Add ArtRDM TOD discovery support

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

protocol.go

@@ -13,15 +13,16 @@ const (
 	Port            = 6454
 	ProtocolVersion = 14
 
-	OpPoll      uint16 = 0x2000
-	OpPollReply uint16 = 0x2100
-	OpDmx       uint16 = 0x5000
-	OpSync      uint16 = 0x5200
-	OpAddress   uint16 = 0x6000
-	OpInput     uint16 = 0x7000
-	OpTodData   uint16 = 0x8100
+	OpPoll       uint16 = 0x2000
+	OpPollReply  uint16 = 0x2100
+	OpDmx        uint16 = 0x5000
+	OpSync       uint16 = 0x5200
+	OpAddress    uint16 = 0x6000
+	OpInput      uint16 = 0x7000
+	OpTodRequest uint16 = 0x8000
+	OpTodData    uint16 = 0x8100
 	OpTodControl uint16 = 0x8200
-	OpRdm       uint16 = 0x8300
+	OpRdm        uint16 = 0x8300
 
 	PortTypeOutput uint8 = 0x80
 	PortTypeInput  uint8 = 0x40
@@ -29,6 +30,8 @@ const (
 	GoodOutputDataTransmitted uint8 = 0x80
 	GoodInputDataReceived     uint8 = 0x80
 
+	TodCommandFull uint8 = 0x00
+
 	StyleNode       uint8 = 0x00
 	StyleController uint8 = 0x01
 	StyleMedia      uint8 = 0x02
@@ -148,6 +151,33 @@ func (p *PollReplyPacket) OutputUniverses() []Universe {
 	return result
 }
 
+type RDMUID [6]byte
+
+func (u RDMUID) Manufacturer() uint16 {
+	return uint16(u[0])<<8 | uint16(u[1])
+}
+
+func (u RDMUID) Device() uint32 {
+	return uint32(u[2])<<24 | uint32(u[3])<<16 | uint32(u[4])<<8 | uint32(u[5])
+}
+
+func (u RDMUID) String() string {
+	return fmt.Sprintf("%04x:%08x", u.Manufacturer(), u.Device())
+}
+
+type TodDataPacket struct {
+	RdmVer      uint8
+	Port        uint8
+	BindIndex   uint8
+	Net         uint8
+	Command     uint8
+	Universe    Universe
+	UidTotal    uint16
+	BlockCount  uint8
+	UidCount    uint8
+	UIDs        []RDMUID
+}
+
 func ParsePacket(data []byte) (uint16, interface{}, error) {
 	if len(data) < 10 {
 		return 0, nil, ErrPacketTooShort
@@ -169,6 +199,9 @@ func ParsePacket(data []byte) (uint16, interface{}, error) {
 	case OpPollReply:
 		pkt, err := parsePollReplyPacket(data)
 		return opCode, pkt, err
+	case OpTodData:
+		pkt, err := parseTodDataPacket(data)
+		return opCode, pkt, err
 	default:
 		return opCode, nil, nil
 	}
@@ -279,6 +312,53 @@ func BuildPollPacket() []byte {
 	return buf
 }
 
+func parseTodDataPacket(data []byte) (*TodDataPacket, error) {
+	if len(data) < 28 {
+		return nil, ErrPacketTooShort
+	}
+
+	pkt := &TodDataPacket{
+		RdmVer:     data[10],
+		Port:       data[11],
+		BindIndex:  data[20],
+		Net:        data[21],
+		Command:    data[22],
+		Universe:   NewUniverse(data[21], data[23]>>4, data[23]&0x0F),
+		UidTotal:   binary.BigEndian.Uint16(data[24:26]),
+		BlockCount: data[26],
+		UidCount:   data[27],
+	}
+
+	uidCount := int(pkt.UidCount)
+	if uidCount > 200 {
+		uidCount = 200
+	}
+
+	expectedLen := 28 + uidCount*6
+	if len(data) < expectedLen {
+		uidCount = (len(data) - 28) / 6
+	}
+
+	pkt.UIDs = make([]RDMUID, uidCount)
+	for i := 0; i < uidCount; i++ {
+		copy(pkt.UIDs[i][:], data[28+i*6:28+i*6+6])
+	}
+
+	return pkt, nil
+}
+
+func BuildTodRequestPacket(net, subnet, universe uint8) []byte {
+	buf := make([]byte, 25)
+	copy(buf[0:8], ID[:])
+	binary.LittleEndian.PutUint16(buf[8:10], OpTodRequest)
+	binary.BigEndian.PutUint16(buf[10:12], ProtocolVersion)
+	buf[20] = net
+	buf[21] = TodCommandFull
+	buf[22] = 1
+	buf[23] = subnet<<4 | (universe & 0x0F)
+	return buf
+}
+
 func BuildPollReplyPacket(ip [4]byte, mac [6]byte, shortName, longName string, universes []Universe, isInput bool) []byte {
 	buf := make([]byte, 240)
 	copy(buf[0:8], ID[:])