package echo

import (
	"fmt"

	osm "git.loafle.net/overflow/service_matcher-go"
	uuid "github.com/satori/go.uuid"
)

const (
	ECHO_COUNT = 2
)

type EchoMatcher struct {
	osm.Matchers
}

func (m *EchoMatcher) Key(matchCtx *osm.MatchCtx) string {
	return "ECHO"
}

func (m *EchoMatcher) Type(matchCtx *osm.MatchCtx) string {
	return "NETWORK"
}

func (m *EchoMatcher) Vendor(matchCtx *osm.MatchCtx) string {
	return "UNKNOWN"
}

func (m *EchoMatcher) Version(matchCtx *osm.MatchCtx) string {
	return "UNKNOWN"
}

func (m *EchoMatcher) OsType(matchCtx *osm.MatchCtx) string {
	return "UNKNOWN"
}

func (m *EchoMatcher) OsVersion(matchCtx *osm.MatchCtx) string {
	return "UNKNOWN"
}

func (m *EchoMatcher) Name(matchCtx *osm.MatchCtx) string {
	return "ECHO"
}

func (m *EchoMatcher) IsPrePacket() bool {
	return false
}

func (m *EchoMatcher) PacketCount(matchCtx *osm.MatchCtx) int {
	return ECHO_COUNT
}

func (m *EchoMatcher) Packet(matchCtx *osm.MatchCtx, index int) *osm.Packet {
	reqStr := uuid.NewV4().String()
	rbyte := make([]byte, len(reqStr))
	copy(rbyte[:], reqStr)

	matchCtx.SetAttribute(fmt.Sprintf("%d", index), reqStr)

	return osm.NewPacket(rbyte, len(reqStr))
}

func (m *EchoMatcher) HasResponse(matchCtx *osm.MatchCtx, index int) bool {
	return ECHO_COUNT-1 > index
}

func (m *EchoMatcher) IsError(matchCtx *osm.MatchCtx, index int, packet *osm.Packet) bool {
	return false
}

func (m *EchoMatcher) Match(matchCtx *osm.MatchCtx, index int, packet *osm.Packet) error {

	if packet == nil || !packet.Valid() {
		return osm.NoPacketReceivedError()
	}

	sendStr, ok := matchCtx.GetAttribute(fmt.Sprintf("%d", index))
	if !ok {
		return osm.NotMatchedError()
	}

	recvStr := string(packet.Bytes())

	if sendStr != recvStr {
		return osm.NotMatchedError()
	}

	return nil
}

func NewMatcher() osm.Matcher {
	m := &EchoMatcher{}

	return m
}