package socks5

import (
	"io"
)

// Reply is the reply packet
type Reply struct {
	Status   ReplyStatus
	ATYP     ATYP
	BindAddr []byte
	BindPort []byte
}

// NewReply returns new reply packet
func NewReply(status ReplyStatus, atyp ATYP, host []byte, port []byte) *Reply {
	return &Reply{
		Status:   status,
		ATYP:     atyp,
		BindAddr: host,
		BindPort: port,
	}
}

// NewReplyFrom reads reply packet from reader
func NewReplyFrom(r io.Reader) (*Reply, error) {
	buf := make([]byte, 4)
	if _, err := io.ReadFull(r, buf); err != nil {
		return nil, err
	}

	if buf[0] != Version {
		return nil, ErrVersion
	}

	addr, err := ReadAddress(r, ATYP(buf[3]))
	if err != nil {
		return nil, err
	}

	port := make([]byte, 2)
	if _, err := io.ReadFull(r, port); err != nil {
		return nil, err
	}

	rep := &Reply{
		Status:   ReplyStatus(buf[1]),
		ATYP:     ATYP(buf[3]),
		BindAddr: addr,
		BindPort: port,
	}

	return rep, nil
}

// WriteTo writes reply packet
func (s *Reply) WriteTo(w io.Writer) (int64, error) {
	buf := []byte{Version, byte(s.Status), Reserved, byte(s.ATYP)}
	buf = append(buf, s.BindAddr...)
	buf = append(buf, s.BindPort...)

	n, err := w.Write(buf)
	if err != nil {
		return int64(n), err
	}

	return int64(n), nil
}