order sagas

pkg/order/payment.go

@@ -0,0 +1,69 @@
+package order
+
+import (
+	"context"
+	"fmt"
+)
+
+// Authorization is the result of authorizing a payment with a provider.
+type Authorization struct {
+	Provider  string
+	Reference string
+	Amount    int64
+}
+
+// Capture is the result of capturing an authorization.
+type Capture struct {
+	Provider  string
+	Reference string
+	Amount    int64
+}
+
+// RefundResult is the result of refunding a captured payment.
+type RefundResult struct {
+	Provider  string
+	Reference string
+	Amount    int64
+}
+
+// PaymentProvider abstracts a payment processor. It mirrors the ShippingProvider
+// seam in go-shipping: one interface, interchangeable implementations. The order
+// flow actions (pkg/order/actions.go) call this; the grain only records facts.
+type PaymentProvider interface {
+	Name() string
+	Authorize(ctx context.Context, orderRef string, amount int64, currency string) (Authorization, error)
+	Capture(ctx context.Context, authRef string, amount int64) (Capture, error)
+	Refund(ctx context.Context, captureRef string, amount int64) (RefundResult, error)
+	Void(ctx context.Context, authRef string) error
+}
+
+// MockProvider is a deterministic, always-succeeding payment provider. It lets
+// an order be placed and paid end-to-end with no external dependency — the
+// simplest path to a captured order for local dev, demos and tests.
+type MockProvider struct{}
+
+func NewMockProvider() *MockProvider { return &MockProvider{} }
+
+var _ PaymentProvider = (*MockProvider)(nil)
+
+func (m *MockProvider) Name() string { return "mock" }
+
+func (m *MockProvider) Authorize(_ context.Context, orderRef string, amount int64, _ string) (Authorization, error) {
+	return Authorization{Provider: m.Name(), Reference: "mock-auth-" + orderRef, Amount: amount}, nil
+}
+
+func (m *MockProvider) Capture(_ context.Context, authRef string, amount int64) (Capture, error) {
+	if authRef == "" {
+		return Capture{}, fmt.Errorf("mock: capture requires an authorization reference")
+	}
+	return Capture{Provider: m.Name(), Reference: "mock-capture-" + authRef, Amount: amount}, nil
+}
+
+func (m *MockProvider) Refund(_ context.Context, captureRef string, amount int64) (RefundResult, error) {
+	if captureRef == "" {
+		return RefundResult{}, fmt.Errorf("mock: refund requires a capture reference")
+	}
+	return RefundResult{Provider: m.Name(), Reference: "mock-refund-" + captureRef, Amount: amount}, nil
+}
+
+func (m *MockProvider) Void(_ context.Context, _ string) error { return nil }