package service

import (
	"fmt"
	"net"
	"time"

	omd "git.loafle.net/overflow/model/discovery"
	osm "git.loafle.net/overflow/service_matcher-go"
	ouej "git.loafle.net/overflow/util-go/encoding/json"
	ounp "git.loafle.net/overflow/util-go/net/ping"
	"git.loafle.net/overflow_scanner/probe/internal/matcher"
)

func matcherPingFunc(service *omd.Service, pingOption ounp.Option) (ttl int, err error) {
	var portNumber int
	portNumber, err = ouej.NumberToInt(service.Port.PortNumber)
	if nil != err {
		return
	}

	matchCtx := osm.NewMatchCtx(service.Port.Host.Address, portNumber)
	_matcher := matcher.GetMatcherByKey(service.Key)

	if _matcher.IsPrePacket() {
		return processPrepacket(service, pingOption, matchCtx, _matcher)
	}
	return processPostpacket(service, pingOption, matchCtx, _matcher)
}

func processPrepacket(service *omd.Service, pingOption ounp.Option, matchCtx *osm.MatchCtx, _matcher osm.Matcher) (ttl int, err error) {

	var conn net.Conn
	var bufLen int
	buf := make([]byte, 1024)

	conn, err = getConnection(service, pingOption)
	if nil != err {
		return
	}
	defer conn.Close()

	err = conn.SetReadDeadline(time.Now().Add(time.Duration(pingOption.GetDeadline()) * time.Second))
	if nil != err {
		return
	}
	bufLen, err = conn.Read(buf)
	if nil != err {
		return
	}

	err = _matcher.Match(matchCtx, 0, osm.NewPacket(buf, bufLen))
	if nil != err {
		return
	}

	packetCount := _matcher.PacketCount(matchCtx)

	if 0 == packetCount {
		return
	}

	for indexM := 0; indexM < packetCount; indexM++ {
		_packet := _matcher.Packet(matchCtx, indexM)

		err = conn.SetWriteDeadline(time.Now().Add(time.Duration(pingOption.GetDeadline()) * time.Second))
		if nil != err {
			return
		}
		_, err = conn.Write(_packet.Buffer)
		if nil != err {
			return
		}

		err = conn.SetReadDeadline(time.Now().Add(time.Duration(pingOption.GetDeadline()) * time.Second))
		if nil != err {
			return
		}
		bufLen, err = conn.Read(buf)
		if nil != err {
			return
		}

		err = _matcher.Match(matchCtx, indexM+1, osm.NewPacket(buf, bufLen))
		if nil != err {
			err = fmt.Errorf("Protocol not match")
			return
		}
	}

	return
}

func processPostpacket(service *omd.Service, pingOption ounp.Option, matchCtx *osm.MatchCtx, _matcher osm.Matcher) (ttl int, err error) {
	var conn net.Conn
	var bufLen int
	buf := make([]byte, 1024)

	packetCount := _matcher.PacketCount(matchCtx)

	if 0 == packetCount {
		err = fmt.Errorf("Protocol not match")
		return
	}

	conn, err = getConnection(service, pingOption)
	if nil != err {
		return
	}
	defer conn.Close()

	for indexM := 0; indexM < packetCount; indexM++ {
		_packet := _matcher.Packet(matchCtx, indexM)

		err = conn.SetWriteDeadline(time.Now().Add(time.Duration(pingOption.GetDeadline()) * time.Second))
		if nil != err {
			return
		}
		_, err = conn.Write(_packet.Buffer)
		if nil != err {
			return
		}

		err = conn.SetReadDeadline(time.Now().Add(time.Duration(pingOption.GetDeadline()) * time.Second))
		if nil != err {
			return
		}
		bufLen, err = conn.Read(buf)
		if nil != err {
			return
		}

		err = _matcher.Match(matchCtx, indexM+1, osm.NewPacket(buf, bufLen))
		if nil != err {
			return
		}

		if packetCount-1 == indexM {
			return
		}
	}

	return
}