bank tranfer fix

server/implementations/Catcrafts.Server-Bunq.cpp

@@ -192,6 +192,37 @@ std::vector<BankCredit> ParseBunqPayments(std::string_view json) {
     return out;
 }
 
+std::optional<BankCredit> ParseBunqCallback(std::string_view json) {
+    const auto doc = Json::Parse(json);
+    if (!doc || !doc->IsObject()) return std::nullopt;
+    const Json::Value* note = doc->Find("NotificationUrl");
+    if (!note || !note->IsObject()) return std::nullopt;
+    const Json::Value* object = note->Find("object");
+    if (!object || !object->IsObject()) return std::nullopt;
+    const Json::Value* p = object->Find("Payment");
+    if (!p || !p->IsObject()) return std::nullopt;
+
+    const Json::Value* amount = p->Find("amount");
+    if (!amount || !amount->IsObject()) return std::nullopt;
+    // Only euro can pay a euro order; see ParseBunqPayments for why a
+    // foreign-currency credit is skipped rather than counted at face value.
+    if (amount->Str("currency") != "EUR") return std::nullopt;
+    const std::optional<std::int64_t> minor =
+        ParseSignedAmountToMinor(amount->Str("value"));
+    if (!minor) return std::nullopt;
+
+    BankCredit c;
+    c.id = std::format("{}", p->Int("id"));
+    c.reference = std::string(p->Str("description"));
+    c.amountMinor = *minor;
+    c.method = std::string(BunqMethodFor(p->Str("type")));
+    // An id is what deduplication rests on. A callback without one cannot be
+    // deduplicated, so accepting it would let a retry credit the same money
+    // twice — refuse instead.
+    if (c.id.empty() || c.id == "0") return std::nullopt;
+    return c;
+}
+
 namespace {
 
 class BunqCreditSource final : public CreditSource {