Clear stale unanswered calls before new invite

server/calls.go

@@ -95,6 +95,8 @@ type videoCall struct {
 	callID string
 	// Product-level call type: audio or video.
 	callType string
+	// Time when the invite was accepted by the server.
+	startedAt time.Time
 	// Time when the call was accepted.
 	acceptedAt time.Time
 }
@@ -168,6 +170,13 @@ func (call *videoCall) matchesPayload(payload any) bool {
 	return payloadCallID == "" || payloadCallID == call.callID
 }
 
+func (call *videoCall) isStaleUnanswered(now time.Time, timeoutSeconds int) bool {
+	if call == nil || len(call.parties) != 1 || call.startedAt.IsZero() || timeoutSeconds <= 0 {
+		return false
+	}
+	return now.Sub(call.startedAt) > time.Duration(timeoutSeconds)*time.Second
+}
+
 func (t *Topic) auditCallCreate(call *videoCall, caller types.Uid) {
 	if store.Calls == nil || call == nil || call.callID == "" || caller.IsZero() {
 		return
@@ -350,6 +359,7 @@ func (t *Topic) handleCallInvite(msg *ClientComMessage, asUid types.Uid) {
 		contentMime: msg.Pub.Head["mime"],
 		callID:      callContentString(msg.Pub.Content, "callId"),
 		callType:    callContentString(msg.Pub.Content, "callType"),
+		startedAt:   types.TimeNow(),
 	}
 	t.currentCall.parties[msg.sess.sid] = callPartyData{
 		uid:          asUid,