From 7579a341d50f48a4f077b9576c11e6e608b67dc0 Mon Sep 17 00:00:00 2001
From: Laurent Le Houerou <laurent@lehouerou.net>
Date: Tue, 23 Jun 2020 09:59:40 +0400
Subject: [PATCH] gestion du lastid

---
 event_stream.go | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/event_stream.go b/event_stream.go
index 1ba84e3..b4442ac 100644
--- a/event_stream.go
+++ b/event_stream.go
@@ -23,6 +23,9 @@ type eventStream struct {
 	isConnected      bool
 	isConnectedMutex sync.RWMutex
 
+	lastId      string
+	lastIdMutex sync.RWMutex
+
 	transactionSubscribers      map[string]chan *EventStreamResponse
 	transactionSubscribersMutex sync.RWMutex
 
@@ -30,7 +33,7 @@ type eventStream struct {
 	resourceSubscribersMutex sync.RWMutex
 }
 
-func newEventStream(url string, client *http.Client, authHeader string) *eventStream {
+func newEventStream(url string, client *http.Client, authHeader string, lastId string) *eventStream {
 	e := &eventStream{
 		Events:                      make(chan *sse.Event),
 		transactionSubscribers:      make(map[string]chan *EventStreamResponse),
@@ -41,11 +44,16 @@ func newEventStream(url string, client *http.Client, authHeader string) *eventSt
 		once:                        new(sync.Once),
 		isConnected:                 false,
 		isConnectedMutex:            sync.RWMutex{},
+		lastId:                      "",
+		lastIdMutex:                 sync.RWMutex{},
 	}
 
 	SSEClient := sse.NewClient(url)
 	SSEClient.Connection = client
 	SSEClient.Headers["Authorization"] = authHeader
+	if lastId != "" {
+		SSEClient.Headers["Last-Event-ID"] = lastId
+	}
 	SSEClient.OnDisconnect(func(c *sse.Client) {
 		e.disconnect()
 	})
@@ -87,6 +95,10 @@ func (e *eventStream) listen(ctx context.Context) error {
 					continue
 				}
 
+				if event.ID != nil {
+					e.setLastId(string(event.ID))
+				}
+
 				var notifyResponse EventStreamResponse
 				err := json.NewDecoder(bytes.NewBuffer(event.Data)).Decode(&notifyResponse)
 				if err != nil {
@@ -198,3 +210,15 @@ func (e *eventStream) clearTransactionSubscriptions() {
 	}
 	e.transactionSubscribers = make(map[string]chan *EventStreamResponse)
 }
+
+func (e *eventStream) GetLastId() string {
+	e.lastIdMutex.RLock()
+	defer e.lastIdMutex.RUnlock()
+	return e.lastId
+}
+
+func (e *eventStream) setLastId(value string) {
+	e.lastIdMutex.Lock()
+	defer e.lastIdMutex.Unlock()
+	e.lastId = value
+}