gistfile1.txt

import UIKit
import CoreLocation

class LocationProvider: NSObject, CLLocationManagerDelegate {
  static let shared = LocationProvider()
  var city: String?
  var currentLocation: CLLocation?
  var lastRealOneLocation: CLLocation?
  private var locationList: [CLLocation] = []
  private let locationManager = CLLocationManager()
  var subscribe: ((CLLocation) -> Void)?
  private(set) var distance: Measurement<UnitLength> = .init(value: 0, unit: .meters)
  
  func requestPermissions() {
    locationManager.allowsBackgroundLocationUpdates = true
    locationManager.showsBackgroundLocationIndicator = true
    locationManager.delegate = self
    locationManager.activityType = .fitness
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestAlwaysAuthorization()
    locationManager.requestWhenInUseAuthorization()
    locationManager.requestLocation()
  }
  
  func resetDistance() {
    distance = .init(value: 0, unit: .meters)
  }
  
  func startFetchingLocation() {
    locationManager.startUpdatingLocation()
  }
  
  func forceRequestSubcribe() {
    guard let myLocation = currentLocation else {
      return
    }
    
     subscribe?(myLocation)
  }
  
  func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
    
  }
  var lastLocationDate: Date?
  
  func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    guard let location = locations.first else {
      return
    }
    self.lastRealOneLocation = location
    let speed = location.speed * 3.6 // km/h
    let time = Date().timeIntervalSince(lastLocationDate ?? Date()) / 60 / 60 // h
    let maxDistance = time * speed // km
    
    let newLocation = locations.sorted {
      $0.horizontalAccuracy < $1.horizontalAccuracy
    }.first!
    if let lastLocation = locationList.last {
      let delta = newLocation.distance(from: lastLocation)
      let newDistance = Measurement(value: delta, unit: UnitLength.meters)
//      UIApplication.shared.keyWindow?.makeToast("\(maxDistance), \(newDistance.value / 1000)")
      let coeff: Double = 0.75
      if (newDistance.value / 1000) * coeff > maxDistance {
        // new Distance should not be over than maxDistance
        return
      }
      distance = distance + newDistance
      
    }
    
    locationList.append(newLocation)
    
    subscribe?(location)
    self.currentLocation = location
    self.lastLocationDate = Date()
    let geocoder = CLGeocoder()
    geocoder.reverseGeocodeLocation(location) { (placemarks, error) in
      if let placemark = placemarks?.first {
        self.city = placemark.locality
      }
    }
  }
}