UserNotificationsHandling

UserNotificationsHandling.swift

//
//  UserNotificationsHandling.swift
//
//  Copyright © 2023 Eren Kabakci. All rights reserved.
//

import UserNotifications
import AppKit

// Generic local notifications API for any consumer to use
protocol UserNotificationsHandling {
  func promptAuthorization()
  func getNotificationSettings(completion: @escaping (_ enabled: Bool) -> Void)
  func schedule(title: String,
                body: String,
                metaData: UserNotificationMetadata?,
                completion: @escaping (Result<Void, Error>) -> Void)
  func removeAllPendingNotificationRequests()
  func removeAllDeliveredNotifications()
}

extension UNUserNotificationCenter: UserNotificationsHandling {
  func getNotificationSettings(completion: @escaping (_ enabled: Bool) -> Void) {
    getNotificationSettings(completionHandler: { settings in
      completion(settings.authorizationStatus == .authorized ? true : false)
    })
  }

  func promptAuthorization() {
    requestAuthorization(options: [.alert, .badge, .sound]) { _,_  in }
  }

  func schedule(title: String,
                body: String,
                metaData: UserNotificationMetadata?,
                completion: @escaping (Result<Void, Error>) -> Void) {
    promptAuthorization()

    getNotificationSettings { [weak self] notificationSettings in
      let correctAlertStyle = notificationSettings.alertStyle == UNAlertStyle.alert || notificationSettings.alertStyle == UNAlertStyle.banner
      let notificationsEnabled = notificationSettings.authorizationStatus != UNAuthorizationStatus.denied

      guard correctAlertStyle, notificationsEnabled else {
        if metaData == nil {
          DispatchQueue.main.async {
            let userAlert = NSAlert()
            userAlert.messageText = title
            userAlert.informativeText = body
            userAlert.alertStyle = NSAlert.Style.informational
            userAlert.addButton(withTitle: "OK")
            userAlert.runModal()
          }
        }

        return
      }

      let content = UNMutableNotificationContent()
      content.title = title
      content.body = body

      if let metaData {
        content.threadIdentifier = metaData.threadIdentifier
        content.categoryIdentifier = metaData.categoryIdentifier
        content.sound = metaData.sound
        content.userInfo = metaData.userInfo
      }

      let request = UNNotificationRequest(
        identifier: metaData?.identifier ?? UUID().uuidString,
        content: content,
        trigger: metaData?.trigger
      )

      self?.add(request) { error in
        if let error = error {
          completion(.failure(error))
        } else {
          completion(.success(()))
        }
      }
    }
  }
}

struct UserNotificationMetadata {
  let identifier: String?
  let trigger: UNNotificationTrigger?
  let categoryIdentifier: String
  let sound: UNNotificationSound
  let userInfo: [String: String]
  let threadIdentifier: String
}