package peer

import "unsafe"

type Nonce struct {
	Counter    uint64
	SourceIP   byte
	ViaIP      byte
	DestIP     byte
	StreamID   byte // The stream, see STREAM_* constants
	PacketType byte // The packet type. See PACKET_* constants.
}

func (nonce *Nonce) Parse(nb []byte) {
	nonce.Counter = *(*uint64)(unsafe.Pointer(&nb[0]))
	nonce.SourceIP = nb[8]
	nonce.ViaIP = nb[9]
	nonce.DestIP = nb[10]
	nonce.StreamID = nb[11]
	nonce.PacketType = nb[12]
}

func (nonce Nonce) Marshal(buf []byte) {
	*(*uint64)(unsafe.Pointer(&buf[0])) = nonce.Counter
	buf[8] = nonce.SourceIP
	buf[9] = nonce.ViaIP
	buf[10] = nonce.DestIP
	buf[11] = nonce.StreamID
	buf[12] = nonce.PacketType
}

func CounterTimestamp(counter uint64) int64 {
	return int64(counter >> 30)
}