From 3fda00bac50a735062f059292f8c0d2a2e606605 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miroslav=20=C5=A0ediv=C3=BD?= <sedivy.miro@gmail.com>
Date: Sun, 3 Jul 2022 23:21:25 +0200
Subject: [PATCH] add video id for webrtc metrics.

---
 internal/webrtc/manager.go |  3 +++
 internal/webrtc/metrics.go | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/internal/webrtc/manager.go b/internal/webrtc/manager.go
index c6dec0c0..e3e454a1 100644
--- a/internal/webrtc/manager.go
+++ b/internal/webrtc/manager.go
@@ -138,6 +138,8 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, videoID strin
 		return nil, types.ErrWebRTCVideoNotFound
 	}
 
+	manager.metrics.SetVideoID(session, videoID)
+
 	connection, err := manager.newPeerConnection([]codec.RTPCodec{
 		audioStream.Codec(),
 		videoStream.Codec(),
@@ -201,6 +203,7 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, videoID strin
 				return types.ErrWebRTCVideoNotFound
 			}
 
+			manager.metrics.SetVideoID(session, videoID)
 			return videoTrack.SetStream(videoStream)
 		},
 		setPaused: func(isPaused bool) {
diff --git a/internal/webrtc/metrics.go b/internal/webrtc/metrics.go
index 42efa7ae..14c99def 100644
--- a/internal/webrtc/metrics.go
+++ b/internal/webrtc/metrics.go
@@ -18,6 +18,9 @@ type metrics struct {
 	iceCandidatesMu    *sync.Mutex
 	iceCandidatesCount prometheus.Counter
 
+	videoIds   map[string]prometheus.Gauge
+	videoIdsMu *sync.Mutex
+
 	iceBytesSent      prometheus.Gauge
 	iceBytesReceived  prometheus.Gauge
 	sctpBytesSent     prometheus.Gauge
@@ -86,6 +89,9 @@ func (m *metricsCtx) getBySession(session types.Session) metrics {
 			},
 		}),
 
+		videoIds:   map[string]prometheus.Gauge{},
+		videoIdsMu: &sync.Mutex{},
+
 		iceBytesSent: promauto.NewGauge(prometheus.GaugeOpts{
 			Name:      "ice_bytes_sent",
 			Namespace: "neko",
@@ -171,6 +177,34 @@ func (m *metricsCtx) SetState(session types.Session, state webrtc.PeerConnection
 	met.connectionStateCount.Add(1)
 }
 
+func (m *metricsCtx) SetVideoID(session types.Session, videoId string) {
+	met := m.getBySession(session)
+
+	met.videoIdsMu.Lock()
+	defer met.videoIdsMu.Unlock()
+
+	if _, found := met.videoIds[videoId]; !found {
+		met.videoIds[videoId] = promauto.NewGauge(prometheus.GaugeOpts{
+			Name:      "video_id",
+			Namespace: "neko",
+			Subsystem: "webrtc",
+			Help:      "Current Video ID of a session.",
+			ConstLabels: map[string]string{
+				"session_id": session.ID(),
+				"video_id":   videoId,
+			},
+		})
+	}
+
+	for id, entry := range met.videoIds {
+		if id == videoId {
+			entry.Set(1)
+		} else {
+			entry.Set(0)
+		}
+	}
+}
+
 func (m *metricsCtx) SetIceTransportStats(session types.Session, data webrtc.TransportStats) {
 	met := m.getBySession(session)