package main

import (
	"flag"
	"fmt"
	"log"
	"net"
	"os"

	"github.com/goburrow/netforward"
	"tailscale.com/tsnet"
)

var (
	host_proto = flag.Arg(0)
	hostname   = flag.Arg(1)
	host_port  = flag.Arg(2)
	dst_proto  = flag.Arg(3)
	dst_addr   = flag.Arg(4)
)

type Dialer struct{}

func (dialer Dialer) Dial() (net.Conn, error) {
	return net.Dial(dst_proto, dst_addr)
}

func main() {
	flag.Parse()
	if !(host_proto != "" && hostname != "" && host_port != "" && dst_proto != "" && dst_addr != "") {
		fmt.Println("Usage: tsnet-proxy PROTO HOSTNAME PORT DST-PROTO DST")
		fmt.Println("Where PROTO is one of tcp, udp, unix")
		os.Exit(1)
	}

	s := &tsnet.Server{
		Hostname: hostname,
	}
	defer s.Close()

	ln, err := s.Listen(host_proto, fmt.Sprint(":", host_port))
	if err != nil {
		log.Fatal(err)
	}
	defer ln.Close()
	err = netforward.Forward(Dialer{}, ln)
	if err != nil {
		log.Fatal(err)
	}
}