQuery, NullsOrderType 'BigQuery)
    )
bqOrderByOperators =
  NE.fromList
    [ ( define $$(G.litName "asc") "in ascending order, nulls first",
        (BigQuery.AscOrder, BigQuery.NullsFirst)
      ),
      ( define $$(G.litName "asc_nulls_first") "in ascending order, nulls first",
        (BigQuery.AscOrder, BigQuery.NullsFirst)
      ),
      ( define $$(G.litName "asc_nulls_last") "in ascending order, nulls last",
        (BigQuery.AscOrder, BigQuery.NullsLast)
      ),
      ( define $$(G.litName "desc") "in descending order, nulls last",
        (BigQuery.DescOrder, BigQuery.NullsLast)
      ),
      ( define $$(G.litName "desc_nulls_first") "in descending order, nulls first",
        (BigQuery.DescOrder, BigQuery.NullsFirst)
      ),
      ( define $$(G.litName "desc_nulls_last") "in descending order, nulls last",
        (BigQuery.DescOrder, BigQuery.NullsLast)
      )
    ]
  where
    define name desc = P.Definition name (Just desc) P.EnumValueInfo

bqComparisonExps ::
  forall m n r.
  (BackendSchema 'BigQuery, MonadSchema n m, MonadError QErr m, MonadReader r m, Has QueryContext r, Has MkTypename r) =>
  ColumnType 'BigQuery ->
  m (Parser 'Input n [ComparisonExp 'BigQuery])
bqComparisonExps = P.memoize 'comparisonExps $ \columnType -> do
  collapseIfNull <- asks $ qcDangerousBooleanCollapse . getter
  -- see Note [Columns in comparison expression are never nullable]
  typedParser <- columnParser columnType (G.Nullability False)
  nullableTextParser <- columnParser (ColumnScalar @'BigQuery BigQuery.StringScalarType) (G.Nullability True)
  -- textParser <- columnParser (ColumnScalar @'BigQuery BigQuery.StringScalarType) (G.Nullability False)
  let name = P.getName typedParser <> $$(G.litName "_BigQuery_comparison_exp")
      desc =
        G.Description $
          "Boolean expression to compare columns of type "
            <> P.getName typedParser
            <<> ". All fields are combined with logical 'AND'."
      -- textListParser = fmap openValueOrigin <$> P.list textParser
      columnListParser = fmap openValueOrigin <$> P.list typedParser
      mkListLiteral :: [ColumnValue 'BigQuery] -> UnpreparedValue 'BigQuery
      mkListLiteral =
        P.UVLiteral . BigQuery.ListExpression . fmap (BigQuery.ValueExpression . cvValue)
  pure $
    P.object name (Just desc) $
      fmap catMaybes $
        sequenceA $
          concat
            [ equalityOperators
                collapseIfNull
                (mkParameter <$> typedParser)
                (mkListLiteral <$> columnListParser),
              comparisonOperators
                collapseIfNull
                (mkParameter <$> typedParser)
            ]

bqMkCountType ::
  -- | distinct values
  Maybe Bool ->
  Maybe [Column 'BigQuery] ->
  CountType 'BigQuery
bqMkCountType _ Nothing = BigQuery.StarCountable
bqMkCountType (Just True) (Just cols) =
  maybe BigQuery.StarCountable BigQuery.DistinctCountable $ nonEmpty cols
bqMkCountType _ (Just cols) =
  maybe BigQuery.StarCountable BigQuery.NonNullFieldCountable $ nonEmpty cols

-- | Computed field parser.
-- Currently unsupported: returns Nothing for now.
bqComputedField ::
  MonadBuildSchema 'BigQuery r m n =>
  SourceName ->
  ComputedFieldInfo 'BigQuery ->
  TableName 'BigQuery ->
  SelPermInfo 'BigQuery ->
  m (Maybe (FieldParser n (AnnotatedField 'BigQuery)))
bqComputedField _sourceName _fieldInfo _table _selectPemissions = pure Nothing

-- | Remote join field parser.
-- Currently unsupported: returns Nothing for now.
bqRemoteRelationshipField ::
  MonadBuildSchema 'BigQuery r m n =>
  RemoteFieldInfo (DBJoinField 'BigQuery) ->
  m (Maybe [FieldParser n (AnnotatedField 'BigQuery)])
bqRemoteRelationshipField _remoteFieldInfo = pure Nothing

-- | The 'node' root field of a Relay request. Relay is currently unsupported on BigQuery,
-- meaning this parser will never be called: any attempt to create this parser should
-- therefore fail.
bqNode ::
  MonadBuildSchema 'BigQuery r m n =>
  m
    ( Parser
        'Output
        n
        ( HashMap
            (TableName 'BigQuery)
            ( SourceName,
              SourceConfig 'BigQuery,
              SelPermInfo 'BigQuery,
              PrimaryKeyColumns 'BigQuery,
              AnnotatedFields 'BigQuery
            )
        )
    )
bqNode = throw500 "BigQuery does not support relay; `node` should never be exposed in the schema."