feat: implement real ping RTT calculation instead of hardcoded 50ms

internal/client/client.go

@@ -37,6 +37,12 @@ type Client struct {
 	PongPacketID       uint16 // Type 0x05
 	AckPacketID        uint16 // Type 0x06
 
+	// Ping RTT tracking
+	PingSentTimes   map[uint16]time.Time // Map PingPacketID -> Time sent
+	PingRTT         float64              // Rolling average RTT in ms
+	PingDeviation   float64              // Rolling deviation in ms
+	PingSampleCount int                  // Number of samples for rolling avg
+
 	// State
 	Connected  bool
 	ServerName string
@@ -70,6 +76,9 @@ func NewClient(nickname string) *Client {
 		VoiceDecoders:      make(map[uint16]*opus.Decoder),
 		CommandQueue:       make(map[uint16]*protocol.Packet),
 		ExpectedCommandPID: 0,
+		PingSentTimes:      make(map[uint16]time.Time),
+		PingRTT:            0,
+		PingDeviation:      0,
 		done:               make(chan struct{}),
 	}
 }
@@ -187,6 +196,9 @@ func (c *Client) sendPing() error {
 	pkt.Data = encData
 	copy(pkt.Header.MAC[:], mac)
 
+	// Record send time for RTT calculation
+	c.PingSentTimes[pkt.Header.PacketID] = time.Now()
+
 	log.Printf("Sending proper Encrypted Ping (PID=%d)", pkt.Header.PacketID)
 	return c.Conn.SendPacket(pkt)
 }