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"
	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"

	"github.com/gorilla/mux"
)

const LocServBasePath = "/location/v2/"
const locServKey = "loc-serv:"
const logModuleLocServ = "meep-loc-serv"
const serviceName = "Location Service"

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 (
	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 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 distancePeriodicTicker *time.Ticker

var areaCircleSubscriptionMap = map[int]*AreaCircleCheck{}

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
	Subscription *DistanceNotificationSubscription
}

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

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 rc *redis.Connector
var hostUrl *url.URL
var sandboxName string
var basePath string
var baseKey string
var mutex sync.Mutex

var gisAppClient *gisClient.APIClient

func notImplemented(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json; charset=UTF-8")
	w.WriteHeader(http.StatusNotImplemented)
}

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

	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("resource URL: ", hostUrl)

	// Set base path
	basePath = "/" + sandboxName + LocServBasePath

	// Get base storage key
	baseKey = dkm.GetKeyRoot(sandboxName) + locServKey

	// 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 = hostUrl.String() + "/" + sandboxName + "/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()

	// Initialize SBI
	sbiCfg := sbi.SbiCfg{
		SandboxName:    sandboxName,
		RedisAddr:      redisAddr,
		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")

	return nil
}

// Run - Start Location Service
func Run() (err error) {
        distancePeriodicTicker = time.NewTicker(time.Second)
        go func() {
                for range distancePeriodicTicker.C {
                        checkNotificationDistancePeriodicTrigger()
                }
        }()

	return sbi.Run()
}

// Stop - Stop RNIS
func Stop() (err error) {
	distancePeriodicTicker.Stop()
	return sbi.Stop()
}

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 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 {
			//decrement the next time to send a message
			distanceCheck.NextTts--
			if distanceCheck.NextTts > 0 {
				continue
			} else { //restart the nextTts and continue processing to send notification or not
				distanceCheck.NextTts = distanceCheck.Subscription.Frequency
			}
			//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

				var distParam gisClient.TargetPoint
				distParam.AssetName = monitoredAddr

				distResp, _, err := gisAppClient.GeospatialDataApi.GetDistanceGeoDataByName(context.TODO(), refAddr, distParam)
				if err != nil {
					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 {
				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.Latitude)
					locationInfo.Longitude = nil
					locationInfo.Longitude = append(locationInfo.Longitude, distanceInfo.Longitude)
					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.ClientCorrelator
				var inlineDistanceSubscriptionNotification InlineSubscriptionNotification
				inlineDistanceSubscriptionNotification.SubscriptionNotification = &distanceNotif
				sendSubscriptionNotification(distanceCheck.Subscription.CallbackReference.NotifyURL, inlineDistanceSubscriptionNotification)
				log.Info("Distance Notification"+"("+subsIdStr+") For ", returnAddr)
			}
		}
	}
}

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 {
			//ignoring the frequency and checkImmediate for this subscription since it is considered event based, not periodic
			/* //decrement the next time to send a message
			if areaCircleCheck.NextTts > 0 {
				continue
			} else { //restart the nextTts and continue processing to send notification or not
				areaCircleCheck.NextTts = areaCircleCheck.Subscription.Frequency
			}*/

			//loop through every reference address
			for _, addr := range areaCircleCheck.Subscription.Address {
				if addr != addressToCheck {
					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, _, err := gisAppClient.GeospatialDataApi.GetWithinRangeByName(context.TODO(), addr, withinRangeParam)
				if err != nil {
					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.Latitude)
				locationInfo.Longitude = nil
				locationInfo.Longitude = append(locationInfo.Longitude, withinRangeResp.Longitude)
				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.ClientCorrelator
				var inlineCircleSubscriptionNotification InlineSubscriptionNotification
				inlineCircleSubscriptionNotification.SubscriptionNotification = &areaCircleNotif
				sendSubscriptionNotification(areaCircleCheck.Subscription.CallbackReference.NotifyURL, inlineCircleSubscriptionNotification)
				log.Info("Area Circle Notification" + "(" + subsIdStr + ") For " + addr + " when " + string(*areaCircleCheck.Subscription.EnteringLeavingCriteria) + " area")
			}

		}
	}
}

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

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

func registerDistance(distanceSub *DistanceNotificationSubscription, subsIdStr string) {

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

	mutex.Lock()
	defer mutex.Unlock()
	var distanceCheck DistanceCheck
	distanceCheck.Subscription = distanceSub
	if distanceSub.CheckImmediate {
		distanceCheck.NextTts = 0 //next time periodic trigger hits, will be forced to trigger
	} else {
		distanceCheck.NextTts = distanceSub.Frequency
	}
	distanceSubscriptionMap[subsId] = &distanceCheck
}

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

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

func registerAreaCircle(areaCircleSub *CircleNotificationSubscription, subsIdStr string) {

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

	mutex.Lock()
	defer mutex.Unlock()
	var areaCircleCheck AreaCircleCheck
	areaCircleCheck.Subscription = areaCircleSub
	areaCircleCheck.AddrInArea = map[string]bool{}
	//checkImmediate and NextTts apply more to a periodic notification, setting them but ignoring both in notification code because of unclear spec on that matter
	if areaCircleSub.CheckImmediate {
		areaCircleCheck.NextTts = 0 //next time periodic trigger hits, will be forced to trigger
	} else {
		areaCircleCheck.NextTts = areaCircleSub.Frequency
	}
	areaCircleSubscriptionMap[subsId] = &areaCircleCheck
}

func checkNotificationRegisteredZoneStatus(zoneId string, apId string, nbUsersInAP int32, nbUsersInZone int32, previousNbUsersInAP int32, previousNbUsersInZone int32) {

	mutex.Lock()
	defer mutex.Unlock()

	//check all that applies
	for subsId, zoneStatus := range zoneStatusSubscriptionMap {
		if zoneStatus == nil {
			continue
		}

		if zoneStatus.ZoneId == zoneId {
			zoneWarning := false
			apWarning := false
			if nbUsersInZone != -1 {
				if previousNbUsersInZone != nbUsersInZone && nbUsersInZone >= zoneStatus.NbUsersInZoneThreshold {
					zoneWarning = true
				}
			}
			if nbUsersInAP != -1 {
				if previousNbUsersInAP != nbUsersInAP && nbUsersInAP >= zoneStatus.NbUsersInAPThreshold {
					apWarning = true
				}
			}

			if zoneWarning || apWarning {
				subsIdStr := strconv.Itoa(subsId)
				jsonInfo, _ := rc.JSONGetEntry(baseKey+typeZoneStatusSubscription+":"+subsIdStr, ".")
				if jsonInfo == "" {
					return
				}

				subscription := convertJsonToZoneStatusSubscription(jsonInfo)

				var zoneStatusNotif ZoneStatusNotification
				zoneStatusNotif.ZoneId = zoneId
				if apWarning {
					zoneStatusNotif.AccessPointId = apId
					zoneStatusNotif.NumberOfUsersInAP = nbUsersInAP
				}
				if zoneWarning {
					zoneStatusNotif.NumberOfUsersInZone = nbUsersInZone
				}
				seconds := time.Now().Unix()
				var timestamp TimeStamp
				timestamp.Seconds = int32(seconds)
				zoneStatusNotif.Timestamp = &timestamp
				var inlineZoneStatusNotification InlineZoneStatusNotification
				inlineZoneStatusNotification.ZoneStatusNotification = &zoneStatusNotif
				sendStatusNotification(subscription.CallbackReference.NotifyURL, inlineZoneStatusNotification)
				if apWarning {
					log.Info("Zone Status Notification" + "(" + subsIdStr + "): " + "For event in zone " + zoneId + " which has " + strconv.Itoa(int(nbUsersInAP)) + " users in AP " + apId)
				} else {
					log.Info("Zone Status Notification" + "(" + subsIdStr + "): " + "For event in zone " + zoneId + " which has " + strconv.Itoa(int(nbUsersInZone)) + " users in total")
				}
			}
		}
	}
}

func checkNotificationRegisteredUsers(oldZoneId string, newZoneId string, oldApId string, newApId string, userId string) {

	mutex.Lock()
	defer mutex.Unlock()
	//check all that applies
	for subsId, value := range userSubscriptionMap {
		if value == userId {

			subsIdStr := strconv.Itoa(subsId)
			jsonInfo, _ := rc.JSONGetEntry(baseKey+typeUserSubscription+":"+subsIdStr, ".")
			if jsonInfo == "" {
				return
			}

			subscription := convertJsonToUserSubscription(jsonInfo)

			var zonal ZonalPresenceNotification
			zonal.Address = userId
			seconds := time.Now().Unix()
			var timestamp TimeStamp
			timestamp.Seconds = int32(seconds)
			zonal.Timestamp = &timestamp

			zonal.CallbackData = subscription.ClientCorrelator

			if newZoneId != oldZoneId {
				//process LEAVING events prior to entering ones
				if oldZoneId != "" {
					if userSubscriptionLeavingMap[subsId] != "" {
						zonal.ZoneId = oldZoneId
						zonal.CurrentAccessPointId = oldApId
						event := new(UserEventType)
						*event = LEAVING_EVENT
						zonal.UserEventType = event
						var inlineZonal InlineZonalPresenceNotification
						inlineZonal.ZonalPresenceNotification = &zonal
						sendZonalPresenceNotification(subscription.CallbackReference.NotifyURL, inlineZonal)
						log.Info("User Notification" + "(" + subsIdStr + "): " + "Leaving event in zone " + oldZoneId + " for user " + userId)
					}
				}
				if userSubscriptionEnteringMap[subsId] != "" && newZoneId != "" {
					zonal.ZoneId = newZoneId
					zonal.CurrentAccessPointId = newApId
					event := new(UserEventType)
					*event = ENTERING_EVENT
					zonal.UserEventType = event
					var inlineZonal InlineZonalPresenceNotification
					inlineZonal.ZonalPresenceNotification = &zonal
					sendZonalPresenceNotification(subscription.CallbackReference.NotifyURL, inlineZonal)
					log.Info("User Notification" + "(" + subsIdStr + "): " + "Entering event in zone " + newZoneId + " for user " + userId)
				}

			} else {
				if newApId != oldApId {
					if userSubscriptionTransferringMap[subsId] != "" {
						zonal.ZoneId = newZoneId
						zonal.CurrentAccessPointId = newApId
						zonal.PreviousAccessPointId = oldApId
						event := new(UserEventType)
						*event = TRANSFERRING_EVENT
						zonal.UserEventType = event
						var inlineZonal InlineZonalPresenceNotification
						inlineZonal.ZonalPresenceNotification = &zonal
						sendZonalPresenceNotification(subscription.CallbackReference.NotifyURL, inlineZonal)
						log.Info("User Notification" + "(" + subsIdStr + "): " + " Transferring event within zone " + newZoneId + " for user " + userId + " from Ap " + oldApId + " to " + newApId)
					}
				}
			}
		}
	}
}

func sendZonalPresenceNotification(notifyUrl string, notification InlineZonalPresenceNotification) {
	startTime := time.Now()
	jsonNotif, err := json.Marshal(notification)
	if err != nil {
		log.Error(err)
		return
	}

	resp, err := http.Post(notifyUrl, "application/json", bytes.NewBuffer(jsonNotif))
	duration := float64(time.Since(startTime).Microseconds()) / 1000.0
	_ = httpLog.LogTx(notifyUrl, "POST", string(jsonNotif), resp, startTime)
	if err != nil {
		log.Error(err)
		met.ObserveNotification(sandboxName, serviceName, notifZonalPresence, notifyUrl, nil, duration)
		return
	}
	met.ObserveNotification(sandboxName, serviceName, notifZonalPresence, notifyUrl, resp, duration)
	defer resp.Body.Close()
}

func sendStatusNotification(notifyUrl string, notification InlineZoneStatusNotification) {
	startTime := time.Now()
	jsonNotif, err := json.Marshal(notification)
	if err != nil {
		log.Error(err)
		return
	}

	resp, err := http.Post(notifyUrl, "application/json", bytes.NewBuffer(jsonNotif))
	duration := float64(time.Since(startTime).Microseconds()) / 1000.0
	_ = httpLog.LogTx(notifyUrl, "POST", string(jsonNotif), resp, startTime)
	if err != nil {
		log.Error(err)
		met.ObserveNotification(sandboxName, serviceName, notifZoneStatus, notifyUrl, nil, duration)
		return
	}
	met.ObserveNotification(sandboxName, serviceName, notifZoneStatus, notifyUrl, resp, duration)
	defer resp.Body.Close()
}

func sendSubscriptionNotification(notifyUrl string, notification InlineSubscriptionNotification) {
	startTime := time.Now()
	jsonNotif, err := json.Marshal(notification)
	if err != nil {
		log.Error(err)
		return
	}

	resp, err := http.Post(notifyUrl, "application/json", bytes.NewBuffer(jsonNotif))
	duration := float64(time.Since(startTime).Microseconds()) / 1000.0
	_ = httpLog.LogTx(notifyUrl, "POST", string(jsonNotif), resp, startTime)
	if err != nil {
		log.Error(err)
		met.ObserveNotification(sandboxName, serviceName, notifSubscription, notifyUrl, nil, duration)
		return
	}
	met.ObserveNotification(sandboxName, serviceName, notifSubscription, notifyUrl, resp, duration)
	defer resp.Body.Close()
}

func checkNotificationRegisteredZones(oldZoneId string, newZoneId string, oldApId string, newApId string, userId string) {

	mutex.Lock()
	defer mutex.Unlock()

	//check all that applies
	for subsId, value := range zonalSubscriptionMap {

		if value == newZoneId {

			if newZoneId != oldZoneId {

				if zonalSubscriptionEnteringMap[subsId] != "" {
					subsIdStr := strconv.Itoa(subsId)

					jsonInfo, _ := rc.JSONGetEntry(baseKey+typeZonalSubscription+":"+subsIdStr, ".")
					if jsonInfo != "" {
						subscription := convertJsonToZonalSubscription(jsonInfo)

						var zonal ZonalPresenceNotification
						zonal.ZoneId = newZoneId
						zonal.CurrentAccessPointId = newApId
						zonal.Address = userId
						event := new(UserEventType)
						*event = ENTERING_EVENT
						zonal.UserEventType = event
						seconds := time.Now().Unix()
						var timestamp TimeStamp
						timestamp.Seconds = int32(seconds)
						zonal.Timestamp = &timestamp
						zonal.CallbackData = subscription.ClientCorrelator
						var inlineZonal InlineZonalPresenceNotification
						inlineZonal.ZonalPresenceNotification = &zonal
						sendZonalPresenceNotification(subscription.CallbackReference.NotifyURL, inlineZonal)
						log.Info("Zonal Notify Entering event in zone " + newZoneId + " for user " + userId)
					}
				}
			} else {
				if newApId != oldApId {
					if zonalSubscriptionTransferringMap[subsId] != "" {
						subsIdStr := strconv.Itoa(subsId)

						jsonInfo, _ := rc.JSONGetEntry(baseKey+typeZonalSubscription+":"+subsIdStr, ".")
						if jsonInfo != "" {
							subscription := convertJsonToZonalSubscription(jsonInfo)

							var zonal ZonalPresenceNotification
							zonal.ZoneId = newZoneId
							zonal.CurrentAccessPointId = newApId
							zonal.PreviousAccessPointId = oldApId
							zonal.Address = userId
							event := new(UserEventType)
							*event = TRANSFERRING_EVENT
							zonal.UserEventType = event
							seconds := time.Now().Unix()
							var timestamp TimeStamp
							timestamp.Seconds = int32(seconds)
							zonal.Timestamp = &timestamp
							zonal.CallbackData = subscription.ClientCorrelator
							var inlineZonal InlineZonalPresenceNotification
							inlineZonal.ZonalPresenceNotification = &zonal
							sendZonalPresenceNotification(subscription.CallbackReference.NotifyURL, inlineZonal)
							log.Info("Zonal Notify Transferring event in zone " + newZoneId + " for user " + userId + " from Ap " + oldApId + " to " + newApId)
						}
					}
				}
			}
		} else {
			if value == oldZoneId {
				if zonalSubscriptionLeavingMap[subsId] != "" {
					subsIdStr := strconv.Itoa(subsId)

					jsonInfo, _ := rc.JSONGetEntry(baseKey+typeZonalSubscription+":"+subsIdStr, ".")
					if jsonInfo != "" {

						subscription := convertJsonToZonalSubscription(jsonInfo)

						var zonal ZonalPresenceNotification
						zonal.ZoneId = oldZoneId
						zonal.CurrentAccessPointId = oldApId
						zonal.Address = userId
						event := new(UserEventType)
						*event = LEAVING_EVENT
						zonal.UserEventType = event
						seconds := time.Now().Unix()
						var timestamp TimeStamp
						timestamp.Seconds = int32(seconds)
						zonal.Timestamp = &timestamp
						zonal.CallbackData = subscription.ClientCorrelator
						var inlineZonal InlineZonalPresenceNotification
						inlineZonal.ZonalPresenceNotification = &zonal
						sendZonalPresenceNotification(subscription.CallbackReference.NotifyURL, inlineZonal)
						log.Info("Zonal Notify Leaving event in zone " + oldZoneId + " for user " + userId)
					}
				}
			}
		}
	}
}

func usersGet(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json; charset=UTF-8")
	var userData UeUserData

	// Retrieve query parameters
	u, _ := url.Parse(r.URL.String())
	log.Info("url: ", u.RequestURI())
	q := u.Query()
	userData.queryZoneId = q["zoneId"]
	userData.queryApId = q["accessPointId"]
	userData.queryAddress = q["address"]

	validQueryParams := []string{"zoneId", "accessPointId", "address"}

	//look for all query parameters to reject if any invalid ones
	found := false
	for queryParam := range q {
		found = false
		for _, validQueryParam := range validQueryParams {
			if queryParam == validQueryParam {
				found = true
				break
			}
		}
		if !found {
			log.Error("Query param not valid: ", queryParam)
			w.WriteHeader(http.StatusBadRequest)
			return
		}
	}

	// Get user list from DB
	var response InlineUserList
	var userList UserList
	userList.ResourceURL = hostUrl.String() + basePath + "queries/users"
	response.UserList = &userList
	userData.userList = &userList

	keyName := baseKey + typeUser + ":*"
	err := rc.ForEachJSONEntry(keyName, populateUserList, &userData)
	if err != nil {
		log.Error(err.Error())
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	// Send response
	jsonResponse, err := json.Marshal(response)
	if err != nil {
		log.Error(err.Error())
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusOK)
	fmt.Fprintf(w, string(jsonResponse))
}

func populateUserList(key string, jsonInfo string, userData interface{}) error {
	// Get query params & userlist from user data
	data := userData.(*UeUserData)
	if data == nil || data.userList == nil {
		return errors.New("userList not found in userData")