graphql-engine/server/src-lib/Hasura/GraphQL/Resolve/Select.hs

282 lines
10 KiB
Haskell

{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE MultiWayIf #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TupleSections #-}
module Hasura.GraphQL.Resolve.Select
( convertSelect
, convertSelectByPKey
, convertAggSelect
, parseColumns
, withSelSet
, fromSelSet
, fieldAsPath
, fromField
, fromFieldByPKey
, fromAggField
) where
import Data.Has
import Hasura.Prelude
import qualified Data.HashMap.Strict as Map
import qualified Data.HashMap.Strict.InsOrd as OMap
import qualified Data.List.NonEmpty as NE
import qualified Language.GraphQL.Draft.Syntax as G
import qualified Hasura.RQL.DML.Select as RS
import qualified Hasura.SQL.DML as S
import Hasura.GraphQL.Resolve.BoolExp
import Hasura.GraphQL.Resolve.Context
import Hasura.GraphQL.Resolve.InputValue
import Hasura.GraphQL.Schema (isAggFld)
import Hasura.GraphQL.Validate.Field
import Hasura.GraphQL.Validate.Types
import Hasura.RQL.DML.Internal (onlyPositiveInt)
import Hasura.RQL.Types
import Hasura.SQL.Types
import Hasura.SQL.Value
withSelSet :: (Monad m) => SelSet -> (Field -> m a) -> m [(Text, a)]
withSelSet selSet f =
forM (toList selSet) $ \fld -> do
res <- f fld
return (G.unName $ G.unAlias $ _fAlias fld, res)
fromSelSet
:: (MonadError QErr m, MonadReader r m, Has FieldMap r, Has OrdByCtx r)
=> ((PGColType, PGColValue) -> m S.SQLExp)
-> G.NamedType
-> SelSet
-> m [(FieldName, RS.AnnFld)]
fromSelSet f fldTy flds =
forM (toList flds) $ \fld -> do
let fldName = _fName fld
let rqlFldName = FieldName $ G.unName $ G.unAlias $ _fAlias fld
(rqlFldName,) <$> case fldName of
"__typename" -> return $ RS.FExp $ G.unName $ G.unNamedType fldTy
_ -> do
fldInfo <- getFldInfo fldTy fldName
case fldInfo of
Left colInfo -> return $ RS.FCol colInfo
Right (relInfo, isAgg, tableFilter, tableLimit) -> do
let relTN = riRTable relInfo
colMapping = riMapping relInfo
if isAgg then do
aggSel <- fromAggField f relTN tableFilter tableLimit fld
return $ RS.FAgg $ RS.AggSel colMapping aggSel
else do
annSel <- fromField f relTN tableFilter tableLimit fld
let annRel = RS.AnnRel (riName relInfo) (riType relInfo)
colMapping annSel
return $ RS.FRel annRel
fieldAsPath :: (MonadError QErr m) => Field -> m a -> m a
fieldAsPath = nameAsPath . _fName
parseTableArgs
:: (MonadError QErr m, MonadReader r m, Has FieldMap r, Has OrdByCtx r)
=> ((PGColType, PGColValue) -> m S.SQLExp)
-> QualifiedTable -> ArgsMap -> m RS.TableArgs
parseTableArgs f tn args = do
whereExpM <- withArgM args "where" $ convertBoolExpG f tn
ordByExpML <- withArgM args "order_by" parseOrderBy
let ordByExpM = NE.nonEmpty =<< ordByExpML
limitExpM <- withArgM args "limit" parseLimit
offsetExpM <- withArgM args "offset" $ asPGColVal >=> f
return $ RS.TableArgs whereExpM ordByExpM limitExpM offsetExpM
fromField
:: (MonadError QErr m, MonadReader r m, Has FieldMap r, Has OrdByCtx r)
=> ((PGColType, PGColValue) -> m S.SQLExp)
-> QualifiedTable -> S.BoolExp -> Maybe Int -> Field -> m RS.AnnSel
fromField f tn permFilter permLimitM fld =
fieldAsPath fld $ do
tableArgs <- parseTableArgs f tn args
annFlds <- fromSelSet f (_fType fld) $ _fSelSet fld
let tabFrom = RS.TableFrom tn Nothing
tabPerm = RS.TablePerm permFilter permLimitM
return $ RS.AnnSelG annFlds tabFrom tabPerm tableArgs
where
args = _fArguments fld
getOrdByItemMap
:: ( MonadError QErr m
, MonadReader r m
, Has OrdByCtx r
)
=> G.NamedType -> m OrdByItemMap
getOrdByItemMap nt = do
ordByCtx <- asks getter
onNothing (Map.lookup nt ordByCtx) $
throw500 $ "could not lookup " <> showNamedTy nt
parseOrderBy
:: ( MonadError QErr m
, MonadReader r m
, Has OrdByCtx r
)
=> AnnGValue -> m [RS.AnnOrderByItem]
parseOrderBy = fmap concat . withArray f
where
f _ = mapM (withObject (getAnnObItems id))
getAnnObItems
:: ( MonadError QErr m
, MonadReader r m
, Has OrdByCtx r
)
=> (RS.AnnObCol -> RS.AnnObCol)
-> G.NamedType
-> AnnGObject
-> m [RS.AnnOrderByItem]
getAnnObItems f nt obj = do
ordByItemMap <- getOrdByItemMap nt
fmap concat $ forM (OMap.toList obj) $ \(k, v) -> do
ordByItem <- onNothing (Map.lookup k ordByItemMap) $ throw500 $
"cannot lookup " <> showName k <> " order by item in "
<> showNamedTy nt <> " map"
case ordByItem of
OBIPGCol ci -> do
let aobCol = f $ RS.AOCPG ci
(_, enumVal) <- asEnumVal v
(ordTy, nullsOrd) <- parseOrderByEnum enumVal
return [OrderByItemG (Just ordTy) aobCol (Just nullsOrd)]
OBIRel ri fltr -> do
let annObColFn = f . RS.AOCRel ri fltr
withObject (getAnnObItems annObColFn) v
parseOrderByEnum
:: (MonadError QErr m)
=> G.EnumValue
-> m (S.OrderType, S.NullsOrder)
parseOrderByEnum = \case
G.EnumValue "asc" -> return (S.OTAsc, S.NLast)
G.EnumValue "desc" -> return (S.OTDesc, S.NLast)
G.EnumValue "asc_nulls_first" -> return (S.OTAsc, S.NFirst)
G.EnumValue "desc_nulls_first" -> return (S.OTDesc, S.NFirst)
G.EnumValue v -> throw500 $
"enum value " <> showName v <> " not found in type order_by"
parseLimit :: ( MonadError QErr m ) => AnnGValue -> m Int
parseLimit v = do
(_, pgColVal) <- asPGColVal v
limit <- maybe noIntErr return $ pgColValueToInt pgColVal
-- validate int value
onlyPositiveInt limit
return limit
where
noIntErr = throw400 Unexpected "expecting Integer value for \"limit\""
fromFieldByPKey
:: (MonadError QErr m, MonadReader r m, Has FieldMap r, Has OrdByCtx r)
=> ((PGColType, PGColValue) -> m S.SQLExp)
-> QualifiedTable -> S.BoolExp -> Field -> m RS.AnnSel
fromFieldByPKey f tn permFilter fld = fieldAsPath fld $ do
boolExp <- pgColValToBoolExpG f tn $ _fArguments fld
annFlds <- fromSelSet f (_fType fld) $ _fSelSet fld
let tabFrom = RS.TableFrom tn Nothing
tabPerm = RS.TablePerm permFilter Nothing
return $ RS.AnnSelG annFlds tabFrom tabPerm $
RS.noTableArgs { RS._taWhere = Just boolExp}
convertSelect
:: QualifiedTable -> S.BoolExp -> Maybe Int -> Field -> Convert RespTx
convertSelect qt permFilter permLimit fld = do
selData <- withPathK "selectionSet" $
fromField prepare qt permFilter permLimit fld
prepArgs <- get
return $ RS.selectP2 False (selData, prepArgs)
convertSelectByPKey
:: QualifiedTable -> S.BoolExp -> Field -> Convert RespTx
convertSelectByPKey qt permFilter fld = do
selData <- withPathK "selectionSet" $
fromFieldByPKey prepare qt permFilter fld
prepArgs <- get
return $ RS.selectP2 True (selData, prepArgs)
-- agg select related
parseColumns :: MonadError QErr m => AnnGValue -> m [PGCol]
parseColumns val =
flip withArray val $ \_ vals ->
forM vals $ \v -> do
(_, enumVal) <- asEnumVal v
return $ PGCol $ G.unName $ G.unEnumValue enumVal
convertCount :: MonadError QErr m => ArgsMap -> m S.CountType
convertCount args = do
columnsM <- withArgM args "columns" parseColumns
isDistinct <- or <$> withArgM args "distinct" parseDistinct
maybe (return S.CTStar) (mkCType isDistinct) columnsM
where
parseDistinct v = do
(_, val) <- asPGColVal v
case val of
PGValBoolean b -> return b
_ ->
throw500 "expecting Boolean for \"distinct\""
mkCType isDistinct cols = return $
bool (S.CTSimple cols) (S.CTDistinct cols) isDistinct
convertColFlds
:: Monad m => G.NamedType -> SelSet -> m RS.ColFlds
convertColFlds ty selSet =
withSelSet selSet $ \fld ->
case _fName fld of
"__typename" -> return $ RS.PCFExp $ G.unName $ G.unNamedType ty
n -> return $ RS.PCFCol $ PGCol $ G.unName n
convertAggFld
:: (Monad m, MonadError QErr m)
=> G.NamedType -> SelSet -> m RS.AggFlds
convertAggFld ty selSet =
withSelSet selSet $ \fld -> do
let fType = _fType fld
fSelSet = _fSelSet fld
case _fName fld of
"__typename" -> return $ RS.AFExp $ G.unName $ G.unNamedType ty
"count" -> RS.AFCount <$> convertCount (_fArguments fld)
n -> do
colFlds <- convertColFlds fType fSelSet
unless (isAggFld n) $ throwInvalidFld n
return $ RS.AFOp $ RS.AggOp (G.unName n) colFlds
where
throwInvalidFld (G.Name t) =
throw500 $ "unexpected field in _aggregate node: " <> t
fromAggField
:: (MonadError QErr m, MonadReader r m, Has FieldMap r, Has OrdByCtx r)
=> ((PGColType, PGColValue) -> m S.SQLExp)
-> QualifiedTable -> S.BoolExp -> Maybe Int -> Field -> m RS.AnnAggSel
fromAggField fn tn permFilter permLimitM fld = fieldAsPath fld $ do
tableArgs <- parseTableArgs fn tn args
aggSelFlds <- fromAggSel (_fType fld) $ _fSelSet fld
let tabFrom = RS.TableFrom tn Nothing
tabPerm = RS.TablePerm permFilter permLimitM
return $ RS.AnnSelG aggSelFlds tabFrom tabPerm tableArgs
where
args = _fArguments fld
fromAggSel ty selSet =
withSelSet selSet $ \f -> do
let fTy = _fType f
fSelSet = _fSelSet f
case _fName f of
"__typename" -> return $ RS.TAFExp $ G.unName $ G.unNamedType ty
"aggregate" -> RS.TAFAgg <$> convertAggFld fTy fSelSet
"nodes" -> RS.TAFNodes <$> fromSelSet fn fTy fSelSet
G.Name t -> throw500 $ "unexpected field in _agg node: " <> t
convertAggSelect
:: QualifiedTable -> S.BoolExp -> Maybe Int -> Field -> Convert RespTx
convertAggSelect qt permFilter permLimit fld = do
selData <- withPathK "selectionSet" $
fromAggField prepare qt permFilter permLimit fld
prepArgs <- get
return $ RS.selectAggP2 (selData, prepArgs)