support for EOSE and OK messages on relay/subscription.

relay.go

@@ -40,6 +40,7 @@ type Relay struct {
 	subscriptions s.MapOf[string, *Subscription]
 
 	Notices     chan string
+	statusChans s.MapOf[string, chan Status]
 }
 
 func NewRelay(url string) *Relay {
@@ -124,6 +125,33 @@ func (r *Relay) Connect() error {
 					subscription.Events <- event
 				}
 			}
+		case "EOSE":
+			if len(jsonMessage) < 2 {
+				continue
+			}
+			var channel string
+			json.Unmarshal(jsonMessage[1], &channel)
+			if subscription, ok := r.subscriptions.Load(channel); ok {
+				subscription.EndOfStoredEvents <- struct{}{}
+			}
+		case "OK":
+			if len(jsonMessage) < 3 {
+				continue
+			}
+			var (
+				eventId string
+				ok      bool
+			)
+			json.Unmarshal(jsonMessage[1], &eventId)
+			json.Unmarshal(jsonMessage[2], &ok)
+
+			if statusChan, ok := r.statusChans.Load(eventId); ok {
+				if ok {
+					statusChan <- PublishStatusSucceeded
+				} else {
+					statusChan <- PublishStatusFailed
+				}
+			}
 		}
 	}
 }
@@ -132,6 +160,10 @@ func (r Relay) Publish(event Event) chan Status {
 	statusChan := make(chan Status)
 
 	go func() {
+		// we keep track of this so the OK message can be used to close it
+		r.statusChans.Store(event.ID, statusChan)
+		defer r.statusChans.Delete(event.ID)
+
 		err := r.Connection.WriteJSON([]interface{}{"EVENT", event})
 		if err != nil {
 			statusChan <- PublishStatusFailed

subscription.go

@@ -6,6 +6,7 @@ type Subscription struct {
 
 	filters           Filters
 	Events            chan Event
+	EndOfStoredEvents chan struct{}
 
 	stopped bool
 }