res_levis_backend/cmd/decoder/main.go

package main

import (
	"encoding/hex"
	"fmt"
	"math"
	"strconv"
	"time"

	"github.com/AFASystems/presence/internal/pkg/config"
	"github.com/AFASystems/presence/internal/pkg/kafkaclient"
	"github.com/AFASystems/presence/internal/pkg/model"
	"github.com/AFASystems/presence/internal/pkg/mqttclient"
)

func main() {
	// Load global context to init beacons and latest list
	appCtx := model.AppContext{
		Beacons: model.BeaconsList{
			Beacons: make(map[string]model.Beacon),
		},
		LatestList: model.LatestBeaconsList{
			LatestList: make(map[string]model.Beacon),
		},
		Settings: model.Settings{
			Settings: model.SettingsVal{
				Location_confidence:  4,
				Last_seen_threshold:  15,
				Beacon_metrics_size:  30,
				HA_send_interval:     5,
				HA_send_changes_only: false,
			},
		},
	}

	fmt.Println("init")

	cfg := config.Load()

	// Kafka reader for Raw MQTT beacons
	rawReader := kafkaclient.KafkaReader(cfg.KafkaURL, "rawbeacons", "gid-raw")
	defer rawReader.Close()

	// Kafka reader for API server updates
	// apiReader := kafkaclient.KafkaReader(cfg.KafkaURL, "apibeacons", "gid-api")
	// defer apiReader.Close()

	// // Kafka reader for latest list updates
	// latestReader := kafkaclient.KafkaReader(cfg.KafkaURL, "latestbeacons", "gid-latest")
	// defer latestReader.Close()

	// // Kafka reader for settings updates
	// settingsReader := kafkaclient.KafkaReader(cfg.KafkaURL, "settings", "gid-settings")
	// defer settingsReader.Close()

	// declare channel for collecting Kafka messages
	chRaw := make(chan model.Incoming_json, 2000)
	// chApi := make(chan model.ApiUpdate, 2000)
	// chLatest := make(chan model.Incoming_json, 2000)
	// chSettings := make(chan model.SettingsVal, 10)

	go kafkaclient.Consume(rawReader, chRaw)
	// go kafkaclient.Consume(apiReader, chApi)
	// go kafkaclient.Consume(latestReader, chLatest)
	// go kafkaclient.Consume(settingsReader, chSettings)

	for {
		select {
		case msg := <-chRaw:
			processIncoming(msg, &appCtx)
			// case msg := <-chApi:
			// 	switch msg.Method {
			// 	case "POST":
			// 		fmt.Println("Incoming POST")
			// 		appCtx.Beacons.Lock.Lock()
			// 		appCtx.Beacons.Beacons[msg.Beacon.Beacon_id] = msg.Beacon
			// 	case "DELETE":
			// 		fmt.Println("Incoming delete")
			// 		_, exists := appCtx.Beacons.Beacons[msg.ID]
			// 		if exists {
			// 			appCtx.Beacons.Lock.Lock()
			// 			delete(appCtx.Beacons.Beacons, msg.ID)
			// 		}
			// 	default:
			// 		fmt.Println("unknown method: ", msg.Method)
			// 	}
			// 	appCtx.Beacons.Lock.Unlock()
			// case msg := <-chLatest:
			// 	fmt.Println("latest msg: ", msg)
			// case msg := <-chSettings:
			// 	appCtx.Settings.Lock.Lock()
			// 	appCtx.Settings.Settings = msg
			// 	fmt.Println("settings channel: ", msg)
			// 	appCtx.Settings.Lock.Unlock()
		}
	}
}

func processIncoming(incoming model.Incoming_json, ctx *model.AppContext) {
	defer func() {
		if err := recover(); err != nil {
			fmt.Println("work failed:", err)
		}
	}()

	// Get ID
	id := mqttclient.GetBeaconID(incoming)
	fmt.Println(incoming.Data)

	beacons := &ctx.Beacons

	beacons.Lock.Lock()
	defer beacons.Lock.Unlock()

	incoming = mqttclient.IncomingBeaconFilter(incoming)

	beacon, exists := beacons.Beacons[id]
	if !exists {
		return
	}

	fmt.Printf("%+v\n", beacon)

	updateBeacon(&beacon, incoming)
	beacons.Beacons[id] = beacon
}

func processBeacon(hexStr string) {
	b, _ := hex.DecodeString(hexStr)

	if len(b) > 2 && b[0] == 0x02 && b[1] == 0x01 {
		b = b[2+int(b[0]):]
	}

	ads := ParseADFast(b)
	_ = ads
}

func ParseADFast(b []byte) [][2]int {
	var res [][2]int
	i := 0

	for i < len(b) {
		l := int(b[i])
		if l == 0 || i+1+l > len(b) {
			break
		}

		res = append(res, [2]int{i, i + 1 + l})

		i += 1 + l
	}

	return res
}

func getBeaconDistance(incoming model.Incoming_json) float64 {
	rssi := incoming.RSSI
	power := incoming.TX_power
	distance := 100.0

	ratio := float64(rssi) * (1.0 / float64(twos_comp(power)))
	if ratio < 1.0 {
		distance = math.Pow(ratio, 10)
	} else {
		distance = (0.89976)*math.Pow(ratio, 7.7095) + 0.111
	}
	return distance
}

func updateBeacon(beacon *model.Beacon, incoming model.Incoming_json) {
	now := time.Now().Unix()

	beacon.Incoming_JSON = incoming
	beacon.Last_seen = now
	beacon.Beacon_type = incoming.Beacon_type
	beacon.HB_ButtonCounter = incoming.HB_ButtonCounter
	beacon.HB_Battery = incoming.HB_Battery
	beacon.HB_RandomNonce = incoming.HB_RandomNonce
	beacon.HB_ButtonMode = incoming.HB_ButtonMode

	if beacon.Beacon_metrics == nil {
		beacon.Beacon_metrics = make([]model.BeaconMetric, 10)
	}

	metric := model.BeaconMetric{}
	metric.Distance = getBeaconDistance(incoming)
	metric.Timestamp = now
	metric.Rssi = int64(incoming.RSSI)
	metric.Location = incoming.Hostname
	beacon.Beacon_metrics = append(beacon.Beacon_metrics, metric)
}

func twos_comp(inp string) int64 {
	i, _ := strconv.ParseInt("0x"+inp, 0, 64)
	return i - 256
}