package artnet

import (
	"net"
	"sync"
)

// Sender sends ArtNet packets
type Sender struct {
	conn      *net.UDPConn
	sequences map[Universe]uint8
	seqMu     sync.Mutex
}

// NewSender creates a new ArtNet sender
func NewSender() (*Sender, error) {
	// Create a UDP socket for sending
	conn, err := net.ListenUDP("udp4", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
	if err != nil {
		return nil, err
	}

	// Enable broadcast
	if err := conn.SetWriteBuffer(65536); err != nil {
		conn.Close()
		return nil, err
	}

	return &Sender{
		conn:      conn,
		sequences: make(map[Universe]uint8),
	}, nil
}

// SendDMX sends a DMX packet to a specific address
func (s *Sender) SendDMX(addr *net.UDPAddr, universe Universe, data []byte) error {
	s.seqMu.Lock()
	seq := s.sequences[universe]
	seq++
	if seq == 0 {
		seq = 1 // Skip 0
	}
	s.sequences[universe] = seq
	s.seqMu.Unlock()

	pkt := BuildDMXPacket(universe, seq, data)
	_, err := s.conn.WriteToUDP(pkt, addr)
	return err
}

// SendPoll sends an ArtPoll packet to the specified address
func (s *Sender) SendPoll(addr *net.UDPAddr) error {
	pkt := BuildPollPacket()
	_, err := s.conn.WriteToUDP(pkt, addr)
	return err
}

// SendPollReply sends an ArtPollReply to a specific address
func (s *Sender) SendPollReply(addr *net.UDPAddr, localIP [4]byte, shortName, longName string, universes []Universe) error {
	pkt := BuildPollReplyPacket(localIP, shortName, longName, universes)
	_, err := s.conn.WriteToUDP(pkt, addr)
	return err
}

// Close closes the sender
func (s *Sender) Close() error {
	return s.conn.Close()
}