loc-serv.go

/*
 * Copyright (c) 2019
 * InterDigital Communications, Inc.
 * All rights reserved.
 *
 * The information provided herein is the proprietary and confidential
 * information of InterDigital Communications, Inc.
 */
package server

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

	log "github.com/InterDigitalInc/AdvantEDGE/go-apps/meep-loc-serv/log"
	db "github.com/InterDigitalInc/AdvantEDGE/go-apps/meep-loc-serv/redis"
	sbi "github.com/InterDigitalInc/AdvantEDGE/go-apps/meep-loc-serv/sbi"
	clientNotifOMA "github.com/InterDigitalInc/AdvantEDGE/go-packages/meep-loc-serv-notification-client"

	"github.com/KromDaniel/rejonson"
	"github.com/go-redis/redis"
	"github.com/gorilla/mux"
)

const basepathURL = "http://meep-loc-serv/etsi-013/location/v1/"
const moduleLocServ string = "loc-serv"

const typeZone = "zone"
const typeAccessPoint = "accessPoint"
const typeUser = "user"
const typeZonalSubscription = "zonalsubs"
const typeUserSubscription = "usersubs"
const typeZoneStatusSubscription = "zonestatus"

const locServChannel string = moduleLocServ

var nextZonalSubscriptionIdAvailable int
var nextUserSubscriptionIdAvailable int
var nextZoneStatusSubscriptionIdAvailable 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{}

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

var pubsub *redis.PubSub
var LOC_SERV_DB = 5
var dbClient *rejonson.Client

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

	// Connect to Redis DB
	dbClient, err = db.RedisDBConnect(LOC_SERV_DB)
	if err != nil {
		log.Error("Failed connection to Active DB for server. Error: ", err)
		return err
	}

	log.Info("Connected to Active location service DB")

	// Subscribe to Pub-Sub events for MEEP Controller
	// NOTE: Current implementation is RedisDB Pub-Sub
	pubsub, err = db.Subscribe(dbClient, locServChannel)
	if err != nil {
		log.Error("Failed to subscribe to Pub/Sub events. Error: ", err)
		return err
	}

	userTrackingReInit()
	zonalTrafficReInit()
	zoneStatusReInit()

	_ = sbi.Init(updateUserInfo, updateZoneInfo, updateAccessPointInfo)
	return nil
}

// Run - MEEP Location Service execution
func Run() {

	// Listen for subscribed events. Provide event handler method.
	_ = db.Listen(pubsub, eventHandler)
}

func eventHandler(channel string, payload string) {
	// Handle Message according to Rx Channel
	switch channel {

	// MEEP Ctrl Engine active scenario update Channel
	case locServChannel:
		log.Debug("Event received on location service channel in server : ", payload)
		go checkNotificationRegistrations(payload)

	default:
		log.Warn("Unsupported channel")
	}
}

func createClient(notifyPath string) (*clientNotifOMA.APIClient, error) {
	// Create & store client for App REST API
	subsAppClientCfg := clientNotifOMA.NewConfiguration()
	subsAppClientCfg.BasePath = notifyPath
	subsAppClient := clientNotifOMA.NewAPIClient(subsAppClientCfg)
	if subsAppClient == nil {
		log.Error("Failed to create Subscription App REST API client: ", subsAppClientCfg.BasePath)
		err := errors.New("Failed to create Subscription App REST API client")
		return nil, err
	}
	return subsAppClient, nil
}

func deregisterZoneStatus(subsIdStr string) {
	subsId, _ := strconv.Atoi(subsIdStr)
	zonalSubscriptionMap[subsId] = ""
}

func registerZoneStatus(zoneId string, nbOfUsersZoneThreshold uint32, nbOfUsersAPThreshold uint32, opStatus []OperationStatus, subsIdStr string) {

	subsId, _ := strconv.Atoi(subsIdStr)

	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 = (int)(nbOfUsersZoneThreshold)
	zoneStatus.NbUsersInAPThreshold = (int)(nbOfUsersAPThreshold)
	zoneStatus.ZoneId = zoneId

	zoneStatusSubscriptionMap[subsId] = &zoneStatus
}

func deregisterZonal(subsIdStr string) {
	subsId, _ := strconv.Atoi(subsIdStr)
	zonalSubscriptionMap[subsId] = ""
	zonalSubscriptionEnteringMap[subsId] = ""
	zonalSubscriptionLeavingMap[subsId] = ""
	zonalSubscriptionTransferringMap[subsId] = ""
}

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

	subsId, _ := strconv.Atoi(subsIdStr)

	if event != nil {
		for i := 0; i < len(event); i++ {
			switch event[i] {
			case ENTERING:
				zonalSubscriptionEnteringMap[subsId] = zoneId
			case LEAVING:
				zonalSubscriptionLeavingMap[subsId] = zoneId
			case TRANSFERRING:
				zonalSubscriptionTransferringMap[subsId] = zoneId
			default:
			}
		}
	} else {
		zonalSubscriptionEnteringMap[subsId] = zoneId
		zonalSubscriptionLeavingMap[subsId] = zoneId
		zonalSubscriptionTransferringMap[subsId] = zoneId
	}
	zonalSubscriptionMap[subsId] = zoneId
}

func deregisterUser(subsIdStr string) {
	subsId, _ := strconv.Atoi(subsIdStr)
	userSubscriptionMap[subsId] = ""
	userSubscriptionEnteringMap[subsId] = ""