more cart

pkg/cart/recovery/recovery.go

@@ -0,0 +1,49 @@
+// Package recovery is the v0 abandoned-cart-recovery seam.
+//
+// The contract is intentionally narrow: a Scanner finds candidates whose last
+// mutation is within an "abandoned" window and that have BOTH an attachable
+// contact (email and/or push tokens) and items in the cart, then hands them
+// to a Notifier. The Notifier decides what to do — for now a logging shim.
+//
+// The seam intentionally avoids:
+//
+//   - Email/push-token delivery (lives in the notifier impl).
+//   - Idempotency tracking ("did we already notify?"). v0: scanner windows
+//     are sized so a cart falls in once per detection threshold. Real
+//     idempotency is the next pass — see suggest_followups / plan-commerce-
+//     maturity C3.
+//   - Cross-pod coordination. Each cart pod owns its own shard of event logs
+//     (replicated read cache, no leader), so per-pod scanning is correct.
+//     A future AMQP fan-out of `cart.recovery.candidate` would let a single
+//     dedicated notifier consume instead — out of scope here.
+package recovery
+
+import (
+	"context"
+
+	"git.k6n.net/mats/go-cart-actor/pkg/cart"
+)
+
+// RecoveryCandidate is the projectable "we'd remind this shopper" shape.
+// Fields surface just enough for a future email template / push payload; the
+// underlying grain carries everything else.
+type RecoveryCandidate struct {
+	CartID      cart.CartId
+	UserID      string // empty if the cart hasn't been linked to a profile
+	Email       string
+	PushTokens  []cart.PushToken
+	ItemCount   int
+	TotalIncVat int64 // minor units (money.Cents == int64)
+	Currency    string
+	// LastChange is best-effort: the scanner reads the event-log file's
+	// modification time. A pending notifier shouldn't use it as the canonical
+	// "when was this cart touched?" wall clock — see cart.LastChange.
+	LastChangeUnix int64
+}
+
+// Notifier is the seam a real email/push implementation plugs into. The
+// LoggingNotifier is the v0 default. The cart service ships the seam even
+// before a real send exists so call-sites and tracking can be wired once.
+type Notifier interface {
+	NotifyAbandoned(ctx context.Context, c RecoveryCandidate) error
+}