res_levis_backend/internal/pkg/location/assign.go

package location

import (
	"log/slog"
	"time"

	"github.com/AFASystems/presence/internal/pkg/common/appcontext"
	"github.com/AFASystems/presence/internal/pkg/common/utils"
)

// AssignBeaconToList updates app state with a new beacon advertisement: appends a metric
// to the beacon's sliding window and updates last seen.
func AssignBeaconToList(adv appcontext.BeaconAdvertisement, appState *appcontext.AppState) {
	id := adv.ID
	now := time.Now().Unix()
	settings := appState.GetSettingsValue()

	if settings.RSSIEnforceThreshold && int64(adv.RSSI) < settings.RSSIMinThreshold {
		slog.Debug("settings RSSI threshold filter", "id", id)
		return
	}

	beacon, ok := appState.GetBeacon(id)
	if !ok {
		beacon = appcontext.Beacon{ID: id}
	}

	beacon.IncomingJSON = adv
	beacon.LastSeen = now

	if beacon.BeaconMetrics == nil {
		beacon.BeaconMetrics = make([]appcontext.BeaconMetric, 0, settings.BeaconMetricSize)
	}

	metric := appcontext.BeaconMetric{
		Distance:  utils.CalculateDistance(adv),
		Timestamp: now,
		RSSI:      int64(adv.RSSI),
		Location:  adv.Hostname,
	}

	if len(beacon.BeaconMetrics) >= settings.BeaconMetricSize {
		copy(beacon.BeaconMetrics, beacon.BeaconMetrics[1:])
		beacon.BeaconMetrics[settings.BeaconMetricSize-1] = metric
	} else {
		beacon.BeaconMetrics = append(beacon.BeaconMetrics, metric)
	}

	appState.UpdateBeacon(id, beacon)
}