package forward

import (
	"errors"
	"io"
	"net"

	"git.lovezsh.com/lovezsh/nip/internal/pkg/encoding"
	"git.lovezsh.com/lovezsh/nip/internal/proto"
)

type Forwarder interface {
	Forward(net.Conn, string) (err error)
}

type forwarder struct {
	server string
	token  string
}

func New(server string, token string) Forwarder {
	return &forwarder{server, token}
}

func (f *forwarder) Forward(src net.Conn, target string) (err error) {
	dst, err := net.Dial("tcp", f.server)
	if err != nil {
		return err
	}
	defer dst.Close()

	req := proto.Request{
		Target: target,
		Token:  f.token,
	}
	if err = encoding.NewEncoder(dst).Encode(&req); err != nil {
		return
	}

	var resp proto.Response
	if err = encoding.NewDecoder(dst).Decode(&resp); err != nil {
		return
	}

	if resp.Code != 0 {
		return errors.New(resp.Message)
	}

	ch := make(chan error)
	go func() {
		_, err := io.Copy(dst, src)
		ch <- err
	}()
	go func() {
		_, err := io.Copy(src, dst)
		ch <- err
	}()
	return <-ch
}