import Expo
import React
import ReactAppDependencyProvider
import BackgroundTasks

@UIApplicationMain
public class AppDelegate: ExpoAppDelegate {
  var window: UIWindow?

  var reactNativeDelegate: ExpoReactNativeFactoryDelegate?
  var reactNativeFactory: RCTReactNativeFactory?

  public override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
  ) -> Bool {
    // 在应用启动完成前注册后台任务
    if #available(iOS 13.0, *) {
      registerBackgroundTasks()
    }
    
    let delegate = ReactNativeDelegate()
    let factory = ExpoReactNativeFactory(delegate: delegate)
    delegate.dependencyProvider = RCTAppDependencyProvider()

    reactNativeDelegate = delegate
    reactNativeFactory = factory
    bindReactNativeFactory(factory)

#if os(iOS) || os(tvOS)
    window = UIWindow(frame: UIScreen.main.bounds)
    factory.startReactNative(
      withModuleName: "main",
      in: window,
      launchOptions: launchOptions)
#endif

    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
  
  // MARK: - Background Task Registration
  
  @available(iOS 13.0, *)
  private func registerBackgroundTasks() {
    let identifier = "com.anonymous.digitalpilates.task"
    
    // 注册后台任务处理器
    // 必须在应用启动完成前注册，否则会崩溃
    BGTaskScheduler.shared.register(
      forTaskWithIdentifier: identifier,
      using: nil
    ) { [weak self] task in
      // 尝试通知 BackgroundTaskBridge 处理任务
      // 如果 bridge 不可用，标记任务完成
      self?.handleBackgroundTask(task, identifier: identifier)
    }
    
    NSLog("[AppDelegate] 后台任务已在应用启动时注册: \(identifier)")
  }
  
  @available(iOS 13.0, *)
  private func handleBackgroundTask(_ task: BGTask, identifier: String) {
    // 尝试获取 BackgroundTaskBridge 实例来处理任务
    // 如果 React Native bridge 还未初始化，则直接完成任务
    guard let bridge = reactNativeFactory?.bridge,
          bridge.isValid else {
      NSLog("[AppDelegate] React Native bridge 未就绪，直接完成后台任务")
      task.setTaskCompleted(success: false)
      return
    }
    
    // 通过 bridge 查找 BackgroundTaskBridge 模块
    DispatchQueue.main.async {
      if let module = bridge.module(for: BackgroundTaskBridge.self) as? BackgroundTaskBridge {
        // 通知 BackgroundTaskBridge 处理任务
        NotificationCenter.default.post(
          name: NSNotification.Name("BackgroundTaskBridge.handleTask"),
          object: nil,
          userInfo: ["task": task, "identifier": identifier]
        )
      } else {
        NSLog("[AppDelegate] BackgroundTaskBridge 模块未找到，完成后台任务")
        task.setTaskCompleted(success: false)
      }
    }
  }

  // Linking API
  public override func application(
    _ app: UIApplication,
    open url: URL,
    options: [UIApplication.OpenURLOptionsKey: Any] = [:]
  ) -> Bool {
    return super.application(app, open: url, options: options) || RCTLinkingManager.application(app, open: url, options: options)
  }

  // Universal Links
  public override func application(
    _ application: UIApplication,
    continue userActivity: NSUserActivity,
    restorationHandler: @escaping ([UIUserActivityRestoring]?) -> Void
  ) -> Bool {
    let result = RCTLinkingManager.application(application, continue: userActivity, restorationHandler: restorationHandler)
    return super.application(application, continue: userActivity, restorationHandler: restorationHandler) || result
  }
}

class ReactNativeDelegate: ExpoReactNativeFactoryDelegate {
  // Extension point for config-plugins

  override func sourceURL(for bridge: RCTBridge) -> URL? {
    // needed to return the correct URL for expo-dev-client.
    bridge.bundleURL ?? bundleURL()
  }

  override func bundleURL() -> URL? {
#if DEBUG
    return RCTBundleURLProvider.sharedSettings().jsBundleURL(forBundleRoot: ".expo/.virtual-metro-entry")
#else
    return Bundle.main.url(forResource: "main", withExtension: "jsbundle")
#endif
  }
}