package socks5

import (
	"io"
)

// Request is the request packet
type Request struct {
	Command Command
	ATYP    ATYP
	DstAddr []byte
	DstPort []byte
}

// NewRequest returns new request packet
func NewRequest(command Command, atyp ATYP, host []byte, port []byte) *Request {
	return &Request{
		Command: command,
		ATYP:    atyp,
		DstAddr: host,
		DstPort: port,
	}
}

// NewRequestFrom reads request packet from client
func NewRequestFrom(r io.Reader) (*Request, 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
	}

	req := &Request{
		Command: Command(buf[1]),
		ATYP:    ATYP(buf[3]),
		DstAddr: addr,
		DstPort: port,
	}

	return req, nil
}

// WriteTo writes request packet
func (s *Request) WriteTo(w io.Writer) (int64, error) {
	buf := []byte{Version, byte(s.Command), Reserved, byte(s.ATYP)}
	buf = append(buf, s.DstAddr...)
	buf = append(buf, s.DstPort...)

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

	return int64(n), nil
}