package proxy

import (
	"net"
	"time"

	"github.com/xjasonlyu/clash/component/resolver"
)

const (
	tcpConnectTimeout  = 5 * time.Second
	tcpKeepAlivePeriod = 30 * time.Second
)

func tcpKeepAlive(c net.Conn) {
	if tcp, ok := c.(*net.TCPConn); ok {
		tcp.SetKeepAlive(true)
		tcp.SetKeepAlivePeriod(tcpKeepAlivePeriod)
	}
}

func resolveUDPAddr(network, address string) (*net.UDPAddr, error) {
	host, port, err := net.SplitHostPort(address)
	if err != nil {
		return nil, err
	}

	ip, err := resolver.ResolveIP(host)
	if err != nil {
		return nil, err
	}
	return net.ResolveUDPAddr(network, net.JoinHostPort(ip.String(), port))
}