package udp

import (
	"../com"
	"bytes"
)

const (
	SplitChar  = ','
	MaxDataLen = 1024
	PackSize   = 1100
)

type DataPacket struct {
	Seq     uint
	Inner   int
	Payload []byte
}

type EventPacket struct {
	Event string
	Data  *DataPacket
}

func UnpackEventPacket(data []byte) *EventPacket {
	if index := bytes.IndexByte(data, SplitChar); index != -1 {
		event, payload := string(data[:index]), unpackDataPacket(data[index+1:])
		return &EventPacket{Event: event, Data: payload}
	}
	return nil
}

func unpackDataPacket(data []byte) *DataPacket {
	if len(data) == 0 {
		return nil
	}
	seq, inner := com.BytesToUint(data[0:4]), com.BytesToInt(data[4:8])
	return &DataPacket{Seq: seq, Inner: inner, Payload: data[8:]}
}