omnivore/apple/OmnivoreKit/Sources/App/Services.swift

import BackgroundTasks
import Foundation
import Models
import OSLog
import Services
import Utils

public final class Services {
  static let fetchTaskID = "app.omnivore.fetchLinkedItems"
  static let secondsToWaitBeforeNextBackgroundRefresh: TimeInterval = isDebug ? 0 : 3600 // 1 hour
  static let logger = Logger(subsystem: "app.omnivore", category: "services-class")

  public let authenticator: Authenticator
  public let dataService: DataService

  public init(appEnvironment: AppEnvironment = PublicValet.storedAppEnvironment ?? .initialAppEnvironment) {
    let networker = Networker(appEnvironment: appEnvironment)
    self.authenticator = Authenticator(networker: networker)
    self.dataService = DataService(appEnvironment: appEnvironment, networker: networker)
  }
}

#if os(iOS)
  // Background fetching functions
  extension Services {
    public static func registerBackgroundFetch() {
      BGTaskScheduler.shared.register(forTaskWithIdentifier: fetchTaskID, using: nil) { task in
        if let task = task as? BGAppRefreshTask {
          EventTracker.trackForDebugging("executing app.omnivore.fetchLinkedItems bg task")
          logger.debug("in background task register closure")
          performBackgroundFetch(task: task)
        }
      }
    }

    static func scheduleBackgroundFetch() {
      BGTaskScheduler.shared.cancelAllTaskRequests()
      let taskRequest = BGAppRefreshTaskRequest(identifier: fetchTaskID)
      taskRequest.earliestBeginDate = Date(timeIntervalSinceNow: secondsToWaitBeforeNextBackgroundRefresh)

      do {
        try BGTaskScheduler.shared.submit(taskRequest)
        logger.debug("\(fetchTaskID) task scheduled")
      } catch {
        logger.debug("task scheduling failed: \(fetchTaskID)")
      }
    }

    static func performBackgroundFetch(task: BGAppRefreshTask) {
      Services.logger.debug("starting background fetch")
      scheduleBackgroundFetch()
      let services = Services()

      task.expirationHandler = {
        EventTracker.trackForDebugging("background fetch expiration handler called")
        logger.debug("handling background fetch expiration")
      }

      guard services.authenticator.hasValidAuthToken else {
        EventTracker.trackForDebugging("background fetch failed: user does not have a valid auth token")
        Services.logger.debug("background fetch failed: user does not habe a valid auth token")
        task.setTaskCompleted(success: false)
        return
      }

      Task {
        do {
          try await services.dataService.fetchLinkedItemsBackgroundTask()
          logger.debug("fetch complete")
          EventTracker.trackForDebugging("background fetch task completed successfully")
          task.setTaskCompleted(success: true)
        } catch {
          logger.debug("fetch failed")
          EventTracker.trackForDebugging("background fetch task failed")
          task.setTaskCompleted(success: false)
        }
      }
    }
  }
#endif
// e -l objc -- (void)[[BGTaskScheduler sharedScheduler] _simulateLaunchForTaskWithIdentifier:@"app.omnivore.fetchLinkedItems"]