feat: split booking between participants and applicant

addresses #869f2q1vu

src/Form/Service/ParticipantEmailFieldHandler.php

@@ -0,0 +1,102 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Service;
+
+use App\Form\Model\BookingDto;
+use App\Form\Model\ParticipantDto;
+use App\Form\Service\Abstract\AbstractParticipantFieldHandler;
+
+/**
+ * Handles the email field, pre-filling the applicant's address for under-16 participants.
+ *
+ * BusPro requires a Mail-Adresse for every participant once a room is present and rejects the
+ * step-3 Anfrage with 650 otherwise, children included. It does accept an address identical to
+ * the Anmelder's, so children inherit the applicant's rather than being asked for one they
+ * typically do not have. The value stays editable and stays mandatory.
+ *
+ * The copy only ever fills a blank, so an address somebody typed is never overwritten. A later
+ * correction to the applicant's own address therefore does not propagate to children who already
+ * inherited the previous one.
+ *
+ * Depends on dateOfBirth: whether a participant counts as a child is only known once their date
+ * of birth has been processed.
+ */
+class ParticipantEmailFieldHandler extends AbstractParticipantFieldHandler
+{
+    public function getFieldName(): string
+    {
+        return 'email';
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getDependencies(): array
+    {
+        return ['dateOfBirth'];
+    }
+
+    /**
+     * @param array<string, mixed> $submittedData    The submitted participant form data
+     * @param BookingDto           $bookingDto       The booking DTO to update (create or edit)
+     * @param int                  $participantIndex The index of the participant being processed
+     */
+    public function processField(array $submittedData, BookingDto $bookingDto, int $participantIndex): void
+    {
+        $participant = $this->getParticipant($bookingDto, $participantIndex);
+
+        if (false === $participant instanceof ParticipantDto) {
+            return;
+        }
+
+        $submitted = $this->getFieldValue($submittedData, $this->getFieldName());
+
+        if (true === is_string($submitted)) {
+            $participant->email = '' !== trim($submitted) ? trim($submitted) : null;
+        }
+
+        $this->applyApplicantEmail($bookingDto, $participant);
+    }
+
+    /**
+     * Copies the applicant's address onto a child who has none of their own.
+     */
+    public function applyApplicantEmail(BookingDto $bookingDto, ParticipantDto $participant): void
+    {
+        if (false === $participant->isChild()) {
+            return;
+        }
+
+        $applicantEmail = $this->resolveApplicantEmail($bookingDto);
+
+        if (null === $applicantEmail) {
+            return;
+        }
+
+        // The applicant themselves never inherits, and on an ordinary booking that is participant[0].
+        if (true === $participant->isApplicant() && true === $bookingDto->applicantTravels) {
+            return;
+        }
+
+        if (null === $participant->email || '' === trim($participant->email)) {
+            $participant->email = $applicantEmail;
+        }
+    }
+
+    private function resolveApplicantEmail(BookingDto $bookingDto): ?string
+    {
+        $applicant = $bookingDto->applicantTravels
+            ? ($bookingDto->participants[0] ?? null)
+            : $bookingDto->applicant;
+
+        $email = $applicant?->email;
+
+        if (null === $email || '' === trim($email)) {
+            return null;
+        }
+
+        return trim($email);
+    }
+}