feat: offer non-travelling applicant choice only on selected travels

src/Controller/Booking/Create/Step2Controller.php

@@ -83,6 +83,12 @@ class Step2Controller extends AbstractBookingCreateController
 
         $this->ensureCorrectNumberOfParticipants($bookingCreateDto);
 
+        // A session can still hold a split for a travel date that does not offer the choice.
+        if (false === $bookingCreateDto->applicantTravels
+            && false === $bookingCreateDto->travel->allowsNonTravellingApplicant()) {
+            $bookingCreateDto->restoreTravellingApplicant();
+        }
+
         // The account's own data belongs to whoever is the applicant: participant[0] normally,
         // and the separate applicant record when they do not travel along.
         $user = $this->getUser();

src/Controller/Booking/Create/Step2ParticipantController.php

@@ -139,6 +139,8 @@ class Step2ParticipantController extends AbstractController
      * Toggling on moves participant[0]'s personal data into the applicant record and leaves
      * behind a blank traveller that keeps only its index and room assignment: the services were
      * derived from an age that no longer applies. Toggling off moves it back.
+     *
+     * Only offered where the travel date allows it; elsewhere the request changes nothing.
      */
     #[Route(
         path: '/bookings/create/applicant-toggle',
@@ -153,6 +155,10 @@ class Step2ParticipantController extends AbstractController
         }
         $bookingDto = $result;
 
+        if (false === $bookingDto->travel->allowsNonTravellingApplicant()) {
+            return $this->htmxRedirect($request, $this->generateUrl('app_booking_create_step_2'));
+        }
+
         $this->travelDataService->enrichWithFreshAvailabilities($bookingDto->travel);
 
         // Captured before handleRequest(), which binds the new choice straight onto the DTO.
@@ -176,13 +182,7 @@ class Step2ParticipantController extends AbstractController
                 $bookingDto->participants[0] = $this->participantFormSupportService
                     ->createBlankTravellerFrom($bookingDto->applicant);
             } else {
-                $restored = $bookingDto->applicant;
-                if (null !== $restored) {
-                    $restored->index = 0;
-                    $restored->assignedRoomId = $bookingDto->participants[0]->assignedRoomId;
-                    $bookingDto->participants[0] = $restored;
-                }
-                $bookingDto->applicant = null;
+                $bookingDto->restoreTravellingApplicant();
             }
 
             // Family insurance is not offered on a split booking, so a choice already made on
@@ -221,7 +221,7 @@ class Step2ParticipantController extends AbstractController
         }
         $bookingDto = $result;
 
-        if (true === $bookingDto->applicantTravels) {
+        if (true === $bookingDto->applicantTravels || false === $bookingDto->travel->allowsNonTravellingApplicant()) {
             return $this->redirectToRoute('app_booking_create_step_2');
         }