queue: include send time in messages

cmd/kaiyan-ingest/main.go

@@ -125,10 +125,20 @@ func webhook(q *kgo.Client, secret []byte, errs chan<- error) http.HandlerFunc {
 				slog.String("broadcaster", ev.Event.Broadcaster),
 				slog.String("id", ev.Event.ID),
 			)
+			// Use the external clock for timestamps.
+			tm, err := time.Parse(time.RFC3339Nano, r.Header.Get("Twitch-Eventsub-Message-Timestamp"))
+			if err != nil {
+				log.LogAttrs(ctx, slog.LevelWarn, "bad timestamp",
+					slog.String("timestamp", r.Header.Get("Twitch-Eventsub-Message-Timestamp")),
+					slog.Any("err", err),
+				)
+				tm = time.Now()
+			}
 			msg := queue.Message{
 				ID:        ev.Event.ID,
 				Channel:   ev.Event.Broadcaster,
 				Sender:    queue.Sender(secret, ev.Event.Broadcaster, ev.Event.Chatter),
+				Timestamp: tm.UnixNano(),
 				Text:      ev.Event.Message.Text,
 			}
 			// TODO(branden): the context in the http request cancels once this

queue/message.go

@@ -18,6 +18,9 @@ type Message struct {
 	Channel string `json:"ch"`
 	// Sender is an obfuscated identifier for the sending user.
 	Sender sender `json:"u"`
+	// Timestamp is the time at which the message was sent in nanoseconds since
+	// the Unix epoch.
+	Timestamp int64 `json:"ts"`
 	// Text is the message content.
 	Text string `json:"t"`
 }

queue/message_test.go

@@ -24,6 +24,7 @@ func TestSend(t *testing.T) {
 		ID:        "bocchi",
 		Channel:   "kessoku",
 		Sender:    queue.Sender(make([]byte, 16), "kessoku", "ryō"),
+		Timestamp: 1,
 		Text:      "bocchi the rock!",
 	}
 	var q spyProducer