class HeartRateRecevier {
    var delegate: HeartRateReceiverDelegate?
    var currentHeartRate: Int? {
        didSet {
            if let currentHeartRate = currentHeartRate {
                delegate?.heartRateUpdate(to: currentHeartRate)
                //print("The most recent heart rate received was (currentHeartRate)")
            } else {
                print("Looks like we can't pick up a heart rate")
            }
        }
    }

    func startHeartRateMonitoringExample(){
        for _ in 1...10 {
            let randomHeartRate = 60 + Int(arc4random_uniform(UInt32(15)))
            currentHeartRate = randomHeartRate
            Thread.sleep(forTimeInterval: 2)
        }
    }
}

protocol HeartRateReceiverDelegate {
    func heartRateUpdate(to bpm: Int)
}

class HeartRateViewController: UIViewController, HeartRateReceiverDelegate {
    @IBOutlet weak var heartRateLabel: UILabel!
    var heartRateReceiver = HeartRateRecevier()

    override func viewDidLoad() {
        super.viewDidLoad()
        heartRateReceiver.delegate = self
    }
    // Here we have the mandatory function of the protocol
    func heartRateUpdate(to bpm: Int) {
        heartRateLabel.text = "The heart rate is: (bpm)"
    }
    @IBAction func beginTestButton() {
        heartRateReceiver.startHeartRateMonitoringExample()
    }
}