feat: inform user about automatic reassignments or reset selections

src/Controller/Booking/CreateStep2Controller.php

@@ -131,6 +131,9 @@ class CreateStep2Controller extends AbstractController
 
         $this->bookingService->saveBookingCreateDto($request, $bookingCreateDto);
 
+        // Collect notifications from all participants
+        $notifications = $this->collectParticipantNotifications($bookingCreateDto);
+
         $summary = $this->bookingService->getRoomSummaryAndParticipantCount($bookingCreateDto);
         $roomAssignmentCounts = $this->bookingService->getRoomAssignmentCounts($bookingCreateDto);
         $availableRooms = $bookingCreateDto->travel->getAvailableRooms();
@@ -139,7 +142,7 @@ class CreateStep2Controller extends AbstractController
 
         // The DTO is now updated with the latest selection and submitted data has been cleaned.
         // We can now render the blocks with the fresh data.
-        return $this->htmxOobResponse(
+        $response = $this->htmxOobResponse(
             'booking/create_step_2.html.twig',
             ['participants_form', 'booking_summary'],
             [
@@ -152,6 +155,15 @@ class CreateStep2Controller extends AbstractController
                 'groupedSelectedRooms' => $groupedSelectedRooms,
             ]
         );
+
+        // Add notifications to HTMX trigger header if any exist
+        if ([] !== $notifications) {
+            $response->headers->set('HX-Trigger', json_encode([
+                'showNotifications' => ['notifications' => $notifications],
+            ]));
+        }
+
+        return $response;
     }
 
     /**
@@ -233,4 +245,28 @@ class CreateStep2Controller extends AbstractController
             $this->roomAssignmentService->assignParticipantsToRooms($bookingCreateDto);
         }
     }
+
+    /**
+     * Collects all notifications from participants and clears them.
+     *
+     * @param BookingCreateDto $bookingCreateDto The booking DTO containing participants
+     *
+     * @return array<array{type: string, message: string}> Array of notification messages
+     */
+    private function collectParticipantNotifications(BookingCreateDto $bookingCreateDto): array
+    {
+        $notifications = [];
+
+        foreach ($bookingCreateDto->participants as $participant) {
+            if ([] !== $participant->notifications) {
+                foreach ($participant->notifications as $notification) {
+                    $notifications[] = $notification;
+                }
+                // Clear notifications after collection
+                $participant->notifications = [];
+            }
+        }
+
+        return $notifications;
+    }
 }