events: InvoiceCreated InvoiceSettled

events/events.go

@@ -1,3 +1,15 @@
 package events
 
-type Event struct{}
+const (
+	InvoiceCreated = "invoice.created"
+	InvoiceSettled = "invoice.settled"
+)
+
+type Event struct {
+	Type string
+	ID   string
+}
+
+func New(kind string) *Event {
+	return &Event{Type: kind}
+}

pubsub/pubsub.go

@@ -42,6 +42,11 @@ func (p *pubSub) invoices(ctx context.Context, sub chan *events.Event) {
 			default:
 				invoice := <-invoices
 				p.logger.Debug("receive invoice", logging.Object("invoice", invoice))
+				if invoice.Settled {
+					sub <- events.New(events.InvoiceSettled)
+				} else {
+					sub <- events.New(events.InvoiceCreated)
+				}
 			}
 		}
 	}()