fix app crashes

remove orphaned streams

pkg/doorbird/backchannel.go

@@ -22,6 +22,7 @@ type AudioMixer struct {
 	streams map[string]chan []byte
 	output  chan []byte
 	running bool
+	closed  bool
 }
 
 func NewAudioMixer() *AudioMixer {
@@ -35,6 +36,12 @@ func (m *AudioMixer) AddStream(id string) chan []byte {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
+	if m.closed {
+		ch := make(chan []byte)
+		close(ch)
+		return ch
+	}
+
 	if !m.running {
 		m.running = true
 		go m.mixLoop()
@@ -138,9 +145,11 @@ func (m *AudioMixer) mixLoop() {
 
 type Client struct {
 	core.Connection
-	conn     net.Conn
+	conn        net.Conn
-	mixer    *AudioMixer
+	mixer       *AudioMixer
-	trackMap map[*core.Sender]string
+	trackMap    map[*core.Sender]string
+	senderStats map[*core.Sender]time.Time
+	mu          sync.RWMutex
 }
 
 func Dial(rawURL string) (*Client, error) {
@@ -200,16 +209,17 @@ func Dial(rawURL string) (*Client, error) {
 	}
 
 	clt = Client{
-		core.Connection{
+		Connection: core.Connection{
 			ID:         core.NewID(),
 			FormatName: "doorbird",
 			Protocol:   "http",
 			URL:        rawURL,
 			Medias:     medias,
 		},
-		conn,
+		conn:        conn,
-		NewAudioMixer(),
+		mixer:       NewAudioMixer(),
-		make(map[*core.Sender]string),
+		trackMap:    make(map[*core.Sender]string),
+		senderStats: make(map[*core.Sender]time.Time),
 	}
 
 	return &clt, nil
@@ -220,20 +230,31 @@ func (c *Client) GetTrack(media *core.Media, codec *core.Codec) (*core.Receiver,
 }
 
 func (c *Client) AddTrack(media *core.Media, codec *core.Codec, track *core.Receiver) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
 	sender := core.NewSender(media, track.Codec)
 	trackID := fmt.Sprintf("%d", core.NewID())
 	streamChan := c.mixer.AddStream(trackID)
 
 	sender.Handler = func(pkt *rtp.Packet) {
-		if c.conn != nil && len(pkt.Payload) > 0 {
+		c.mu.RLock()
+		conn := c.conn
+		c.mu.RUnlock()
+
+		if conn != nil && len(pkt.Payload) > 0 {
 			select {
 			case streamChan <- pkt.Payload:
+				c.mu.Lock()
+				c.senderStats[sender] = time.Now()
+				c.mu.Unlock()
 			default:
 			}
 		}
 	}
 
 	c.trackMap[sender] = trackID
+	c.senderStats[sender] = time.Now()
 
 	if len(c.Senders) == 0 {
 		go func() {
@@ -257,6 +278,15 @@ func (c *Client) Start() error {
 	if c.conn == nil {
 		return nil
 	}
+
+	go func() {
+		ticker := time.NewTicker(5 * time.Second)
+		defer ticker.Stop()
+		for range ticker.C {
+			c.cleanupOrphanedSenders()
+		}
+	}()
+
 	buf := make([]byte, 1)
 	for {
 		_, err := c.conn.Read(buf)
@@ -268,6 +298,9 @@ func (c *Client) Start() error {
 }
 
 func (c *Client) cleanup() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
 	if c.conn != nil {
 		c.conn.Close()
 		c.conn = nil
@@ -275,23 +308,67 @@ func (c *Client) cleanup() {
 
 	if c.mixer != nil {
 		c.mixer.mu.Lock()
-		for id := range c.mixer.streams {
+		c.mixer.closed = true
-			if stream, exists := c.mixer.streams[id]; exists {
+		for id, stream := range c.mixer.streams {
-				close(stream)
+			close(stream)
-			}
+			delete(c.mixer.streams, id)
+		}
+		if c.mixer.running {
+			close(c.mixer.output)
+			c.mixer.running = false
 		}
-		c.mixer.streams = make(map[string]chan []byte)
-		close(c.mixer.output)
-		c.mixer.running = false
 		c.mixer.mu.Unlock()
 	}
 
 	c.trackMap = make(map[*core.Sender]string)
+	c.senderStats = make(map[*core.Sender]time.Time)
+}
+
+func (c *Client) cleanupOrphanedSenders() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	now := time.Now()
+	removedCount := 0
+	validIndex := 0
+
+	for i, sender := range c.Senders {
+		lastActivity, exists := c.senderStats[sender]
+		if sender.State() == "closed" || !exists || now.Sub(lastActivity) >= 5*time.Second {
+			if trackID, exists := c.trackMap[sender]; exists {
+				c.mixer.RemoveStream(trackID)
+				delete(c.trackMap, sender)
+			}
+			delete(c.senderStats, sender)
+			sender.Close()
+			removedCount++
+		} else {
+			c.Senders[validIndex] = c.Senders[i]
+			validIndex++
+		}
+	}
+
+	c.Senders = c.Senders[:validIndex]
+
+	if removedCount > 0 {
+		fmt.Printf("DoorBird: Cleaned up %d orphaned senders, %d remain active\n", removedCount, validIndex)
+	}
 }
 
 func (c *Client) RemoveTrack(sender *core.Sender) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
 	if trackID, exists := c.trackMap[sender]; exists {
 		c.mixer.RemoveStream(trackID)
 		delete(c.trackMap, sender)
 	}
+	delete(c.senderStats, sender)
+
+	for i, s := range c.Senders {
+		if s == sender {
+			c.Senders = append(c.Senders[:i], c.Senders[i+1:]...)
+			break
+		}
+	}
 }