fix(connector): [WORLDPAYWPG] fix PSync/RSync response parsing

[pixincreate]

Stacked on #2122. Base is feat/worldpayxml-wallet-decrypt-recurring; retarget to main once that merges.

The bug

PaymentService/Get (PSync) and RefundService/Get (RSync) returned RESPONSE_HANDLING_FAILED for every worldpayxml order — including plain card orders with no token, so this is independent of the recurring work in #2122 and predates it.

The sync body was deserialized directly into #[serde(untagged)] WorldpayxmlTransactionResponse. Untagged forces serde's deserialize_any, whose buffered value loses XML sequence and text semantics, so the Payment variant could never match any payload:

• balance: Option<Vec<_>> — a single <balance> buffers as a map, not a 1-element sequence.
• <lastEvent>CAPTURED</lastEvent> buffers as {"$text": "CAPTURED"}, which a unit-variant enum cannot be built from.

WorldpayxmlWebhookResponse, whose fields were all Option, then matched unconditionally — it matches literally any input, including unrelated XML. Every real parse error was silently swallowed and resurfaced as a generic failure at transformers.rs:1699, naming neither the failing type nor the field.

Proven in a standalone repro on the same quick-xml version: even the Authorize response that parses fine today resolves to the Webhook variant when routed through that enum. Authorize/Capture/Void/Refund work only because they are typed directly.

The fix

Stop routing XML through an untagged enum. WorldpayxmlTransactionResponse no longer derives Deserialize; a hand-written impl parses a concrete, element-driven body, wraps a <paymentService> reply into Payment manually, and only then falls back to the order-notification body. Concrete type first, enum as a manually-constructed carrier, no deserialize_any anywhere.

WorldpayxmlWebhookResponse gains a required OrderCode and a typed PaymentStatus — the all-Option shape is what made it match everything.

Response hardening, folded in

• LastEvent: added Settled, SentForAuthorisation, SentForFastRefund, RefundRequested, RefundedByMerchant, QueryRequired, CancelReceived, RefundReceived, plus #[serde(other)] Unknown. Without this PSync would have broken again the moment an order settled.
• Status mappers take previous_status and have an explicit Unknown arm that logs a warning and retains the prior status instead of erroring or assuming a terminal state.
• Previously-mandatory response fields wrapped in Option (AuthorisationId.@id, ResultCode.@description, Balance.@accountType/amount, PaymentMethodDetail.card, CardResponse.@type).

Expired was kept even though the reference implementation lacks it — dropping it would silently reroute a real EXPIRED event into Unknown/retain-previous, a behaviour regression.

payout_connectors/worldpayxml/transformers.rs is touched only because its status mapper matches the same shared enum and would not otherwise compile.

parse_last_event is removed entirely — with WorldpayxmlLastEvent now deserialized as a typed field, the helper is dead code. (#2122 fixes an unsafe JSON interpolation in it for the interim.)

Testing

Verified against the Worldpay sandbox. Clippy warning-free, no unwrap/expect, no suppressions, no test files.

Check	Before	After
Authorize → PSync	RESPONSE_HANDLING_FAILED	CHARGED, amount returned
CIT order with <token> → PSync	RESPONSE_HANDLING_FAILED	CHARGED
Refund → RSync	RESPONSE_HANDLING_FAILED	REFUND_PENDING (correct — Worldpay had not yet reflected it)
Parent-branch Authorize / SetupRecurring / MIT Charge	pass	pass — no regression

The payload that used to fail now parses, including the balance array and <lastEvent> that broke deserialize_any:

<orderStatus orderCode="..."><payment>
  <lastEvent>CAPTURED</lastEvent><AuthorisationId id="..."/>
  <paymentMethodDetail><card type="creditcard"/></paymentMethodDetail>
  <balance accountType="IN_PROCESS_CAPTURED"><amount value="1000" currencyCode="GBP" exponent="2"/></balance>
</payment></orderStatus>

An early PSync on a not-yet-available order returned Worldpay's <error code="5"> shape and correctly yielded PENDING rather than a hard failure.

🤖 Generated with Claude Code