{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE ViewPatterns #-}

module Hasura.GraphQL.Schema.RemoteTest (spec) where

import Control.Lens (Prism', prism', to, (^..), _Right)
import Data.Aeson qualified as J
import Data.Aeson.Key qualified as K
import Data.Aeson.KeyMap qualified as KM
import Data.ByteString.Lazy qualified as LBS
import Data.HashMap.Strict.Extended qualified as M
import Data.Text qualified as T
import Data.Text.Extended
import Data.Text.RawString
import Hasura.Base.Error
import Hasura.GraphQL.Execute.Inline
import Hasura.GraphQL.Execute.Remote (resolveRemoteVariable, runVariableCache)
import Hasura.GraphQL.Execute.Resolve
import Hasura.GraphQL.Namespace
import Hasura.GraphQL.Parser.Constants qualified as G
import Hasura.GraphQL.Parser.Internal.Parser qualified as P
import Hasura.GraphQL.Parser.Monad (runSchemaT)
import Hasura.GraphQL.Parser.Schema
import Hasura.GraphQL.Parser.TestUtils
import Hasura.GraphQL.Schema.Common
import Hasura.GraphQL.Schema.Remote
import Hasura.Prelude
import Hasura.RQL.IR.RemoteSchema
import Hasura.RQL.IR.Root
import Hasura.RQL.IR.Value
import Hasura.RQL.Types.Common
import Hasura.RQL.Types.RemoteSchema
import Hasura.RQL.Types.SchemaCache
import Hasura.RQL.Types.SourceCustomization
import Hasura.Session
import Language.GraphQL.Draft.Parser qualified as G
import Language.GraphQL.Draft.Syntax qualified as G
import Network.URI qualified as N
import Test.Hspec

-- test tools

runError :: Monad m => ExceptT QErr m a -> m a
runError = runExceptT >=> (`onLeft` (error . T.unpack . qeError))

mkTestRemoteSchema :: Text -> RemoteSchemaIntrospection
mkTestRemoteSchema schema = RemoteSchemaIntrospection $
  M.fromListOn getTypeName $
    runIdentity $
      runError $ do
        G.SchemaDocument types <- G.parseSchemaDocument schema `onLeft` throw500
        pure $ flip mapMaybe types \case
          G.TypeSystemDefinitionSchema _ -> Nothing
          G.TypeSystemDefinitionType td -> Just $ case fmap toRemoteInputValue td of
            G.TypeDefinitionScalar std -> G.TypeDefinitionScalar std
            G.TypeDefinitionObject otd -> G.TypeDefinitionObject otd
            G.TypeDefinitionUnion utd -> G.TypeDefinitionUnion utd
            G.TypeDefinitionEnum etd -> G.TypeDefinitionEnum etd
            G.TypeDefinitionInputObject itd -> G.TypeDefinitionInputObject itd
            G.TypeDefinitionInterface itd ->
              G.TypeDefinitionInterface $
                G.InterfaceTypeDefinition
                  { G._itdDescription = G._itdDescription itd,
                    G._itdName = G._itdName itd,
                    G._itdDirectives = G._itdDirectives itd,
                    G._itdFieldsDefinition = G._itdFieldsDefinition itd,
                    G._itdPossibleTypes = []
                  }
  where
    toRemoteInputValue ivd =
      RemoteSchemaInputValueDefinition
        { _rsitdDefinition = ivd,
          _rsitdPresetArgument =
            choice $
              G._ivdDirectives ivd <&> \dir -> do
                guard $ G._dName dir == G._preset
                value <- M.lookup G._value $ G._dArguments dir
                Just $ case value of
                  G.VString "x-hasura-test" ->
                    G.VVariable $
                      SessionPresetVariable (mkSessionVariable "x-hasura-test") G._String SessionArgumentPresetScalar
                  _ -> absurd <$> value
        }

mkTestExecutableDocument :: Text -> ([G.VariableDefinition], G.SelectionSet G.NoFragments G.Name)
mkTestExecutableDocument t = runIdentity $
  runError $ do
    G.ExecutableDocument execDoc <- G.parseExecutableDoc t `onLeft` throw500
    case execDoc of
      [G.ExecutableDefinitionOperation op] -> case op of
        G.OperationDefinitionUnTyped selSet -> ([],) <$> inlineSelectionSet [] selSet
        G.OperationDefinitionTyped opDef -> do
          unless (G._todType opDef == G.OperationTypeQuery) $
            throw500 "only queries for now"
          resSelSet <- inlineSelectionSet [] $ G._todSelectionSet opDef
          pure (G._todVariableDefinitions opDef, resSelSet)
      _ -> throw500 "must have only one query in the document"

mkTestVariableValues :: LBS.ByteString -> M.HashMap G.Name J.Value
mkTestVariableValues vars = runIdentity $
  runError $ do
    value <- J.eitherDecode vars `onLeft` (throw500 . T.pack)
    case value of
      J.Object vs ->
        M.fromList <$> for (KM.toList vs) \(K.toText -> name, val) -> do
          gname <- G.mkName name `onNothing` throw500 ("wrong Name: " <>> name)
          pure (gname, val)
      _ -> throw500 "variables must be an object"

buildQueryParsers ::
  RemoteSchemaIntrospection ->
  IO (P.FieldParser TestMonad (GraphQLField (RemoteRelationshipField UnpreparedValue) RemoteSchemaVariable))
buildQueryParsers introspection = do
  let introResult = IntrospectionResult introspection G._Query Nothing Nothing
      remoteSchemaInfo = RemoteSchemaInfo (ValidatedRemoteSchemaDef (EnvRecord "" N.nullURI) [] False 60 Nothing) identityCustomizer
      remoteSchemaRels = mempty
      -- Since remote schemas can theoretically join against tables, we need to
      -- have access to all relevant sources-specific information to build their
      -- schema. Here, since there are no relationships to a source in this
      -- test, we are free to give 'undefined' for such fields, as they won't be
      -- evaluated.
      schemaInfo =
        ( adminRoleName :: RoleName,
          mempty :: CustomizeRemoteFieldName,
          mempty :: MkTypename,
          mempty :: MkRootFieldName,
          HasuraCase :: NamingCase,
          undefined :: SchemaOptions,
          SchemaContext
            HasuraSchema
            mempty
            ignoreRemoteRelationship
        )
  RemoteSchemaParser query _ _ <-
    runError $
      flip runReaderT schemaInfo $
        runSchemaT $
          buildRemoteParser introResult remoteSchemaRels remoteSchemaInfo
  pure $
    head query <&> \case
      NotNamespaced remoteFld -> _rfField remoteFld
      Namespaced _ ->
        -- Shouldn't happen if we're using identityCustomizer
        -- TODO: add some tests for remote schema customization
        error "buildQueryParsers: unexpected Namespaced field"

runQueryParser ::
  P.FieldParser TestMonad any ->
  ([G.VariableDefinition], G.SelectionSet G.NoFragments G.Name) ->
  M.HashMap G.Name J.Value ->
  any
runQueryParser parser (varDefs, selSet) vars = runIdentity . runError $ do
  (_, resolvedSelSet) <- resolveVariables varDefs vars [] selSet
  field <- case resolvedSelSet of
    [G.SelectionField f] -> pure f
    _ -> error "expecting only one field in the query"
  runTest (P.fParser parser field) `onLeft` throw500

run ::
  -- | schema
  Text ->
  -- | query
  Text ->
  -- | variables
  LBS.ByteString ->
  IO (GraphQLField (RemoteRelationshipField UnpreparedValue) RemoteSchemaVariable)
run schema query variables = do
  parser <- buildQueryParsers $ mkTestRemoteSchema schema
  pure $
    runQueryParser
      parser
      (mkTestExecutableDocument query)
      (mkTestVariableValues variables)

-- actual test

spec :: Spec
spec = do
  testNoVarExpansionIfNoPreset
  testNoVarExpansionIfNoPresetUnlessTopLevelOptionalField
  testPartialVarExpansionIfPreset
  testVariableSubstitutionCollision

testNoVarExpansionIfNoPreset :: Spec
testNoVarExpansionIfNoPreset = it "variables aren't expanded if there's no preset" $ do
  field <-
    run
      -- schema
      [raw|
scalar Int

input A {
  b: B
}

input B {
  c: C
}

input C {
  i: Int
}

type Query {
  test(a: A!): Int
}
|]
      -- query
      [raw|
query($a: A!) {
  test(a: $a)
}
|]
      -- variables
      [raw|
{
  "a": {
    "b": {
      "c": {
        "i": 0
      }
    }
  }
}
|]
  let arg = head $ M.toList $ _fArguments field
  arg
    `shouldBe` ( G._a,
                 -- the parser did not create a new JSON variable, and forwarded the query variable unmodified
                 G.VVariable $
                   QueryVariable $
                     Variable
                       (VIRequired G._a)
                       (G.TypeNamed (G.Nullability False) G._A)
                       (JSONValue $ J.Object $ KM.fromList [("b", J.Object $ KM.fromList [("c", J.Object $ KM.fromList [("i", J.Number 0)])])])
               )

testNoVarExpansionIfNoPresetUnlessTopLevelOptionalField :: Spec
testNoVarExpansionIfNoPresetUnlessTopLevelOptionalField = it "unless fieldOptional peels the variable first" $ do
  field <-
    run
      -- schema
      [raw|
scalar Int

input A {
  b: B
}

input B {
  c: C
}

input C {
  i: Int
}

type Query {
  test(a: A): Int
}
|]
      -- query
      [raw|
query($a: A) {
  test(a: $a)
}
|]
      -- variables
      [raw|
{
  "a": {
    "b": {
      "c": {
        "i": 0
      }
    }
  }
}
|]
  let arg = head $ M.toList $ _fArguments field
  arg
    `shouldBe` ( G._a,
                 -- fieldOptional has peeled the variable; all we see is a JSON blob, and in doubt
                 -- we repackage it as a newly minted JSON variable
                 G.VVariable $
                   RemoteJSONValue
                     (G.TypeNamed (G.Nullability True) G._A)
                     (J.Object $ KM.fromList [("b", J.Object $ KM.fromList [("c", J.Object $ KM.fromList [("i", J.Number 0)])])])
               )

testPartialVarExpansionIfPreset :: Spec
testPartialVarExpansionIfPreset = it "presets cause partial var expansion" $ do
  field <-
    run
      -- schema
      [raw|
scalar Int

input A {
  x: Int @preset(value: 0)
  b: B
}

input B {
  c: C
}

input C {
  i: Int
}

type Query {
  test(a: A!): Int
}
|]
      -- query
      [raw|
query($a: A!) {
  test(a: $a)
}
|]
      -- variables
      [raw|
{
  "a": {
    "b": {
      "c": {
        "i": 0
      }
    }
  }
}
|]
  let arg = head $ M.toList $ _fArguments field
  arg
    `shouldBe` ( G._a,
                 -- the preset has caused partial variable expansion, only up to where it's needed
                 G.VObject $
                   M.fromList
                     [ ( G._x,
                         G.VInt 0
                       ),
                       ( G._b,
                         G.VVariable $
                           RemoteJSONValue
                             (G.TypeNamed (G.Nullability True) G._B)
                             (J.Object $ KM.fromList [("c", J.Object $ KM.fromList [("i", J.Number 0)])])
                       )
                     ]
               )

-- | Regression test for https://github.com/hasura/graphql-engine/issues/7170
testVariableSubstitutionCollision :: Spec
testVariableSubstitutionCollision = it "ensures that remote variables are de-duplicated by type and value, not just by value" $ do
  field <- run schema query variables
  let dummyUserInfo =
        UserInfo
          adminRoleName
          (mempty @SessionVariables)
          BOFADisallowed
  eField <-
    runExceptT
      . runVariableCache
      . traverse (resolveRemoteVariable dummyUserInfo)
      $ field
  let variableNames =
        eField ^.. _Right . to _fArguments . traverse . _VVariable . to vInfo . to getName . to G.unName
  variableNames `shouldBe` ["hasura_json_var_1", "hasura_json_var_2"]
  where
    -- A schema whose values are representable as collections of JSON values.
    schema :: Text
    schema =
      [raw|
scalar Int
scalar String

type Query {
  test(a: [Int], b: [String]): Int
}
|]
    -- A query against values from 'schema' using JSON variable substitution.
    query :: Text
    query =
      [raw|
query($a: [Int], $b: [String]) {
  test(a: $a, b: $b)
}
|]
    -- Two identical JSON variables to substitute; 'schema' and 'query' declare
    -- that these variables should have different types despite both being
    -- empty collections.
    variables :: LBS.ByteString
    variables =
      [raw|
{
  "a": [],
  "b": []
}
|]

-- | Convenience function to focus on a 'G.VVariable' when pulling test values
-- out in 'testVariableSubstitutionCollision'.
_VVariable :: Prism' (G.Value var) var
_VVariable = prism' upcast downcast
  where
    upcast = G.VVariable
    downcast = \case
      G.VVariable var -> Just var
      _ -> Nothing