add video to livekit calls

src/app/voice.ts

@@ -29,6 +29,7 @@ export type VoiceSession = {
   h: string
   room: LiveKitRoom
   muted: boolean
+  cameraOn: boolean
 }
 
 export type Pubkey = string
@@ -49,6 +50,11 @@ export const currentVoiceRoom = writable<Room | undefined>(undefined)
 
 export const participantPubkeyMap = writable<Map<string, Pubkey>>(new Map())
 
+/** Bumps when remote video is subscribed/unsubscribed so layout/video UI can react. */
+export const videoCallLayoutRevision = writable(0)
+
+const bumpVideoCallLayoutRevision = () => videoCallLayoutRevision.update(n => n + 1)
+
 const addParticipant = (identity: string) => {
   participantPubkeyMap.update(m => {
     const next = new Map(m)
@@ -164,6 +170,7 @@ const setUpMicrophone = async (
 }
 
 const onRoomDisconnected = (reason?: DisconnectReason) => {
+  videoCallLayoutRevision.set(0)
   currentVoiceSession.set(undefined)
   if (reason !== undefined && reason !== DisconnectReason.CLIENT_INITIATED) {
     voiceState.set(VoiceState.Disconnected)
@@ -183,11 +190,16 @@ const onTrackSubscribed = (track: Track) => {
     element.style.display = "none"
     document.body.appendChild(element)
     element.play().catch(() => {})
+  } else if (track.kind === Track.Kind.Video) {
+    bumpVideoCallLayoutRevision()
   }
 }
 
 const onTrackUnsubscribed = (track: Track) => {
   track.detach().forEach(el => el.remove())
+  if (track.kind === Track.Kind.Video) {
+    bumpVideoCallLayoutRevision()
+  }
 }
 
 const onActiveSpeakersChanged = (participants: {identity: string}[]) => {
@@ -268,7 +280,7 @@ export const joinVoiceRoom = async (
 
     const muted = await setUpMicrophone(startMuted, preferredMicId, liveKitRoom.localParticipant)
 
-    currentVoiceSession.set({url, h, room: liveKitRoom, muted})
+    currentVoiceSession.set({url, h, room: liveKitRoom, muted, cameraOn: false})
     voiceState.set(VoiceState.Connected)
     playJoinSound()
   } catch (e) {
@@ -287,7 +299,16 @@ export const leaveVoiceRoom = async () => {
   const audio = new Audio("/leave-voice-room.mp3")
   audio.play().catch(() => {})
 
+  if (session.cameraOn) {
+    try {
+      await session.room.localParticipant.setCameraEnabled(false)
+    } catch {
+      /* pass */
+    }
+  }
+
   voiceState.set(VoiceState.Disconnected)
+  videoCallLayoutRevision.set(0)
   currentVoiceSession.set(undefined)
   session.room.disconnect()
   speakingParticipants.set([])
@@ -319,3 +340,66 @@ export const toggleMute = async () => {
     pushToast({theme: "error", message: "Could not access microphone"})
   }
 }
+
+const roomHasSubscribedRemoteCamera = (room: LiveKitRoom): boolean => {
+  for (const p of room.remoteParticipants.values()) {
+    const pub = p.getTrackPublication(Track.Source.Camera)
+    if (pub?.isSubscribed && pub.track) return true
+  }
+  return false
+}
+
+/** True when the connected session has local camera on or any subscribed remote camera track. */
+export const videoCallContentActive = derived(
+  [currentVoiceSession, voiceState, videoCallLayoutRevision],
+  ([$session, $state, _rev]) => {
+    if ($state !== VoiceState.Connected || !$session) return false
+    if ($session.cameraOn) return true
+    return roomHasSubscribedRemoteCamera($session.room)
+  },
+)
+
+/** Live camera tracks (local + remote) for layout automation. */
+const countLiveCameraFeeds = (session: VoiceSession): number => {
+  const room = session.room
+  let n = 0
+  const lp = room.localParticipant
+  if (session.cameraOn) {
+    const pub = lp.getTrackPublication(Track.Source.Camera)
+    if (pub?.track) n += 1
+  }
+  for (const rp of room.remoteParticipants.values()) {
+    const pub = rp.getTrackPublication(Track.Source.Camera)
+    if (pub?.isSubscribed && pub.track) n += 1
+  }
+  return n
+}
+
+export const videoTileCount = derived(
+  [currentVoiceSession, voiceState, videoCallLayoutRevision],
+  ([$session, $state, _rev]) => {
+    if ($state !== VoiceState.Connected || !$session) return 0
+    return countLiveCameraFeeds($session)
+  },
+)
+
+export const toggleCamera = async () => {
+  const session = get(currentVoiceSession)
+  if (!session) return
+
+  const cameraOn = !session.cameraOn
+  if (!cameraOn) {
+    session.room.localParticipant.setCameraEnabled(false)
+    currentVoiceSession.set({...session, cameraOn})
+    bumpVideoCallLayoutRevision()
+    return
+  }
+
+  try {
+    await session.room.localParticipant.setCameraEnabled(true)
+    currentVoiceSession.set({...session, cameraOn})
+    bumpVideoCallLayoutRevision()
+  } catch (e) {
+    pushToast({theme: "error", message: "Could not access camera"})
+  }
+}