loc-serv.go

/*
 * Copyright (c) 2019  InterDigital Communications, Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package server

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"net/url"
	"os"
	"strconv"
	"strings"
	"sync"
	"time"

	sbi "github.com/InterDigitalInc/AdvantEDGE/go-apps/meep-loc-serv/sbi"
	asc "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-app-support-client"
	dkm "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-data-key-mgr"
	gisClient "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-gis-engine-client"
	httpLog "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-http-logger"
	log "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-logger"
	met "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-metrics"
	redis "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-redis"
	scc "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-sandbox-ctrl-client"
	smc "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-service-mgmt-client"

	"github.com/gorilla/mux"
)

const moduleName = "meep-loc-serv"
const LocServBasePath = "location/v2/"
const locServKey = "loc-serv"
const serviceName = "Location Service"
const defaultMepName = "global"
const defaultScopeOfLocality = "MEC_SYSTEM"
const defaultConsumedLocalOnly = true

const typeZone = "zone"
const typeAccessPoint = "accessPoint"
const typeUser = "user"
const typeZonalSubscription = "zonalsubs"
const typeUserSubscription = "usersubs"
const typeZoneStatusSubscription = "zonestatus"
const typeDistanceSubscription = "distance"
const typeAreaCircleSubscription = "areacircle"
const typePeriodicSubscription = "periodic"

const (
	notifZonalPresence = "ZonalPresenceNotification"
	notifZoneStatus    = "ZoneStatusNotification"
	notifSubscription  = "SubscriptionNotification"
)

type UeUserData struct {
	queryZoneId  []string
	queryApId    []string
	queryAddress []string
	userList     *UserList
}

type ApUserData struct {
	queryInterestRealm string
	apList             *AccessPointList
}

type Pair struct {
	addr1 string
	addr2 string
}

var nextZonalSubscriptionIdAvailable int
var nextUserSubscriptionIdAvailable int
var nextZoneStatusSubscriptionIdAvailable int
var nextDistanceSubscriptionIdAvailable int
var nextAreaCircleSubscriptionIdAvailable int
var nextPeriodicSubscriptionIdAvailable int

var zonalSubscriptionEnteringMap = map[int]string{}
var zonalSubscriptionLeavingMap = map[int]string{}
var zonalSubscriptionTransferringMap = map[int]string{}
var zonalSubscriptionMap = map[int]string{}

var userSubscriptionEnteringMap = map[int]string{}
var userSubscriptionLeavingMap = map[int]string{}
var userSubscriptionTransferringMap = map[int]string{}
var userSubscriptionMap = map[int]string{}

var zoneStatusSubscriptionMap = map[int]*ZoneStatusCheck{}
var distanceSubscriptionMap = map[int]*DistanceCheck{}
var periodicTicker *time.Ticker
var areaCircleSubscriptionMap = map[int]*AreaCircleCheck{}
var periodicSubscriptionMap = map[int]*PeriodicCheck{}

var addressConnectedMap = map[string]bool{}

type ZoneStatusCheck struct {
	ZoneId                 string
	Serviceable            bool
	Unserviceable          bool
	Unknown                bool
	NbUsersInZoneThreshold int32
	NbUsersInAPThreshold   int32
}

type DistanceCheck struct {
	NextTts                int32 //next time to send, derived from frequency
	NbNotificationsSent    int32
	NotificationCheckReady bool
	Subscription           *DistanceNotificationSubscription
}

type AreaCircleCheck struct {
	NextTts                int32 //next time to send, derived from frequency
	AddrInArea             map[string]bool
	NbNotificationsSent    int32
	NotificationCheckReady bool
	Subscription           *CircleNotificationSubscription
}

type PeriodicCheck struct {
	NextTts      int32 //next time to send, derived from frequency
	Subscription *PeriodicNotificationSubscription
}

var LOC_SERV_DB = 0
var currentStoreName = ""

var redisAddr string = "meep-redis-master.default.svc.cluster.local:6379"
var influxAddr string = "http://meep-influxdb.default.svc.cluster.local:8086"
var sbxCtrlUrl string = "http://meep-sandbox-ctrl"

var rc *redis.Connector
var hostUrl *url.URL
var instanceId string
var instanceName string
var sandboxName string
var mepName string = defaultMepName
var scopeOfLocality string = defaultScopeOfLocality
var consumedLocalOnly bool = defaultConsumedLocalOnly
var locality []string
var basePath string
var baseKey string
var mutex sync.Mutex

var gisAppClient *gisClient.APIClient
var gisAppClientUrl string = "http://meep-gis-engine"

const serviceAppVersion = "2.1.1"

var serviceAppInstanceId string

var appEnablementUrl string
var appEnablementEnabled bool
var sendAppTerminationWhenDone bool = false
var appSupportClient *asc.APIClient
var svcMgmtClient *smc.APIClient
var sbxCtrlClient *scc.APIClient

var registrationTicker *time.Ticker

// Init - Location Service initialization
func Init() (err error) {

	// Retrieve Instance ID from environment variable if present
	instanceIdEnv := strings.TrimSpace(os.Getenv("MEEP_INSTANCE_ID"))
	if instanceIdEnv != "" {
		instanceId = instanceIdEnv
	}
	log.Info("MEEP_INSTANCE_ID: ", instanceId)

	// Retrieve Instance Name from environment variable
	instanceName = moduleName
	instanceNameEnv := strings.TrimSpace(os.Getenv("MEEP_POD_NAME"))
	if instanceNameEnv != "" {
		instanceName = instanceNameEnv
	}
	log.Info("MEEP_POD_NAME: ", instanceName)

	// Get Sandbox name
	sandboxNameEnv := strings.TrimSpace(os.Getenv("MEEP_SANDBOX_NAME"))
	if sandboxNameEnv != "" {
		sandboxName = sandboxNameEnv
	}
	if sandboxName == "" {
		err = errors.New("MEEP_SANDBOX_NAME env variable not set")
		log.Error(err.Error())
		return err
	}
	log.Info("MEEP_SANDBOX_NAME: ", sandboxName)

	// hostUrl is the url of the node serving the resourceURL
	// Retrieve public url address where service is reachable, if not present, use Host URL environment variable
	hostUrl, err = url.Parse(strings.TrimSpace(os.Getenv("MEEP_PUBLIC_URL")))
	if err != nil || hostUrl == nil || hostUrl.String() == "" {
		hostUrl, err = url.Parse(strings.TrimSpace(os.Getenv("MEEP_HOST_URL")))
		if err != nil {
			hostUrl = new(url.URL)
		}
	}
	log.Info("MEEP_HOST_URL: ", hostUrl)

	// Get MEP name
	mepNameEnv := strings.TrimSpace(os.Getenv("MEEP_MEP_NAME"))
	if mepNameEnv != "" {
		mepName = mepNameEnv
	}
	log.Info("MEEP_MEP_NAME: ", mepName)

	// Get App Enablement URL
	appEnablementEnabled = false
	appEnablementEnv := strings.TrimSpace(os.Getenv("MEEP_APP_ENABLEMENT"))
	if appEnablementEnv != "" {
		appEnablementUrl = "http://" + appEnablementEnv
		appEnablementEnabled = true
	}
	log.Info("MEEP_APP_ENABLEMENT: ", appEnablementUrl)

	// Get scope of locality
	scopeOfLocalityEnv := strings.TrimSpace(os.Getenv("MEEP_SCOPE_OF_LOCALITY"))
	if scopeOfLocalityEnv != "" {
		scopeOfLocality = scopeOfLocalityEnv
	}
	log.Info("MEEP_SCOPE_OF_LOCALITY: ", scopeOfLocality)

	// Get local consumption
	consumedLocalOnlyEnv := strings.TrimSpace(os.Getenv("MEEP_CONSUMED_LOCAL_ONLY"))
	if consumedLocalOnlyEnv != "" {
		value, err := strconv.ParseBool(consumedLocalOnlyEnv)
		if err == nil {
			consumedLocalOnly = value
		}
	}
	log.Info("MEEP_CONSUMED_LOCAL_ONLY: ", consumedLocalOnly)

	// Get locality
	localityEnv := strings.TrimSpace(os.Getenv("MEEP_LOCALITY"))
	if localityEnv != "" {
		locality = strings.Split(localityEnv, ":")
	}
	log.Info("MEEP_LOCALITY: ", locality)

	// Set base path
	if mepName == defaultMepName {
		basePath = "/" + sandboxName + "/" + LocServBasePath
	} else {
		basePath = "/" + sandboxName + "/" + mepName + "/" + LocServBasePath
	}

	// Set base storage key
	baseKey = dkm.GetKeyRoot(sandboxName) + locServKey + ":mep:" + mepName + ":"

	// Connect to Redis DB
	rc, err = redis.NewConnector(redisAddr, LOC_SERV_DB)
	if err != nil {
		log.Error("Failed connection to Redis DB. Error: ", err)
		return err
	}
	_ = rc.DBFlush(baseKey)
	log.Info("Connected to Redis DB, location service table")

	gisAppClientCfg := gisClient.NewConfiguration()
	gisAppClientCfg.BasePath = gisAppClientUrl + "/gis/v1"

	gisAppClient = gisClient.NewAPIClient(gisAppClientCfg)
	if gisAppClient == nil {
		log.Error("Failed to create GIS App REST API client: ", gisAppClientCfg.BasePath)
		err := errors.New("Failed to create GIS App REST API client")
		return err
	}

	userTrackingReInit()
	zonalTrafficReInit()
	zoneStatusReInit()
	distanceReInit()
	areaCircleReInit()
	periodicReInit()

	// Initialize SBI
	sbiCfg := sbi.SbiCfg{
		SandboxName:    sandboxName,
		RedisAddr:      redisAddr,
		Locality:       locality,
		UserInfoCb:     updateUserInfo,
		ZoneInfoCb:     updateZoneInfo,
		ApInfoCb:       updateAccessPointInfo,
		ScenarioNameCb: updateStoreName,
		CleanUpCb:      cleanUp,
	}
	err = sbi.Init(sbiCfg)
	if err != nil {
		log.Error("Failed initialize SBI. Error: ", err)
		return err
	}
	log.Info("SBI Initialized")

	// Create App Enablement REST clients
	if appEnablementEnabled {
		// Create App Info client
		sbxCtrlClientCfg := scc.NewConfiguration()
		sbxCtrlClientCfg.BasePath = sbxCtrlUrl + "/sandbox-ctrl/v1"
		sbxCtrlClient = scc.NewAPIClient(sbxCtrlClientCfg)
		if sbxCtrlClient == nil {
			return errors.New("Failed to create App Info REST API client")
		}

		// Create App Support client
		appSupportClientCfg := asc.NewConfiguration()
		appSupportClientCfg.BasePath = appEnablementUrl + "/mec_app_support/v1"
		appSupportClient = asc.NewAPIClient(appSupportClientCfg)
		if appSupportClient == nil {
			return errors.New("Failed to create App Enablement App Support REST API client")
		}

		// Create Service Management client
		srvMgmtClientCfg := smc.NewConfiguration()
		srvMgmtClientCfg.BasePath = appEnablementUrl + "/mec_service_mgmt/v1"
		svcMgmtClient = smc.NewAPIClient(srvMgmtClientCfg)
		if svcMgmtClient == nil {
			return errors.New("Failed to create App Enablement Service Management REST API client")
		}
	}

	log.Info("Location Service successfully initialized")
	return nil
}

// Run - Start Location Service
func Run() (err error) {

	// Start MEC Service registration ticker
	if appEnablementEnabled {
		startRegistrationTicker()
	}

	periodicTicker = time.NewTicker(time.Second)
	go func() {
		for range periodicTicker.C {
			checkNotificationDistancePeriodicTrigger()
			updateNotificationAreaCirclePeriodicTrigger()
			checkNotificationPeriodicTrigger()
		}
	}()

	return sbi.Run()
}

// Stop - Stop Location
func Stop() (err error) {
	// Stop MEC Service registration ticker
	if appEnablementEnabled {
		stopRegistrationTicker()
		if sendAppTerminationWhenDone {
			err = sendTerminationConfirmation(serviceAppInstanceId)
			if err != nil {
				return err
			}
		}
	}

	periodicTicker.Stop()
	err = sbi.Stop()
	if err != nil {
		return err
	}
	return nil
}

func startRegistrationTicker() {
	// Make sure ticker is not running
	if registrationTicker != nil {
		log.Warn("Registration ticker already running")
		return
	}

	// Wait a few seconds to allow App Enablement Service to start.
	// This is done to avoid the default 20 second TCP socket connect timeout
	// if the App Enablement Service is not yet running.
	log.Info("Waiting for App Enablement Service to start")
	time.Sleep(5 * time.Second)

	// Start registration ticker
	registrationTicker = time.NewTicker(5 * time.Second)
	go func() {
		mecAppReadySent := false
		// registrationSent := false
		for range registrationTicker.C {
			// Get Application instance ID if not already available
			if serviceAppInstanceId == "" {
				var err error
				serviceAppInstanceId, err = getAppInstanceId()
				if err != nil || serviceAppInstanceId == "" {
					continue
				}
			}

			// Send App Ready message
			if !mecAppReadySent {
				err := sendReadyConfirmation(serviceAppInstanceId)
				if err != nil {
					log.Error("Failure when sending the MecAppReady message. Error: ", err)
					continue
				}
				mecAppReadySent = true
			}

			// Register service instance
			// if !registrationSent {
			err := registerService(serviceAppInstanceId)
			if err != nil {
				log.Error("Failed to register to appEnablement DB, keep trying. Error: ", err)
				continue
			}
			// 	registrationSent = true
			// }

			// // Register for graceful termination
			// if !subscriptionSent {
			// 	err = subscribeAppTermination(serviceAppInstanceId)
			// 	if err != nil {
			// 		log.Error("Failed to subscribe to graceful termination. Error: ", err)
			// 		continue
			// 	}
			// 	sendAppTerminationWhenDone = true
			// 	subscriptionSent = true
			// }

			// Registration complete
			log.Info("Successfully registered with App Enablement Service")
			stopRegistrationTicker()
			return
		}
	}()
}

func stopRegistrationTicker() {
	if registrationTicker != nil {
		log.Info("Stopping App Enablement registration ticker")
		registrationTicker.Stop()
		registrationTicker = nil
	}
}

func getAppInstanceId() (id string, err error) {
	var appInfo scc.ApplicationInfo
	appInfo.Id = instanceId
	appInfo.Name = instanceName
	appInfo.MepName = mepName
	appInfo.Version = serviceAppVersion
	appType := scc.SYSTEM_ApplicationType
	appInfo.Type_ = &appType
	state := scc.INITIALIZED_ApplicationState
	appInfo.State = &state
	response, _, err := sbxCtrlClient.ApplicationsApi.ApplicationsPOST(context.TODO(), appInfo)
	if err != nil {
		log.Error("Failed to get App Instance ID with error: ", err)
		return "", err
	}
	return response.Id, nil
}

func registerService(appInstanceId string) error {
	var srvInfo smc.ServiceInfoPost
	//serName
	srvInfo.SerName = instanceName
	//version
	srvInfo.Version = serviceAppVersion
	//state
	state := smc.ACTIVE_ServiceState
	srvInfo.State = &state
	//serializer
	serializer := smc.JSON_SerializerType
	srvInfo.Serializer = &serializer

	//transportInfo
	var transportInfo smc.TransportInfo
	transportInfo.Id = "transport"
	transportInfo.Name = "REST"
	transportType := smc.REST_HTTP_TransportType
	transportInfo.Type_ = &transportType
	transportInfo.Protocol = "HTTP"
	transportInfo.Version = "2.0"
	var endpoint smc.OneOfTransportInfoEndpoint
	endpointPath := hostUrl.String() + basePath
	endpoint.Uris = append(endpoint.Uris, endpointPath)
	transportInfo.Endpoint = &endpoint
	srvInfo.TransportInfo = &transportInfo

	//serCategory
	var category smc.CategoryRef
	category.Href = "catalogueHref"
	category.Id = "locationId"
	category.Name = "Location"
	category.Version = "v2"
	srvInfo.SerCategory = &category

	//scopeOfLocality
	localityType := smc.LocalityType(scopeOfLocality)
	srvInfo.ScopeOfLocality = &localityType

	//consumedLocalOnly
	srvInfo.ConsumedLocalOnly = consumedLocalOnly

	appServicesPostResponse, _, err := svcMgmtClient.AppServicesApi.AppServicesPOST(context.TODO(), srvInfo, appInstanceId)
	if err != nil {
		log.Error("Failed to register the service to app enablement registry: ", err)
		return err
	}
	log.Info("Application Enablement Service instance Id: ", appServicesPostResponse.SerInstanceId)
	return nil
}

func sendReadyConfirmation(appInstanceId string) error {
	var appReady asc.AppReadyConfirmation
	indication := asc.READY_ReadyIndicationType
	appReady.Indication = &indication
	_, err := appSupportClient.AppConfirmReadyApi.ApplicationsConfirmReadyPOST(context.TODO(), appReady, appInstanceId)
	if err != nil {
		log.Error("Failed to send a ready confirm acknowlegement: ", err)
		return err
	}
	return nil
}

func sendTerminationConfirmation(appInstanceId string) error {
	var appTermination asc.AppTerminationConfirmation
	operationAction := asc.TERMINATING_OperationActionType
	appTermination.OperationAction = &operationAction
	_, err := appSupportClient.AppConfirmTerminationApi.ApplicationsConfirmTerminationPOST(context.TODO(), appTermination, appInstanceId)
	if err != nil {
		log.Error("Failed to send a confirm termination acknowlegement: ", err)
		return err
	}
	return nil
}

// func subscribeAppTermination(appInstanceId string) error {
// 	var subscription asc.AppTerminationNotificationSubscription
// 	subscription.SubscriptionType = "AppTerminationNotificationSubscription"
// 	subscription.AppInstanceId = appInstanceId
// 	subscription.CallbackReference = hostUrl.String() + basePath
// 	_, _, err := appSupportClient.AppSubscriptionsApi.ApplicationsSubscriptionsPOST(context.TODO(), subscription, appInstanceId)
// 	if err != nil {
// 		log.Error("Failed to register to App Support subscription: ", err)
// 		return err
// 	}
// 	return nil
// }

func deregisterZoneStatus(subsIdStr string) {
	subsId, err := strconv.Atoi(subsIdStr)
	if err != nil {
		log.Error(err)
	}

	mutex.Lock()
	defer mutex.Unlock()
	zoneStatusSubscriptionMap[subsId] = nil
}

func registerZoneStatus(zoneId string, nbOfUsersZoneThreshold int32, nbOfUsersAPThreshold int32, opStatus []OperationStatus, subsIdStr string) {

	subsId, err := strconv.Atoi(subsIdStr)
	if err != nil {
		log.Error(err)
	}

	var zoneStatus ZoneStatusCheck
	if opStatus != nil {
		for i := 0; i < len(opStatus); i++ {
			switch opStatus[i] {
			case SERVICEABLE:
				zoneStatus.Serviceable = true
			case UNSERVICEABLE:
				zoneStatus.Unserviceable = true
			case OPSTATUS_UNKNOWN:
				zoneStatus.Unknown = true
			default:
			}
		}
	}
	zoneStatus.NbUsersInZoneThreshold = nbOfUsersZoneThreshold
	zoneStatus.NbUsersInAPThreshold = nbOfUsersAPThreshold
	zoneStatus.ZoneId = zoneId
	mutex.Lock()
	defer mutex.Unlock()
	zoneStatusSubscriptionMap[subsId] = &zoneStatus
}

func deregisterZonal(subsIdStr string) {
	subsId, err := strconv.Atoi(subsIdStr)
	if err != nil {
		log.Error(err)
	}

	mutex.Lock()
	defer mutex.Unlock()
	zonalSubscriptionMap[subsId] = ""
	zonalSubscriptionEnteringMap[subsId] = ""
	zonalSubscriptionLeavingMap[subsId] = ""
	zonalSubscriptionTransferringMap[subsId] = ""
}

func registerZonal(zoneId string, event []UserEventType, subsIdStr string) {

	subsId, err := strconv.Atoi(subsIdStr)
	if err != nil {
		log.Error(err)
	}

	mutex.Lock()
	defer mutex.Unlock()
	if event != nil {
		for i := 0; i < len(event); i++ {
			switch event[i] {
			case ENTERING_EVENT:
				zonalSubscriptionEnteringMap[subsId] = zoneId
			case LEAVING_EVENT:
				zonalSubscriptionLeavingMap[subsId] = zoneId
			case TRANSFERRING_EVENT:
				zonalSubscriptionTransferringMap[subsId] = zoneId
			default:
			}
		}
	} else {
		zonalSubscriptionEnteringMap[subsId] = zoneId
		zonalSubscriptionLeavingMap[subsId] = zoneId
		zonalSubscriptionTransferringMap[subsId] = zoneId
	}
	zonalSubscriptionMap[subsId] = zoneId
}

func deregisterUser(subsIdStr string) {
	subsId, err := strconv.Atoi(subsIdStr)
	if err != nil {
		log.Error(err)
	}

	mutex.Lock()
	defer mutex.Unlock()
	userSubscriptionMap[subsId] = ""
	userSubscriptionEnteringMap[subsId] = ""
	userSubscriptionLeavingMap[subsId] = ""
	userSubscriptionTransferringMap[subsId] = ""
}

func registerUser(userAddress string, event []UserEventType, subsIdStr string) {

	subsId, err := strconv.Atoi(subsIdStr)
	if err != nil {
		log.Error(err)
	}

	mutex.Lock()
	defer mutex.Unlock()
	if event != nil {
		for i := 0; i < len(event); i++ {
			switch event[i] {
			case ENTERING_EVENT:
				userSubscriptionEnteringMap[subsId] = userAddress
			case LEAVING_EVENT:
				userSubscriptionLeavingMap[subsId] = userAddress
			case TRANSFERRING_EVENT:
				userSubscriptionTransferringMap[subsId] = userAddress
			default:
			}
		}
	} else {
		userSubscriptionEnteringMap[subsId] = userAddress
		userSubscriptionLeavingMap[subsId] = userAddress
		userSubscriptionTransferringMap[subsId] = userAddress
	}
	userSubscriptionMap[subsId] = userAddress
}

func updateNotificationAreaCirclePeriodicTrigger() {
	//only check if there is at least one subscription
	mutex.Lock()
	defer mutex.Unlock()

	for _, areaCircleCheck := range areaCircleSubscriptionMap {
		if areaCircleCheck != nil {
			if areaCircleCheck.NextTts != 0 {
				areaCircleCheck.NextTts--
			}
			if areaCircleCheck.NextTts == 0 {
				areaCircleCheck.NotificationCheckReady = true
			} else {
				areaCircleCheck.NotificationCheckReady = false
			}
		}
	}
}

func checkNotificationDistancePeriodicTrigger() {

	//only check if there is at least one subscription
	mutex.Lock()
	defer mutex.Unlock()
	//check all that applies
	for subsId, distanceCheck := range distanceSubscriptionMap {
		if distanceCheck != nil && distanceCheck.Subscription != nil {
			if distanceCheck.Subscription.Count == 0 || (distanceCheck.Subscription.Count != 0 && distanceCheck.NbNotificationsSent < distanceCheck.Subscription.Count) {
				if distanceCheck.NextTts != 0 {
					distanceCheck.NextTts--
				}
				if distanceCheck.NextTts == 0 {
					distanceCheck.NotificationCheckReady = true
				} else {
					distanceCheck.NotificationCheckReady = false
				}

				if !distanceCheck.NotificationCheckReady {
					continue
				}

				//loop through every reference address
				returnAddr := make(map[string]*gisClient.Distance)
				skipThisSubscription := false

				//if reference address is specified, reference addresses are checked agains each monitored address
				//if reference address is nil, each pair of the monitored address should be checked
				//creating address pairs to check
				//e.g. refAddr = A, B ; monitoredAddr = C, D, E ; resultingPairs {A,C - A,D - A,E - B,C - B,D - B-E}
				//e.g. monitoredAddr = A, B, C ; resultingPairs {A,B - B,A - A,C - C,A - B,C - C,B}

				var addressPairs []Pair
				if distanceCheck.Subscription.ReferenceAddress != nil {
					for _, refAddr := range distanceCheck.Subscription.ReferenceAddress {
						//loop through every monitored address
						for _, monitoredAddr := range distanceCheck.Subscription.MonitoredAddress {
							pair := Pair{addr1: refAddr, addr2: monitoredAddr}
							addressPairs = append(addressPairs, pair)
						}
					}
				} else {
					nbIndex := len(distanceCheck.Subscription.MonitoredAddress)
					for i := 0; i < nbIndex-1; i++ {
						for j := i + 1; j < nbIndex; j++ {
							pair := Pair{addr1: distanceCheck.Subscription.MonitoredAddress[i], addr2: distanceCheck.Subscription.MonitoredAddress[j]}
							addressPairs = append(addressPairs, pair)
							//need pair to be symmetrical so that each is used as reference point and monitored address
							pair = Pair{addr1: distanceCheck.Subscription.MonitoredAddress[j], addr2: distanceCheck.Subscription.MonitoredAddress[i]}
							addressPairs = append(addressPairs, pair)
						}
					}
				}

				for _, pair := range addressPairs {
					refAddr := pair.addr1
					monitoredAddr := pair.addr2

					//check if one of the address if both addresses are connected, if not, disregard this pair
					if !addressConnectedMap[refAddr] || !addressConnectedMap[monitoredAddr] {
						//ignore that pair and continue processing
						continue
					}

					var distParam gisClient.TargetPoint
					distParam.AssetName = monitoredAddr

					distResp, httpResp, err := gisAppClient.GeospatialDataApi.GetDistanceGeoDataByName(context.TODO(), refAddr, distParam)
					if err != nil {
						//getting distance of an element that is not in the DB (not in scenario, not connected) returns error code 400 (bad parameters) in the API. Using that error code to track that request made it to GIS but no good result, so ignore that address (monitored or ref)
						if httpResp.StatusCode == http.StatusBadRequest {
							//ignore that pair and continue processing
							continue
						} else {
							log.Error("Failed to communicate with gis engine: ", err)
							return
						}
					}

					distance := int32(distResp.Distance)

					switch *distanceCheck.Subscription.Criteria {
					case ALL_WITHIN_DISTANCE:
						if float32(distance) < distanceCheck.Subscription.Distance {
							returnAddr[monitoredAddr] = &distResp
						} else {
							skipThisSubscription = true
						}
					case ALL_BEYOND_DISTANCE:
						if float32(distance) > distanceCheck.Subscription.Distance {
							returnAddr[monitoredAddr] = &distResp
						} else {
							skipThisSubscription = true
						}
					case ANY_WITHIN_DISTANCE:
						if float32(distance) < distanceCheck.Subscription.Distance {
							returnAddr[monitoredAddr] = &distResp
						}
					case ANY_BEYOND_DISTANCE:
						if float32(distance) > distanceCheck.Subscription.Distance {
							returnAddr[monitoredAddr] = &distResp
						}
					default:
					}
					if skipThisSubscription {
						break
					}
				}
				if skipThisSubscription {
					continue
				}
				if len(returnAddr) > 0 {
					//update nb of notification sent anch check if valid
					subsIdStr := strconv.Itoa(subsId)

					var distanceNotif SubscriptionNotification
					distanceNotif.DistanceCriteria = distanceCheck.Subscription.Criteria
					distanceNotif.IsFinalNotification = false
					distanceNotif.Link = distanceCheck.Subscription.Link
					var terminalLocationList []TerminalLocation
					for terminalAddr, distanceInfo := range returnAddr {
						var terminalLocation TerminalLocation
						terminalLocation.Address = terminalAddr
						var locationInfo LocationInfo
						locationInfo.Latitude = nil
						locationInfo.Latitude = append(locationInfo.Latitude, distanceInfo.DstLatitude)
						locationInfo.Longitude = nil
						locationInfo.Longitude = append(locationInfo.Longitude, distanceInfo.DstLongitude)
						locationInfo.Shape = 2
						seconds := time.Now().Unix()
						var timestamp TimeStamp
						timestamp.Seconds = int32(seconds)
						locationInfo.Timestamp = &timestamp
						terminalLocation.CurrentLocation = &locationInfo
						retrievalStatus := RETRIEVED
						terminalLocation.LocationRetrievalStatus = &retrievalStatus
						terminalLocationList = append(terminalLocationList, terminalLocation)
					}
					distanceNotif.TerminalLocation = terminalLocationList
					distanceNotif.CallbackData = distanceCheck.Subscription.CallbackReference.CallbackData
					var inlineDistanceSubscriptionNotification InlineSubscriptionNotification
					inlineDistanceSubscriptionNotification.SubscriptionNotification = &distanceNotif
					distanceCheck.NbNotificationsSent++
					sendSubscriptionNotification(distanceCheck.Subscription.CallbackReference.NotifyURL, inlineDistanceSubscriptionNotification)
					log.Info("Distance Notification"+"("+subsIdStr+") For ", returnAddr)
					distanceSubscriptionMap[subsId].NextTts = distanceCheck.Subscription.Frequency
					distanceSubscriptionMap[subsId].NotificationCheckReady = false
				}
			}
		}
	}
}

func checkNotificationAreaCircle(addressToCheck string) {
	//only check if there is at least one subscription
	mutex.Lock()
	defer mutex.Unlock()
	//check all that applies
	for subsId, areaCircleCheck := range areaCircleSubscriptionMap {
		if areaCircleCheck != nil && areaCircleCheck.Subscription != nil {
			if areaCircleCheck.Subscription.Count == 0 || (areaCircleCheck.Subscription.Count != 0 && areaCircleCheck.NbNotificationsSent < areaCircleCheck.Subscription.Count) {
				if !areaCircleCheck.NotificationCheckReady {
					continue
				}

				//loop through every reference address
				for _, addr := range areaCircleCheck.Subscription.Address {
					if addr != addressToCheck {
						continue
					}
					if !addressConnectedMap[addr] {
						continue
					}
					//check if address is already inside the area or not based on the subscription
					var withinRangeParam gisClient.TargetRange
					withinRangeParam.Latitude = areaCircleCheck.Subscription.Latitude
					withinRangeParam.Longitude = areaCircleCheck.Subscription.Longitude
					withinRangeParam.Radius = areaCircleCheck.Subscription.Radius

					withinRangeResp, httpResp, err := gisAppClient.GeospatialDataApi.GetWithinRangeByName(context.TODO(), addr, withinRangeParam)
					if err != nil {
						//getting element that is not in the DB (not in scenario, not connected) returns error code 400 (bad parameters) in the API. Using that error code to track that request made it to GIS but no good result, so ignore that address (monitored or ref)
						if httpResp.StatusCode == http.StatusBadRequest {
							//if the UE was within the zone, continue processing to send a LEAVING notification, otherwise, go to next subscription
							if !areaCircleCheck.AddrInArea[addr] {
								continue
							}
						} else {
							log.Error("Failed to communicate with gis engine: ", err)
							return
						}
					}
					//check if there is a change
					var event EnteringLeavingCriteria
					if withinRangeResp.Within {
						if areaCircleCheck.AddrInArea[addr] {
							//no change
							continue
						} else {
							areaCircleCheck.AddrInArea[addr] = true
							event = ENTERING_CRITERIA
						}
					} else {
						if !areaCircleCheck.AddrInArea[addr] {
							//no change
							continue
						} else {
							areaCircleCheck.AddrInArea[addr] = false
							event = LEAVING_CRITERIA
						}
					}
					//no tracking this event, stop looking for this UE
					if *areaCircleCheck.Subscription.EnteringLeavingCriteria != event {
						continue
					}
					subsIdStr := strconv.Itoa(subsId)
					var areaCircleNotif SubscriptionNotification

					areaCircleNotif.EnteringLeavingCriteria = areaCircleCheck.Subscription.EnteringLeavingCriteria
					areaCircleNotif.IsFinalNotification = false
					areaCircleNotif.Link = areaCircleCheck.Subscription.Link
					var terminalLocationList []TerminalLocation
					var terminalLocation TerminalLocation
					terminalLocation.Address = addr
					var locationInfo LocationInfo
					locationInfo.Latitude = nil
					locationInfo.Latitude = append(locationInfo.Latitude, withinRangeResp.SrcLatitude)
					locationInfo.Longitude = nil
					locationInfo.Longitude = append(locationInfo.Longitude, withinRangeResp.SrcLongitude)
					locationInfo.Shape = 2
					seconds := time.Now().Unix()
					var timestamp TimeStamp
					timestamp.Seconds = int32(seconds)
					locationInfo.Timestamp = &timestamp
					terminalLocation.CurrentLocation = &locationInfo
					retrievalStatus := RETRIEVED
					terminalLocation.LocationRetrievalStatus = &retrievalStatus
					terminalLocationList = append(terminalLocationList, terminalLocation)

					areaCircleNotif.TerminalLocation = terminalLocationList
					areaCircleNotif.CallbackData = areaCircleCheck.Subscription.CallbackReference.CallbackData
					var inlineCircleSubscriptionNotification InlineSubscriptionNotification
					inlineCircleSubscriptionNotification.SubscriptionNotification = &areaCircleNotif
					areaCircleCheck.NbNotificationsSent++
					sendSubscriptionNotification(areaCircleCheck.Subscription.CallbackReference.NotifyURL, inlineCircleSubscriptionNotification)
					log.Info("Area Circle Notification" + "(" + subsIdStr + ") For " + addr + " when " + string(*areaCircleCheck.Subscription.EnteringLeavingCriteria) + " area")
					areaCircleSubscriptionMap[subsId].NextTts = areaCircleCheck.Subscription.Frequency
					areaCircleSubscriptionMap[subsId].NotificationCheckReady = false
				}
			}
		}
	}
}

func checkNotificationPeriodicTrigger() {

	//only check if there is at least one subscription
	mutex.Lock()
	defer mutex.Unlock()

	//check all that applies
	for subsId, periodicCheck := range periodicSubscriptionMap {
		if periodicCheck != nil && periodicCheck.Subscription != nil {
			//decrement the next time to send a message
			periodicCheck.NextTts--
			if periodicCheck.NextTts > 0 {
				continue
			} else { //restart the nextTts and continue processing to send notification or not
				periodicCheck.NextTts = periodicCheck.Subscription.Frequency
			}

			//loop through every reference address
			var terminalLocationList []TerminalLocation
			var periodicNotif SubscriptionNotification

			for _, addr := range periodicCheck.Subscription.Address {

				if !addressConnectedMap[addr] {
					continue
				}

				geoDataInfo, _, err := gisAppClient.GeospatialDataApi.GetGeoDataByName(context.TODO(), addr, nil)
				if err != nil {
					log.Error("Failed to communicate with gis engine: ", err)
					return
				}

				var terminalLocation TerminalLocation
				terminalLocation.Address = addr
				var locationInfo LocationInfo