DTR-3423: Check allow list if the user directly calls the landing page

app/controllers/LandingController.scala

@@ -16,7 +16,7 @@
 
 package controllers
 
-import controllers.actions.IdentifierAction
+import controllers.actions.{AllowListFilterAction, IdentifierAction}
 import play.api.Logging
 import play.api.i18n.I18nSupport
 import play.api.mvc.{Action, AnyContent, MessagesControllerComponents}
@@ -28,18 +28,20 @@ import scala.concurrent.ExecutionContext
 
 class LandingController @Inject() (nddService: NationalDirectDebitService,
                                    val controllerComponents: MessagesControllerComponents,
-                                   identify: IdentifierAction
+                                   identify: IdentifierAction,
+                                   allowListFilter: AllowListFilterAction
                                   )(implicit ec: ExecutionContext)
     extends FrontendBaseController
     with I18nSupport
     with Logging {
 
-  def onPageLoad(): Action[AnyContent] = identify.async { implicit request =>
-    nddService.retrieveAllDirectDebits(request.userId) map {
-      case rdsResponse if rdsResponse.directDebitCount == 0 =>
+  def onPageLoad(): Action[AnyContent] = (identify andThen allowListFilter).async { implicit request =>
+    nddService.retrieveAllDirectDebits(request.userId).map { rdsResponse =>
+      if (rdsResponse.directDebitCount == 0) {
         Redirect(routes.SetupDirectDebitPaymentController.onPageLoad())
-      case response =>
+      } else {
         Redirect(routes.YourDirectDebitInstructionsController.onPageLoad())
+      }
     }
   }
 }

app/controllers/SetupDirectDebitPaymentController.scala

@@ -34,12 +34,13 @@ class SetupDirectDebitPaymentController @Inject() (
   nddService: NationalDirectDebitService,
   val controllerComponents: MessagesControllerComponents,
   view: SetupDirectDebitPaymentView,
-  lockService: LockService
+  lockService: LockService,
+  allowListFilter: AllowListFilterAction
 )(implicit ec: ExecutionContext)
     extends FrontendBaseController
     with I18nSupport {
 
-  def onPageLoad(): Action[AnyContent] = (identify andThen getData).async { implicit request =>
+  def onPageLoad(): Action[AnyContent] = (identify andThen allowListFilter andThen getData).async { implicit request =>
     lockService.isUserLocked(request.userId) flatMap {
       _.lockStatus match
         case NotLocked =>

app/controllers/YourBankDetailsController.scala

@@ -76,7 +76,7 @@ class YourBankDetailsController @Inject() (
 
       personalOrBusinessOpt match {
         case None =>
-          logger.warn(s"Missing PersonalOrBusinessAccountPage for user: $credId")
+          logger.warn(s"Missing PersonalOrBusinessAccountPage for user")
           Future.successful(Redirect(routes.SystemErrorController.onPageLoad()))
 
         case Some(accountType) =>

app/controllers/YourDirectDebitInstructionsController.scala

@@ -40,12 +40,13 @@ class YourDirectDebitInstructionsController @Inject() (
   appConfig: FrontendAppConfig,
   nddService: NationalDirectDebitService,
   paginationService: PaginationService,
-  sessionRepository: SessionRepository
+  sessionRepository: SessionRepository,
+  allowListFilter: AllowListFilterAction
 )(implicit ec: ExecutionContext)
     extends FrontendBaseController
     with I18nSupport {
 
-  def onPageLoad: Action[AnyContent] = (identify andThen getData).async { implicit request =>
+  def onPageLoad: Action[AnyContent] = (identify andThen allowListFilter andThen getData).async { implicit request =>
     val userAnswers = request.userAnswers.getOrElse(UserAnswers(request.userId))
     val currentPage = request.getQueryString("page").flatMap(_.toIntOption).getOrElse(1)
 

app/controllers/actions/AllowListFilterAction.scala

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2026 HM Revenue & Customs
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package controllers.actions
+
+import models.requests.IdentifierRequest
+import play.api.mvc.{ActionFilter, Result}
+import play.api.{Configuration, Logging}
+import play.api.mvc.Results.SeeOther
+import splitter.connectors.AllowListConnector
+import uk.gov.hmrc.http.HeaderCarrier
+
+import javax.inject.Inject
+import scala.concurrent.{ExecutionContext, Future}
+import scala.util.control.NonFatal
+
+class AllowListFilterAction @Inject() (connector: AllowListConnector, configuration: Configuration)(implicit val executionContext: ExecutionContext)
+    extends ActionFilter[IdentifierRequest]
+    with Logging {
+
+  private val legacyStartUrl = configuration.get[String]("microservice.services.ndds-legacy.path")
+
+  override protected def filter[A](request: IdentifierRequest[A]): Future[Option[Result]] =
+    implicit val hc: HeaderCarrier = HeaderCarrier()
+    connector
+      .check(request.userId)
+      .map:
+        case true  => None
+        case false => Some(SeeOther(legacyStartUrl))
+      .recover:
+        case NonFatal(e) =>
+          logger.error("Error when checking for user id ", e)
+          Some(SeeOther(legacyStartUrl))
+}

app/services/NationalDirectDebitService.scala

@@ -144,7 +144,7 @@ class NationalDirectDebitService @Inject() (nddConnector: NationalDirectDebitCon
           userAnswers
             .get(YourBankDetailsPage)
             .map(_.auddisStatus)
-            .getOrElse(throw new Exception("YourBankDetailsPage details missing from user answers"))
+            .getOrElse(throw new Exception("Missing information from user answers"))
         )
     }
   }

app/splitter/controllers/SplitterController.scala

@@ -16,7 +16,6 @@
 
 package splitter.controllers
 
-import controllers.actions.IdentifierAction
 import play.api.mvc.*
 import play.api.{Configuration, Logging}
 import splitter.connectors.AllowListConnector

conf/application.conf

@@ -144,7 +144,7 @@ features {
     maxNumberPPsAllowed = 99
     enableLockService = false
     existingDirectDebit = true
-    allowListChecksEnabled = false
+    allowListChecksEnabled = true
 }
 
 mac {

test/controllers/LandingControllerSpec.scala

@@ -22,45 +22,56 @@ import org.mockito.ArgumentMatchers.any
 import org.mockito.Mockito.when
 import org.scalatestplus.mockito.MockitoSugar.mock
 import play.api.inject.bind
+import play.api.inject.guice.GuiceApplicationBuilder
 import play.api.test.FakeRequest
 import play.api.test.Helpers.*
 import services.NationalDirectDebitService
+import splitter.connectors.AllowListConnector
+import splitter.controllers.{FakeIdentityIdentifierAction, IdentityIdentifierAction}
+import uk.gov.hmrc.http.HeaderCarrier
 
 import scala.concurrent.Future
 
 class LandingControllerSpec extends SpecBase {
 
-  "Landing Controller" - {
+  class FakeAllowListConnector(result: Exception | Boolean) extends AllowListConnector:
+    override def check(userId: String)(using HeaderCarrier): Future[Boolean] =
+      result match
+        case res: Boolean   => Future.successful(res)
+        case res: Exception => Future.failed(res)
+
+  private def legacyUrl = "/national-direct-debits"
 
+  "Landing Controller" - {
     val mockService = mock[NationalDirectDebitService]
 
     "must return REDIRECT and the correct view for a GET with no existing debits" in {
-
       val application = applicationBuilder(userAnswers = None)
         .overrides(
-          bind[NationalDirectDebitService].toInstance(mockService)
+          bind[NationalDirectDebitService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(true))
         )
         .build()
 
       running(application) {
-
         when(mockService.retrieveAllDirectDebits(any())(any(), any()))
           .thenReturn(Future.successful(NddResponse(0, Seq())))
 
         val request = FakeRequest(GET, routes.LandingController.onPageLoad().url)
-
         val result = route(application, request).value
 
         status(result) mustEqual SEE_OTHER
-        redirectLocation(result).value must startWith(controllers.routes.SetupDirectDebitPaymentController.onPageLoad().url)
+        redirectLocation(result).value mustBe controllers.routes.SetupDirectDebitPaymentController.onPageLoad().url
       }
     }
 
     "must return REDIRECT and the correct view for a GET with existing debits" in {
-
       val application = applicationBuilder(userAnswers = None)
         .overrides(
-          bind[NationalDirectDebitService].toInstance(mockService)
+          bind[NationalDirectDebitService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(true))
         )
         .build()
 
@@ -70,30 +81,48 @@ class LandingControllerSpec extends SpecBase {
           .thenReturn(Future.successful(NddResponse(2, Seq())))
 
         val request = FakeRequest(GET, routes.LandingController.onPageLoad().url)
-
         val result = route(application, request).value
 
         status(result) mustEqual SEE_OTHER
-        redirectLocation(result).value must startWith(controllers.routes.YourDirectDebitInstructionsController.onPageLoad().url)
+        redirectLocation(result).value mustBe controllers.routes.YourDirectDebitInstructionsController.onPageLoad().url
       }
     }
 
     "must return REDIRECT and the correct view for an unauthenticated user" in {
-
       val application = applicationBuilder(userAnswers = None)
         .overrides(
-          bind[NationalDirectDebitService].toInstance(mockService)
+          bind[NationalDirectDebitService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(true))
         )
         .build()
 
       running(application) {
         val request = FakeRequest(GET, routes.LandingController.onPageLoad().url)
+        val result = route(application, request).value
+
+        status(result) mustEqual SEE_OTHER
+        redirectLocation(result).value mustBe controllers.routes.YourDirectDebitInstructionsController.onPageLoad().url
+      }
+    }
 
+    "must return REDIRECT to legacy url when check is false" in {
+      val application = applicationBuilder(userAnswers = None)
+        .overrides(
+          bind[NationalDirectDebitService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(false))
+        )
+        .build()
+
+      running(application) {
+        val request = FakeRequest(GET, routes.LandingController.onPageLoad().url)
         val result = route(application, request).value
 
         status(result) mustEqual SEE_OTHER
-        redirectLocation(result).value must startWith(controllers.routes.YourDirectDebitInstructionsController.onPageLoad().url)
+        redirectLocation(result).value mustBe legacyUrl
       }
     }
+
   }
 }

test/controllers/SetupDirectDebitPaymentControllerSpec.scala

@@ -27,6 +27,8 @@ import play.api.mvc.Call
 import play.api.test.FakeRequest
 import play.api.test.Helpers.*
 import services.{LockService, NationalDirectDebitService}
+import splitter.connectors.{AllowListConnector, FakeAllowListConnector}
+import splitter.controllers.{FakeIdentityIdentifierAction, IdentityIdentifierAction}
 import views.html.SetupDirectDebitPaymentView
 
 import java.time.Instant
@@ -35,7 +37,6 @@ import scala.concurrent.Future
 class SetupDirectDebitPaymentControllerSpec extends SpecBase {
 
   "SetupDirectDebitPayment Controller" - {
-
     val mockService = mock[LockService]
     val returnedDate = "2025-06-28T15:30:30Z"
 
@@ -60,7 +61,9 @@ class SetupDirectDebitPaymentControllerSpec extends SpecBase {
       val application = applicationBuilder(userAnswers = Some(emptyUserAnswers))
         .overrides(
           bind[NationalDirectDebitService].toInstance(mockRDSDatacacheService),
-          bind[LockService].toInstance(mockService)
+          bind[LockService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(true))
         )
         .build()
 
@@ -89,7 +92,9 @@ class SetupDirectDebitPaymentControllerSpec extends SpecBase {
       val application = applicationBuilder(userAnswers = Some(emptyUserAnswers))
         .overrides(
           bind[NationalDirectDebitService].toInstance(mockRDSDatacacheService),
-          bind[LockService].toInstance(mockService)
+          bind[LockService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(true))
         )
         .build()
 
@@ -118,7 +123,9 @@ class SetupDirectDebitPaymentControllerSpec extends SpecBase {
     "must return See Other and redirect for a GET if the user is locked but not verified" in {
       val application = applicationBuilder(userAnswers = Some(emptyUserAnswers))
         .overrides(
-          bind[LockService].toInstance(mockService)
+          bind[LockService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(true))
         )
         .build()
 
@@ -139,7 +146,9 @@ class SetupDirectDebitPaymentControllerSpec extends SpecBase {
     "must return See Other and redirect for a GET if the user is locked and verified" in {
       val application = applicationBuilder(userAnswers = Some(emptyUserAnswers))
         .overrides(
-          bind[LockService].toInstance(mockService)
+          bind[LockService].toInstance(mockService),
+          bind[IdentityIdentifierAction].to[FakeIdentityIdentifierAction],
+          bind[AllowListConnector].toInstance(FakeAllowListConnector(true))
         )
         .build()