switch to unmarshal marshal

poll.go

@@ -1,11 +1,16 @@
 package artnet
 
 import (
+	"encoding/binary"
 	"errors"
+	"slices"
 )
 
 type ArtPoll struct {
-	Header          *ArtNetHeader
+	ID              []uint8
+	OpCode          uint16
+	ProtVerHi       uint8
+	ProtVerLo       uint8
 	Flags           uint8
 	DiagPriority    uint8
 	AddressTopHi    uint8
@@ -18,23 +23,54 @@ type ArtPoll struct {
 	OemLo           uint8
 }
 
-func NewArtPoll(header *ArtNetHeader, data []byte) (*ArtPoll, error) {
-	artPoll := ArtPoll{
-		Header: header,
-	}
+func NewArtPoll(data []byte) (*ArtPoll, error) {
+	artPoll := ArtPoll{}
 
-	if len(data) < 14 {
-		return nil, errors.New("ArtPoll packet must be at least 14 bytes long")
-	}
-	offset := 12
-	artPoll.Flags = data[offset]
-	artPoll.DiagPriority = data[offset+1]
+	err := artPoll.UnmarshalBinary(data)
 
-	//TODO(jwetzell): unpack extended poll fields
+	if err != nil {
+		return nil, err
+	}
 
 	return &artPoll, nil
 }
 
 func (ap *ArtPoll) GetOpCode() uint16 {
-	return ap.Header.OpCode
+	return ap.OpCode
+}
+
+func (ap *ArtPoll) GetProtVer() uint16 {
+	return uint16(ap.ProtVerHi)<<8 + uint16(ap.ProtVerLo)
+}
+
+func (ap *ArtPoll) GetID() []uint8 {
+	return ap.ID
+}
+
+func (ap *ArtPoll) UnmarshalBinary(data []byte) error {
+
+	if len(data) < 14 {
+		return errors.New("ArtPoll packet must be at least 14 bytes long")
+	}
+
+	if !slices.Equal(ArtNetID, data[0:8]) {
+		return errors.New("ID does not match Art-Net ID")
+	}
+
+	ap.OpCode = binary.LittleEndian.Uint16(data[8:10])
+	ap.ProtVerHi = data[10]
+	ap.ProtVerLo = data[11]
+
+	offset := 12
+	ap.Flags = data[offset]
+	ap.DiagPriority = data[offset+1]
+	//TODO(jwetzell): unpack extended poll fields
+	return nil
+}
+
+func (ap *ArtPoll) MarshalBinary() ([]byte, error) {
+	data := []byte(ArtNetID)
+	data = append(data, byte(ap.OpCode), byte(ap.OpCode>>8), ap.ProtVerHi, ap.ProtVerLo, ap.Flags, ap.DiagPriority)
+	//TODO(jwetzell): pack extended poll fields
+	return data, nil
 }