feat: voucher purchase flow

src/BusProNet/Model/VoucherSaleResponse.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\BusProNet\Model;
+
+/**
+ * A GUTSCHEINBUCHUNG response that is not a HINWEIS.
+ *
+ * The dry run (buchungsart Anfrage) answers <buchung>möglich</buchung> and nothing else, so every
+ * other field is only set by the actual purchase (buchungsart Buchung, <buchung>erfolgt</buchung>).
+ *
+ * The redemption code is deliberately not exposed to the customer before payment: BusPro mails the
+ * voucher itself once the transfer has arrived.
+ */
+final readonly class VoucherSaleResponse
+{
+    public const string SALE_POSSIBLE = 'möglich';
+    public const string SALE_PROCESSED = 'erfolgt';
+
+    public function __construct(
+        public string $status,
+        public ?int $voucherId = null,
+        public ?string $voucherNumber = null,
+        public ?string $redemptionCode = null,
+        public ?float $price = null,
+        public ?string $invoiceNumber = null,
+        public ?string $email = null,
+    ) {
+    }
+
+    public function isInquiryValid(): bool
+    {
+        return self::SALE_POSSIBLE === $this->status;
+    }
+
+    public function isSaleSuccessful(): bool
+    {
+        return self::SALE_PROCESSED === $this->status;
+    }
+}