package plain

import (
	"bytes"
	"git.noahlan.cn/noahlan/nnet/packet"
)

type Packer struct {
	buf  *bytes.Buffer
	size int  // 最近一次 length
	typ  byte // 最近一次 packet type
	flag byte // 最近一次 flag
}

func NewPacker() *Packer {
	p := &Packer{
		buf: bytes.NewBuffer(nil),
	}
	p.resetFlags()
	return p
}

func (d *Packer) resetFlags() {
}

func (d *Packer) Pack(_ any, data []byte) ([]byte, error) {
	buf := make([]byte, len(data))
	copy(buf, data)
	return buf, nil
}

func (d *Packer) Unpack(data []byte) ([]packet.IPacket, error) {
	d.buf.Write(data) // copy
	var packets []packet.IPacket

	p := newPacket()
	p.Data = d.buf.Next(d.buf.Len())
	packets = append(packets, p)

	return packets, nil
}