package service

import (
	"crypto/tls"
	"net"
	"strings"
	"time"

	omd "git.loafle.net/overflow/model/discovery"
	omm "git.loafle.net/overflow/model/meta"
	ounp "git.loafle.net/overflow/util-go/net/ping"
)

func Ping(service *omd.Service, pingOption ounp.Option) (ounp.Result, error) {
	if isDiscoveredByMatcher(service) {
		return processPing(service, pingOption, matcherPingFunc)
	}

	return processPing(service, pingOption, connectionPingFunc)
}

func isDiscoveredByMatcher(service *omd.Service) bool {
	for _, discoveredBy := range service.DiscoveredBy {
		switch omm.ToMetaDiscovererTypeEnum(discoveredBy) {
		case omm.MetaDiscovererTypeEnumUDPMatcher, omm.MetaDiscovererTypeEnumTCPMatcher:
			return true
		}
	}

	return false
}

type pingFunc func(service *omd.Service, pingOption ounp.Option) (ttl int, err error)

func processPing(service *omd.Service, pingOption ounp.Option, _pingFunc pingFunc) (ounp.Result, error) {
	responses := make(map[int]ounp.Response, 0)
	summary := &ounp.PingSummary{}

	pingResult := &ounp.PingResult{
		Responses: responses,
		Summary:   summary,
	}

	var _sum float64
	var _res *ounp.PingResponse

	for indexR := 0; indexR < pingOption.GetCount(); indexR++ {
		summary.SendCount = summary.SendCount + 1
		startTime := time.Now()

		_res = &ounp.PingResponse{}
		if 0 < indexR {
			select {
			case <-time.After(time.Duration(pingOption.GetDeadline()) * time.Second):
			}
		}

		ttl, err := _pingFunc(service, pingOption)
		elapsedTime := float64(time.Since(startTime).Nanoseconds()) / float64(1E6)

		if 0 == indexR {
			summary.MinTime = elapsedTime
			summary.MaxTime = elapsedTime
		}
		if nil == err {
			_sum = _sum + elapsedTime
			summary.ReceiveCount = summary.ReceiveCount + 1
			if summary.MinTime > elapsedTime {
				summary.MinTime = elapsedTime
			}

			if summary.MaxTime < elapsedTime {
				summary.MaxTime = elapsedTime
			}
			_res.Time = elapsedTime
			_res.TTL = ttl
		} else {
			_res.Error = err.Error()
		}
		pingResult.Responses[indexR] = _res
	}

	if 0 == summary.ReceiveCount {
		summary.AvgTime = 0
		summary.LossPercent = 100
	} else {
		summary.AvgTime = _sum / float64(summary.ReceiveCount)
		summary.LossPercent = (float32(summary.SendCount) - float32(summary.ReceiveCount)) / float32(summary.SendCount) * float32(100)
	}

	return pingResult, nil
}

func getConnection(service *omd.Service, pingOption ounp.Option) (net.Conn, error) {
	addr := net.JoinHostPort(service.Port.Host.Address, service.Port.PortNumber.String())
	portType := strings.ToLower(service.Port.MetaPortType.Key)

	switch omm.ToMetaCryptoTypeEnum(service.MetaCryptoType) {
	case omm.MetaCryptoTypeEnumTLS:
		dialer := &net.Dialer{
			Timeout: time.Duration(pingOption.GetDeadline()) * time.Second,
		}

		return tls.DialWithDialer(
			dialer,
			portType,
			addr,
			&tls.Config{
				InsecureSkipVerify: true,
				ServerName:         service.Port.Host.Address,
			},
		)
	default:

		return net.DialTimeout(portType, addr, time.Duration(pingOption.GetDeadline())*time.Second)
	}
}