package models

import (
	"bytes"
	"encoding/binary"
)

// Art-Net constants
const (
	opCode     = 0x5000 // OpDmx (low byte first)
	protocolID = "Art-Net\x00"
)

type Package []byte

func NewArtNetPackage(data *DMX) Package {
	// Build ArtDMX packet
	packet := &bytes.Buffer{}
	packet.WriteString(protocolID)                             // Art-Net ID
	binary.Write(packet, binary.LittleEndian, uint16(opCode))  // OpCode (OpDmx)
	packet.WriteByte(0x00)                                     // Protocol Version High
	packet.WriteByte(14)                                       // Protocol Version Low (14 for Art-Net 4)
	packet.WriteByte(0x00)                                     // Sequence
	packet.WriteByte(0x00)                                     // Physical
	binary.Write(packet, binary.BigEndian, uint16(0))          // Universe (net:subuni, usually 0)
	binary.Write(packet, binary.BigEndian, uint16(len(*data))) // Length
	packet.Write(*data)
	return packet.Bytes()
}