Money-safety idempotency fixes (external review bugs 1-3):
- processChargeGroup: aggregated refund key now hashes the sorted pending-row
set (chargeID-square-agg-<sha256 suffix>) so a changed group can never mark
a new row completed against an old smaller refund; >45-char chargeIDs use a
hashed prefix instead of verbatim truncation (which would collide charges on
Square's global key dedup). Same-set crash-retry keeps Square's dedup.
- CreateTerminalPayment saved_card: two-tier idempotency key — client-supplied
per-attempt UUID preferred (distinct identical charges no longer collapse),
deterministic booking+type+amount+card fallback for no-key retry safety.
PaymentModal sends a per-charge UUID cleared after success.
- ensureRefundKey: legacy NULL-key manual refunds persist a generated key to
the row BEFORE the Square call (race-safe AND idempotency_key IS NULL guard),
so a lost-response retry reuses the key and never double-refunds. Wired into
resumeManualPendingRefund and the sweep's manual-retry loop.
Classification + money-safety hardening:
- till.go/sweep.go: structured square.ErrorCode/IsNotFound are authoritative
when present; message-substring matching only for non-structured errors
(dev mock, client-side status errors). Fixes fragile string-matching driving
sweep retries and gift-card clawbacks.
- SaveCardForUser: ON CONFLICT (user_id, square_card_id) DO NOTHING + re-select
(was a latent UNIQUE-violation 500 on save-card retry).
- CreateBookingPayment: partial payments re-validated against remaining balance
inside the advisory lock (closes concurrent-overpayment race).
- InvalidateSquareCustomerCache on GDPR erasure paths (account.go,
time-blockers.go stale-guest anonymization).
- GetUserGiftCardBalanceAdmin: in-handler admin check (defense-in-depth).
- getCheckoutHTTP: warn on multi-payment checkouts instead of dropping
payments[1:].
- Cash/giftcard terminal branch: removed dead idempotency SELECT, "tip-" ->
"till-" prefix.
- UserPaymentModal: removed vestigial polling state; proper interval cleanup.
- account/+page.svelte: gift-card redeem dialog links /terms.
- nginx CSP: allow *.squarecdn.com and js.squareup.com so the Square Web
Payments SDK + card iframe can tokenize behind the proxy.
Tests: +8 regression tests covering changed-set refund keys, legacy NULL-key
single-refund, saved-card client-key dedup/no-dedup, concurrent partials, and
cache invalidation. Full suite + race detector clean via run-tests.sh lockfile.
Till sales and gift-card purchases now use uniqueChargeKey and resolveChargeSource/chargeFailureStatus instead of duplicated inline logic. The saved-card delete path logs the square_card_id through square.TokenPrefix so full ccof references never reach logs.
One-off new-card charges now pass the cnon: nonce directly as source_id (no card-on-file, no customer). Save-card charges forward customer_id; legacy saved cards lazily provision a Square customer before charging (EnsureSquareCustomerForSavedCard). Terminal checkouts insert the terminal_checkouts row FIRST with a provisional tmp- id, then update with the real checkout_id, closing the crash window. GetDiscountPreviewHandler gains the fail-closed ownership check (IDOR). DeletePaymentMethod disables the card at Square before soft-delete. Sweep resolves provisional/tmp- terminal rows without a Square round-trip. GetCheckoutStatus rejects tmp- ids.
R1/R4: saved_card branch in CreateTerminalPayment now mirrors CreateTipPayment
- advisory lock (crussell:payment:<bookingID>) serializes concurrent double-clicks
- deterministic key bookingID-sc-type-amount-cardID (<=45 chars) so a lost-response
retry derives the same key and dedups instead of double-charging
- idempotency switch inside the lock: completed -> dedup, pending -> reuse with
pence amount-guard, failed -> clean 409
- success response includes card_brand/card_last4 (frontend already reads them)
R2: add 'failed' case to all four retry switches (tip, booking, gift card, till)
- a swept/definitively-rejected record returns 409 instead of 500-ing on the
idempotency_key UNIQUE constraint
R3: extend SweepStalePendingPayments to till_sales card rows
- sweeps pending till_sales (online_square/in_person_card) past Square's ~24h
key retention, closing the double-charge window for till sales
- swept rows logged with the same CRITICAL manual-reconciliation marker as the
refund sweep
Webhook fail-closed: reject 503 when SQUARE_WEBHOOK_SIGNATURE_KEY unset, 403 on
bad signature (was: skip verification in dev)
Refund status resolution: refunds now resolve by Square status
(COMPLETED/PENDING/FAILED/REJECTED) instead of assuming completed; real error
codes (REFUND_AMOUNT_INVALID, PAYMENT_NOT_REFUNDABLE, REFUND_ALREADY_PENDING)
added to the definitive/processed classification
HTTP client: CreateCard key truncated to <=45 chars, device_options always sent
(env SQUARE_TERMINAL_DEVICE_ID fallback), processing_fee reads amount_money,
ListCards cursor loop, refund keys hashed to <=45 chars
Other fixes: payment/till/gift-card advisory-lock + FOR UPDATE asymmetries,
GetPaymentByID NULL scans, loyalty redemption lock, card upsert on conflict,
mock ccof: prefix parity, IsValidSquareCheckoutID for real Square IDs,
isAdminRequest defense-in-depth on all 6 admin payment handlers, webhook
signature docs, M8/L5 debug markers removed
Docs: README/FC/TM/Overview updated (22 jobs, 20 CRITICAL sites, 23-section
GDPR export, sweep jobs, webhook fail-closed); P11 plan marks remaining items
(sandbox smoke test, M-8 customer_id, saved-card key dedup trade-off) as
deferred with rationale; gap backlog pruned of completed items
Refund idempotency (P2):
- RefundRequest gains an optional client idempotency_key: two DISTINCT equal
partial refunds of one payment no longer collide on the amount-derived key
(the second was silently swallowed as a dedup)
- Extract resumeManualPendingRefund: resumes a pending refund with the row's
OWN stored key, so Square's key dedup returns the original refund if the
prior attempt completed — never issues a second
- (payment, amount) pending fallback: when the exact-key lookup misses (admin
reopened the modal, new UUID), resume the matching pending row instead of
creating a second pending row the sweep would double-process
- 409 in-flight guard: if a pending refund exists for the payment but no
same-amount row matches, reject a different-amount refund (money state at
Square is unknown — no new refund is safe until it resolves)
- Frontend (EditBookingModal): UUID per refund attempt, reused on retry,
mirroring the tip flow
Terminal completion (P3):
- GetCheckoutStatus serializes on pg_advisory_lock('crussell:terminal:' ||
SquarePayID) on a pinned connection — concurrent polls of the same checkout
can no longer both pass the dedup SELECT and race the UNIQUE constraint
Card-on-file / doc-only:
- Document why CreateCardOnFile is NOT rolled back on payment failure
(deterministic sha256 retry returns the same card; deletion breaks it)
- Document HasCompletedPayment's deliberate 'tip' exclusion
Regression tests:
- TestRefund_TwoEqualPartialRefunds_ClientKeyDisambiguates
- TestRefund_PendingResume_NewKeyAfterModalReopen (proves stored-key resume)
- TestRefund_PendingResume_DifferentAmountRejected (409 + no second row)
- TestRefund_GuardCountsPendingRefunds updated: 400 -> 409 (in-flight guard
fires first — strictly safer, blocks before any Square attempt)
- TestGetCheckoutStatus_ConcurrentPolls_SingleRecord (real two-goroutine race)
Refund system (Round 3 fixes + follow-up + alignment):
- Serialize cancellation refunds against the manual handler via
per-payment advisory locks taken before the prior-refunds read
(pg_advisory_xact_lock, ascending, same crussell:refund: key space)
- Aggregate pending cancellation refunds into ONE Square refund per
charge (stable charge-level -square-agg key); atomic group UPDATE
keeps crash-retry amounts identical for Square key-dedup
- Persist paymentID-square-amount idempotency keys on cancellation
refunds; scheduler reads the stored key (legacy fallback for old rows)
- Add sweep-pending-square-refunds cron (*/5, concurrency 1) with
refund_attempts cap; sweep retries stale manual pending refunds with
each row's own stored idempotency key
- Reconcile at Square (GET /v2/refunds ListPaymentRefunds) before every
terminal failed transition: tri-state result leaves rows pending on
reconcile error instead of false-failing; PAYMENT_ALREADY_REFUNDED
resolves to completed
- Move over-refund guard inside the lock, counting completed + pending
(excluding failed); ErrRefundDeclined distinguishes definitive vs
ambiguous outcomes
- forgiveFees now executes a real full refund (forceFullRefund override)
with admin_forgiven_fees reason threaded to Square
- Surface failed card refunds in the admin notification centre
(refund_failed enum, RETURNING-id pre-pass inserts, NOT EXISTS dedup)
- Dedup double-cancel refund inserts via ON CONFLICT (idempotency_key)
DO NOTHING without consuming refundRemaining
Frontend:
- Remove all raw-PAN card entry: zero card_number/card_cvc/new_card_token
in request bodies; gate new-card entry behind CardEntryUnavailable
notice + newCardDisabled prop across all 8 flows
- Delete hand-rolled CardInput.svelte; keep CardSelection saved-card UI
and CardEntryUnavailable fallback
- Update cancellation-policy page to in-person cash pickup wording
Tests:
- Rewrite the two amount-blind dedup tests to assert real money movement
(single call, aggregated amount, shared refund ID)
- Add coverage: manual refund vs cancellation serialization (concurrent
goroutines), reconcile error vs no-match branches, stale manual retry,
forgive-fees real refund row + reason, double-cancel dedup, mock refund
key dedup, ListPaymentRefunds filtering
- Fix time-dependent booking flakes with fixtures.NextWorkingDayAt
- 25/25 packages pass; -race clean on payments/square/db/jobs/bookings
P0 — float truncation: applied math.Round to all remaining int64(x*100)
sites (till penceAmount, refund over-refund guard, GetAlreadyRefundedAmount,
payment summary conversions). A £1.14 till sale previously charged 113p.
P0 — raw PAN stopped at the API edge:
- Deleted CardNumber/CardExpMonth/CardExpYear/CardCVC from TillSaleRequest
and CardNumber/Expiry/CVC from CreatePaymentMethodRequest. Both now accept
card_token (Square nonce) and return 400 when absent. PAN+CVV no longer
transit the application server (PCI-DSS SAQ-A scope).
- Deleted CreateCardOnFileRaw from the SquareClient interface and all
implementations (MockClient, ProdClient, devProdClient).
- Added idempotency_key column to refunds table (UNIQUE).
P0 — RefundPayment hardened: advisory lock on payment ID (prevents two
concurrent refunds passing the over-refund guard), pending-refund-record-
then-Square pattern (scheduler reprocesses on failure), same-key dedup.
P1 — till sale pending-retry now re-attempts the Square charge instead of
returning the stale 'pending' status (gift card was already funded in the
committed tx — silent money loss otherwise). Sale row reused, not duplicated.
P1 — idempotency key caching in frontend: BuyGiftCard and
UserPaymentModal/BookingFlow now cache the key per amount+card, regenerated
on change and cleared on success — matches the tip-flow pattern so a
lost-response retry dedups instead of double-charging.
P1 — CreateTerminalPayment cash/giftcard INSERTs now persist idempotency_key.
Key is unique per payment (booking+type+amount would wrongly dedup two
legitimate identical payments, e.g. two £50 cash receipts).
P1 — gift-card codes no longer logged (spendable credential; value+recipient
only).
Tests: till pending-retry re-attempt, refund same-key dedup, mock CreatePayment
idempotency dedup, CreatePaymentMethod nonce happy path + raw-PAN rejection,
till online_square card_token required/valid.
N1 (HIGH) — BuyGiftCard concurrent same-key retry could double-issue gift
cards (2× value for 1 charge). Added pg_advisory_lock on the idempotency key
(mirroring the tip pattern) acquired before the idempotency check, so
concurrent same-key retries serialize and only one executes gift-card
creation.
N2 — Amount-equality guards in both reuse branches (CreateTipPayment and
BuyGiftCard). A same-key retry with a different amount now returns 400
instead of silently mutating the pending record's books/VAT/refund caps.
N3 — test coverage:
- TestBuyGiftCard_RetryPending_ReattemptsCharge: pending record + same-key
retry re-attempts, reuses the record (count=1), completes, and issues the
gift card exactly once.
- TestCreateCheckoutHTTP_DeviceOptionsWireShape: httptest.Server asserts
device_id is under checkout.device_options (not top-level). Extracted
createCheckoutHTTPWithClient for injectable base URL.
- MockClient.CreatePayment now dedups on idempotency key (paymentByKey map),
matching real Square behaviour.
N4 — Corrected the savepoint comments in handlers.go and giftcards.go: the
savepoint only exists in the test harness; in production db.Conn.Begin is a
plain tx and the status UPDATE runs on a separate pooled connection. Commit
is a harmless no-op in prod but required in tests.
Bonus bug fixed: CheckIdempotencyByKey scanned NULL booking_id/gift_card_id
(gift-card purchases) into plain string, failing with 'cannot scan NULL'.
Now uses sql.NullString.
Docs: Technical Manual.md:53 and Feature Catalog.md (2.1, 2.5) corrected —
no longer claim Web Payments SDK is live; new-card entry is documented as
pending P11, saved-card flow works via ccof tokens, dev mock rejects raw PANs.
Restore processImage (images.go) and nonDepositPaymentType (handlers.go) with //nolint:unused — used in test files.
Fix 97 tx.Rollback defers to silently discard expected "tx is closed" error after commit.
Frontend: remove 44 unused shadcn-svelte files, 2 dead components, 9 stale npm deps, prune unused exports.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
errcheck: add proper error handling with slog.Error for tx.Rollback, key generation, and s3/dav operations. Add nolint comments for intentionally discarded DB scan errors and HTTP write errors.
unused: remove dead code (svcRow type, processImage, nonDepositPaymentType, generateSecureCode, colorBold, nGreen, nRed)
gosimple S1021: merge var declaration with assignment in manage.go
ineffassign: remove dead assignments in settings.go, till.go, images.go
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Refactor BuyGiftCard to insert pending payment before Square call with VAT applied. Add transaction wrapping to gift card handlers. Remove redundant Content-Type header sets. Migrate all time.Now() to clock.Now().
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Track voucher_type_at_purchase on gift card creation. Apply VAT at gift card purchase (SPV), at redemption (MPV). Use transaction-aware GetCardByIDQuerier for till saved card lookups. Apply VAT to all booking payments (split records, terminal, tip, checkout). Add TotalVATAmount and TotalNetAmount to PaymentSummary responses.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Simplify payment handlers by using bookings.total_amount computed column instead of inline UNION sub-queries calculating price totals from booking_services and booking_custom_services.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Replace direct *pgxpool.Pool usage with PoolProxy wrapper across the entire backend:
- db.DB renamed to db.Conn (*pgxpool.Pool -> *PoolProxy)
- JWT functions now accept context.Context instead of using context.Background()
- Handler DB calls route through PoolProxy for per-test transaction support
- Fixture/helper/testdb functions accept Querier interface for decoupling
- Query ordering fixed in bookings handlers: COUNT after data query to avoid pgx conn busy
- Time truncation fixed: time.Date instead of Truncate(24*time.Hour) for week start calc
- testmain_test.go files updated with SeedBaseline and NewPoolProxy
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Update booking create/confirm/progress/reserve handlers to support custom_service_ids and custom overrides. Add UNION ALL queries to include custom_services in booking detail, payment summary, scheduling availability, today dashboard, and customer relationship queries.
Ultraworked with Sisyphus (https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
- Added generic formatAndPreserveCursor() helper on frontend to track
and restore selection caret position during dynamic input sanitization
- Applied to all card inputs, gift card code inputs, and expiry inputs
- Added Luhn validation (isValidLuhn) for saved cards and gift cards
- Rebuilt payments test DB and got 100% green tests