import Flutter
import UIKit
import YandexLoginSDK

/// iOS 27 requires a UIScene lifecycle. Flutter 3.38 does not yet have
/// `FlutterImplicitEngineDelegate`, so channels and URL handling are wired
/// here after the scene creates the Flutter view.
class SceneDelegate: FlutterSceneDelegate {
  override func scene(
    _ scene: UIScene,
    willConnectTo session: UISceneSession,
    options connectionOptions: UIScene.ConnectionOptions
  ) {
    super.scene(scene, willConnectTo: session, options: connectionOptions)
    registerCallChannels()
    handleConnectionOptions(connectionOptions)
  }

  override func sceneDidBecomeActive(_ scene: UIScene) {
    super.sceneDidBecomeActive(scene)
    registerCallChannels()
  }

  override func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
    var handledCustomURL = false
    if let appDelegate = UIApplication.shared.delegate as? AppDelegate {
      for context in URLContexts {
        if appDelegate.handleOpenURL(
          context.url,
          sourceApplication: context.options.sourceApplication
        ) {
          handledCustomURL = true
        }
      }
    }
    if !handledCustomURL {
      super.scene(scene, openURLContexts: URLContexts)
    }
  }

  override func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {
    if YXLSdk.shared.processUserActivity(userActivity) {
      return
    }
    super.scene(scene, continue: userActivity)
  }

  private func registerCallChannels() {
    guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
      return
    }
    appDelegate.registerCallChannels(from: flutterViewController)
  }

  private var flutterViewController: FlutterViewController? {
    if let controller = window?.rootViewController as? FlutterViewController {
      return controller
    }
    for scene in UIApplication.shared.connectedScenes {
      guard let windowScene = scene as? UIWindowScene else { continue }
      for sceneWindow in windowScene.windows {
        if let controller = sceneWindow.rootViewController as? FlutterViewController {
          return controller
        }
      }
    }
    return nil
  }

  private func handleConnectionOptions(_ options: UIScene.ConnectionOptions) {
    guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
      return
    }
    for context in options.urlContexts {
      _ = appDelegate.handleOpenURL(
        context.url,
        sourceApplication: context.options.sourceApplication
      )
    }
    for activity in options.userActivities {
      if YXLSdk.shared.processUserActivity(activity) {
        continue
      }
    }
  }
}