Schedule notifications at given times

Notification.swift

import UIKit

protocol NotificationScheduler {
  func scheduleNotification(with title: String)
}

class NotificationManager {
  let notificationScheduler: NotificationScheduler 
  
  init(notificationScheduler: NotificationScheduler) {
    self.notificationScheduler = notificationScheduler
  }
  
  private func getCurrentHour() -> Int? {
    let calendar = Calendar(identifier: .gregorian)
    let date = Date()
    let hour = calendar.component(Calendar.Component.hour, from: date)
    return hour
  }
  
  func scheduleMorningNotification() {
    guard 
      let hour = self.getCurrentHour,
      hour < 11
    else {
      return
    }
    let title = "Good Morning!"
    self.notificationScheduler.scheduleNotification(with: title)
  }
  
  func scheduleNoonNotification() {
    guard 
      let hour = self.getCurrentHour,
      hour > 11,
      hour < 14
    else {
      return
    }
    let title = "Enjoy your lunch!"
    self.notificationScheduler.scheduleNotification(with: title)
  }
  
  func scheduleDinnerNotification() {
    guard 
      let hour = self.getCurrentHour,
      hour > 19
    else {
      return
    }
    let title = "Enjoy your dinner!"
    self.notificationScheduler.scheduleNotification(with: title)
  }
}