feat: functionality to determine family status of a booking

src/Form/Model/BookingCreateDto.php

@@ -51,6 +51,40 @@ class BookingCreateDto implements BookingDtoInterface
         return $this->participants[$index] ?? null;
     }
 
+    /**
+     * Determines if this is a family booking based on participant age distribution.
+     *
+     * A family booking is defined as:
+     * - 1-2 participants aged 18 or older (adults)
+     * - At least 1 participant aged 20 or younger (young people/children)
+     *
+     * @return bool True if this qualifies as a family booking
+     */
+    public function isFamilyBooking(): bool
+    {
+        $adults = 0;        // Count of participants >= 18 years
+        $youngPeople = 0;   // Count of participants <= 20 years
+
+        foreach ($this->participants as $participant) {
+            $age = $participant->getAge();
+
+            if (null === $age) {
+                continue; // Skip participants without birth date
+            }
+
+            if ($age >= 18) {
+                ++$adults;
+            }
+
+            if ($age <= 20) {
+                ++$youngPeople;
+            }
+        }
+
+        // Check family booking criteria
+        return ($adults >= 1 && $adults <= 2) && ($youngPeople >= 1);
+    }
+
     #[Assert\Callback(callback: 'validateRoomSelection', groups: ['booking_create_step_1'])]
     public function validateRoomSelection(ExecutionContextInterface $context): void
     {

src/Form/Model/ParticipantDto.php

@@ -106,4 +106,23 @@ class ParticipantDto
     {
         return 'O' === $this->status;
     }
+
+    /**
+     * Calculates the participant's current age in complete years.
+     *
+     * Uses the same logic as existing age evaluators in the system
+     * for consistency across age-related calculations.
+     *
+     * @return int|null The calculated age in complete years, or null if no birth date
+     */
+    public function getAge(): ?int
+    {
+        if (null === $this->dateOfBirth) {
+            return null;
+        }
+
+        $today = new \DateTimeImmutable();
+
+        return $this->dateOfBirth->diff($today)->y;
+    }
 }