feat: readonly room selection for single room types

src/Form/Service/Condition/SingleRoomTypeCondition.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Service\Condition;
+
+use App\Form\Model\BookingDto;
+use App\Form\Service\Contract\FieldConditionInterface;
+
+/**
+ * Condition that evaluates whether only a single room type is selected in the booking.
+ *
+ * This condition checks if exactly one room type has been selected with a positive quantity
+ * in the booking's room selections. When only one room type is available, the room assignment
+ * dropdown becomes unnecessary and can be made readonly to improve UX.
+ */
+class SingleRoomTypeCondition implements FieldConditionInterface
+{
+    /**
+     * Evaluates whether exactly one room type is selected in the booking.
+     *
+     * Counts the number of room types that have been selected with a quantity greater than zero.
+     * Returns true when exactly one room type is selected, false otherwise.
+     *
+     * @param BookingDto           $bookingDto       The current booking data (create or edit)
+     * @param int                  $participantIndex The index of the participant being evaluated
+     * @param array<string, mixed> $formData         Current form data for condition evaluation
+     *
+     * @return bool True if exactly one room type is selected, false otherwise
+     */
+    public function evaluate(BookingDto $bookingDto, int $participantIndex, array $formData): bool
+    {
+        $selectedRoomCount = 0;
+
+        foreach ($bookingDto->roomSelections as $roomSelection) {
+            if (null !== $roomSelection->quantity && $roomSelection->quantity > 0) {
+                ++$selectedRoomCount;
+            }
+        }
+
+        return 1 === $selectedRoomCount;
+    }
+
+    /**
+     * Returns field names that trigger re-evaluation of this condition.
+     *
+     * This condition depends on booking-level room selection data, not participant fields.
+     * Room selections are determined in step 1 and remain static during participant editing,
+     * so no participant-level field dependencies are needed.
+     *
+     * @return string[] Empty array (no participant-level dependencies)
+     */
+    public function getDependentFields(): array
+    {
+        return [];
+    }
+
+    /**
+     * Returns a human-readable description of this condition.
+     *
+     * @return string A brief description of the condition logic
+     */
+    public function getDescription(): string
+    {
+        return 'Field readonly when exactly one room type is selected';
+    }
+}

src/Form/Service/CreateFieldStateProvider.php

@@ -15,6 +15,7 @@ use App\Form\Service\Condition\FieldValueCondition;
 use App\Form\Service\Condition\RentalSelectionCondition;
 use App\Form\Service\Condition\RoomSelectionCondition;
 use App\Form\Service\Condition\ServiceSubTypeCondition;
+use App\Form\Service\Condition\SingleRoomTypeCondition;
 use App\Form\Service\Condition\SkiPassSelectionCondition;
 use App\Service\ParticipantEligibilityService;
 
@@ -204,6 +205,11 @@ class CreateFieldStateProvider extends AbstractFieldStateProvider
             'required' => new ApplicantCondition(),
         ];
 
+        // Make assignedRoomId readonly when only one room type is selected
+        $this->fieldStateConditions['assignedRoomId'] = [
+            'readonly' => new SingleRoomTypeCondition(),
+        ];
+
         // Example field state conditions would be registered here
         // For demonstration purposes, here are some example patterns: