feat: extract booking participant count service

docs/service-simplification-plan.md

@@ -18,7 +18,7 @@ The emphasis is not on deleting services for its own sake. The emphasis is on:
 The codebase is already in a better place than it was at the start of the refactor, but a few services still carry more than one responsibility:
 
 - `BookingService` no longer owns session lifecycle, baseline snapshot handling, return URL management, or room grouping. That work now lives in `BookingSessionService` and `BookingRoomSelectionService`, which keeps the booking orchestration boundary narrower.
-- `BookingService` still covers hydration, booking bootstrap, participant counting for participant auto-fill, service preselection, and booking status rules.
+- `BookingService` still covers hydration, booking bootstrap, service preselection, and booking status rules.
 - `BookingPriceCalculatorService` is focused on pricing, but it still sits close to display-oriented behavior in adjacent code paths.
 - `TravelDataService` remains broad and is likely the next larger boundary after booking orchestration is reduced.
 
@@ -104,7 +104,7 @@ Likely directions, only if justified later:
 |------|--------|-------|
 | Participant card DTO cleanup | Done | Card data now uses typed DTOs instead of nested array payloads |
 | Room label formatting cleanup | Done | Pricing labels now have a dedicated presentation helper |
-| Booking service split | In progress | Session lifecycle, baseline snapshot, return URL handling, and room grouping moved out of `BookingService` |
+| Booking service split | In progress | Session lifecycle, baseline snapshot, return URL handling, room grouping, and participant count shaping moved out of `BookingService` |
 | Pricing service review | Pending | Keep focused on calculation, not rendering |
 | Travel data service review | Pending | Broad boundary, likely later pass |
 | Participant field registry review | Deferred | Real orchestration boundary, intentionally left alone for now |

src/Controller/Booking/Create/Step2Controller.php

@@ -9,6 +9,7 @@ use App\Controller\Booking\Traits\BookingExceptionHandlerTrait;
 use App\Form\BookingCreateStep2Type;
 use App\Form\Model\BookingDto;
 use App\Service\BookingService;
+use App\Service\BookingParticipantCountService;
 use App\Service\BookingSessionService;
 use App\Service\BookingSummaryDataService;
 use App\Service\ParticipantCardDataService;
@@ -33,6 +34,7 @@ class Step2Controller extends AbstractController
 
     public function __construct(
         private readonly BookingService $bookingService,
+        private readonly BookingParticipantCountService $participantCountService,
         private readonly BookingSessionService $bookingSessionService,
         private readonly BookingSummaryDataService $summaryDataService,
         private readonly TravelDataService $travelDataService,
@@ -64,7 +66,7 @@ class Step2Controller extends AbstractController
         $this->travelDataService->enrichWithFreshAvailabilities($bookingCreateDto->travel);
 
         // Ensure correct number of participants with prepopulation callback
-        $this->bookingService->ensureCorrectNumberOfParticipants(
+        $this->participantCountService->ensureCorrectNumberOfParticipants(
             $bookingCreateDto,
             $this->getUser(),
             fn ($user, $participant) => $this->prepopulationService->prepopulateApplicantFromUser($user, $participant)

src/Service/BookingParticipantCountService.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+use App\BusProNet\Model\Travel;
+use App\Form\Model\BookingDto;
+use App\Form\Model\ParticipantDto;
+use Symfony\Component\Security\Core\User\UserInterface;
+
+/**
+ * Keeps participant-count shaping separate from booking orchestration.
+ */
+class BookingParticipantCountService
+{
+    /**
+     * Ensures the booking DTO has the expected number of participant objects.
+     *
+     * @param callable|null $prepopulateCallback fn(UserInterface, ParticipantDto): ParticipantDto
+     */
+    public function ensureCorrectNumberOfParticipants(
+        BookingDto $bookingDto,
+        ?UserInterface $user = null,
+        ?callable $prepopulateCallback = null,
+    ): void {
+        $participantsCount = $this->calculateParticipantsCount($bookingDto->roomSelections, $bookingDto->travel);
+
+        $existingParticipants = $bookingDto->participants;
+        $bookingDto->participants = [];
+
+        for ($i = 0; $i < $participantsCount; ++$i) {
+            $participant = $existingParticipants[$i] ?? new ParticipantDto();
+            $participant->index = $i;
+
+            // Prepopulate applicant from authenticated user (index 0 only)
+            if (0 === $i && null !== $user && null !== $prepopulateCallback && $this->shouldPrepopulate($participant)) {
+                $participant = $prepopulateCallback($user, $participant);
+            }
+
+            $bookingDto->participants[$i] = $participant;
+        }
+    }
+
+    /**
+     * Calculates the total number of participants based on room selections.
+     *
+     * Multiplies each room's minimum occupancy (minPax) by the selected quantity
+     * to determine the total number of participants required for the booking.
+     *
+     * @param array  $roomSelections Array of room selection DTOs
+     * @param Travel $travelData     Travel data containing room information
+     */
+    private function calculateParticipantsCount(array $roomSelections, Travel $travelData): int
+    {
+        $participantsCount = 0;
+        $rooms = $travelData->getAvailableRooms();
+
+        foreach ($roomSelections as $roomSelection) {
+            $room = $rooms[$roomSelection->id];
+            $participantsCount += $room->minPax * $roomSelection->quantity;
+        }
+
+        return $participantsCount;
+    }
+
+    /**
+     * Only prepopulate if the participant is fresh.
+     */
+    private function shouldPrepopulate(ParticipantDto $participant): bool
+    {
+        return null === $participant->firstName || '' === $participant->firstName;
+    }
+}

src/Service/BookingService.php

@@ -660,60 +660,4 @@ class BookingService
      * @param \Symfony\Component\Security\Core\User\UserInterface|null $user                Optional authenticated user for prepopulation
      * @param callable|null                                            $prepopulateCallback Callback to prepopulate applicant: fn(UserInterface, ParticipantDto): ParticipantDto
      */
-    public function ensureCorrectNumberOfParticipants(
-        BookingDto $bookingDto,
-        ?\Symfony\Component\Security\Core\User\UserInterface $user = null,
-        ?callable $prepopulateCallback = null,
-    ): void {
-        $participantsCount = $this->calculateParticipantsCount($bookingDto->roomSelections, $bookingDto->travel);
-
-        $existingParticipants = $bookingDto->participants;
-        $bookingDto->participants = [];
-
-        for ($i = 0; $i < $participantsCount; ++$i) {
-            $participant = $existingParticipants[$i] ?? new ParticipantDto();
-            $participant->index = $i;
-
-            // Prepopulate applicant from authenticated user (index 0 only)
-            if (0 === $i && null !== $user && null !== $prepopulateCallback && $this->shouldPrepopulate($participant)) {
-                $participant = $prepopulateCallback($user, $participant);
-            }
-
-            $bookingDto->participants[$i] = $participant;
-        }
-    }
-
-    /**
-     * Determines if a participant should be prepopulated.
-     *
-     * Only prepopulates if the participant is "fresh" (no name set yet).
-     */
-    private function shouldPrepopulate(ParticipantDto $participant): bool
-    {
-        return null === $participant->firstName || '' === $participant->firstName;
-    }
-
-    /**
-     * Calculates the total number of participants based on room selections.
-     *
-     * Multiplies each room's minimum occupancy (minPax) by the selected quantity
-     * to determine the total number of participants required for the booking.
-     *
-     * @param array  $roomSelections Array of RoomSelectionDto objects
-     * @param Travel $travelData     Travel data containing room information
-     *
-     * @return int Total number of participants required
-     */
-    private function calculateParticipantsCount(array $roomSelections, Travel $travelData): int
-    {
-        $participantsCount = 0;
-        $rooms = $travelData->getAvailableRooms();
-
-        foreach ($roomSelections as $roomSelection) {
-            $room = $rooms[$roomSelection->id];
-            $participantsCount += $room->minPax * $roomSelection->quantity;
-        }
-
-        return $participantsCount;
-    }
 }

tests/Service/BookingParticipantCountServiceTest.php

@@ -0,0 +1,103 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Service;
+
+use App\BusProNet\Model\Room;
+use App\BusProNet\Model\Travel;
+use App\BusProNet\Constants;
+use App\Form\Model\BookingDto;
+use App\Form\Model\ParticipantDto;
+use App\Form\Model\RoomSelectionDto;
+use App\Service\BookingParticipantCountService;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Security\Core\User\UserInterface;
+
+class BookingParticipantCountServiceTest extends TestCase
+{
+    private BookingParticipantCountService $service;
+
+    protected function setUp(): void
+    {
+        $this->service = new BookingParticipantCountService();
+    }
+
+    public function testEnsureCorrectNumberOfParticipantsExpandsToCalculatedCount(): void
+    {
+        $travel = $this->createTravel([
+            1 => 2,
+            2 => 3,
+        ]);
+
+        $bookingDto = new BookingDto($travel, 123);
+        $bookingDto->roomSelections = [
+            $this->createRoomSelection(1, 1),
+            $this->createRoomSelection(2, 2),
+        ];
+        $bookingDto->participants = [new ParticipantDto()];
+
+        $this->service->ensureCorrectNumberOfParticipants($bookingDto);
+
+        $this->assertCount(8, $bookingDto->participants);
+        $this->assertSame(0, $bookingDto->participants[0]->index);
+        $this->assertSame(7, $bookingDto->participants[7]->index);
+    }
+
+    public function testEnsureCorrectNumberOfParticipantsPrepopulatesFreshApplicant(): void
+    {
+        $travel = $this->createTravel([1 => 2]);
+        $bookingDto = new BookingDto($travel, 123);
+        $bookingDto->roomSelections = [$this->createRoomSelection(1, 1)];
+        $bookingDto->participants = [new ParticipantDto()];
+
+        $user = $this->createMock(UserInterface::class);
+        $callbackCalled = false;
+
+        $this->service->ensureCorrectNumberOfParticipants(
+            $bookingDto,
+            $user,
+            function (UserInterface $userArg, ParticipantDto $participant) use (&$callbackCalled): ParticipantDto {
+                $callbackCalled = true;
+                $participant->firstName = 'Alex';
+
+                return $participant;
+            }
+        );
+
+        $this->assertTrue($callbackCalled);
+        $this->assertSame('Alex', $bookingDto->participants[0]->firstName);
+    }
+
+    private function createTravel(array $roomCapacities): Travel
+    {
+        $travel = new Travel();
+        $travel->dateFrom = new \DateTimeImmutable('2030-01-01');
+        $travel->dateTo = new \DateTimeImmutable('2030-01-06');
+
+        $rooms = [];
+        foreach ($roomCapacities as $id => $minPax) {
+            $room = new Room();
+            $room->id = $id;
+            $room->label = 'Room '.$id;
+            $room->minPax = $minPax;
+            $room->maxPax = $minPax + 1;
+            $room->available = 5;
+            $room->status = Constants::STATUS_AVAILABLE;
+            $rooms[$id] = $room;
+        }
+
+        $travel->rooms = $rooms;
+
+        return $travel;
+    }
+
+    private function createRoomSelection(int $id, int $quantity): RoomSelectionDto
+    {
+        $selection = new RoomSelectionDto();
+        $selection->id = $id;
+        $selection->quantity = $quantity;
+
+        return $selection;
+    }
+}