LocationDataManager.swift

Purpose 

The LocationDataManager.swift class handles location tracking using CoreLocation and coordinates with the FileHandler to attach location metadata to sensor data collected by the HealthyWear app.

Key Responsibilities 

Manages continuous location updates with CLLocationManager.
Provides the last known location to sensor data when saving.
Verifies location permission status and responds to system callbacks.
Designed as a singleton to allow shared access across modules.

Singleton Setup 

static let shared = LocationDataManager()

Provides global access to a single instance across the iOS app.

Properties 

private var locationManager = CLLocationManager()
private var lastKnownLocation: CLLocation?

locationManager: CoreLocation’s central controller.
lastKnownLocation: Stores the most recent location data.

Initialization 

override init() {
    super.init()
    locationManager.delegate = self
    locationManager.requestWhenInUseAuthorization()
}

Requests permission and sets up the delegate on initialization.

Start Location Updates 

private func startLocationUpdates()

Uses DispatchQueue.main.async to ensure updates run on the main thread.
Sets desiredAccuracy to kCLLocationAccuracyHundredMeters for balance of precision and battery.
TODO: Improve by throttling updates (e.g., every 50 seconds).

Saving Sensor Data with Location 

func fetchLocationAndSaveData(dataType: String, dataBuffer: [String], completion: @escaping (Bool) -> Void)

Ensures a valid location exists.
Passes location coordinates and buffer to FileHandler.shared.saveDataToFile.

CLLocationManagerDelegate Methods 

`didChangeAuthorization`

Handles permission changes:

Starts updates if authorized.
Logs if denied or restricted.

`didUpdateLocations`

Updates the lastKnownLocation with the most recent GPS result.

`didFailWithError`

Handles failure and prints debugging message.

Utility Method 

func checkLocationServicesAndNotify()

Verifies if location services are enabled.
If not, prints instructions to enable them in device settings.

Integration 

Used whenever sensor data must be saved with geolocation context. This includes:

Smart sock recordings
Smart band sensor streams
Motion sensors