package udp

import (
	"log/slog"
	"net"
)

type UdpClient interface {
	SendMsg(msg UdpMessageEncoder)
	Send(b []byte)
}

type client struct {
	laddr *net.UDPAddr
	raddr *net.UDPAddr
	conn  *net.UDPConn
}

// 新建UDP客户端
// remoteAddr - 远端地址, 如 127.0.0.1:7777
func NewClient(remoteAddr string) UdpClient {
	addr, err := net.ResolveUDPAddr("udp", remoteAddr)
	if err != nil {
		panic(err)
	}
	var laddr *net.UDPAddr = nil
	conn, err := net.DialUDP("udp", laddr, addr)
	if err != nil {
		panic(err)
	}
	c := &client{
		laddr: laddr,
		raddr: addr,
		conn:  conn,
	}
	return c
}

// 新建UDP客户端
// remoteAddr - 远端地址, 如 127.0.0.1:7777
// localAddr - 本地地址, 如 :9999
func NewClientWithLocalAddr(remoteAddr string, localAddr string) UdpClient {
	addr, err := net.ResolveUDPAddr("udp", remoteAddr)
	if err != nil {
		panic(err)
	}
	laddr, err := net.ResolveUDPAddr("udp", localAddr)
	if err != nil {
		slog.Info("UDP客户端使用随机端口")
		laddr = nil
	}
	conn, err := net.DialUDP("udp", laddr, addr)
	if err != nil {
		panic(err)
	}
	c := &client{
		laddr: laddr,
		raddr: addr,
		conn:  conn,
	}
	return c
}

func (c *client) SendMsg(msg UdpMessageEncoder) {
	b := msg.Encode()
	_, err := c.conn.Write(b)
	if err != nil {
		slog.Error("udp client send error", "error", err)
	}
	// slog.Debug("udp client send", "size", n)
}

func (c *client) Send(b []byte) {
	_, err := c.conn.Write(b)
	if err != nil {
		slog.Error("udp client send error", "error", err)
	}
	// slog.Debug("udp client send", "size", n)
}