import AppKit
import Network

/// Held by the composition, independently of workspace windows.
@MainActor
final class ConnectivityLifecycle: NSObject, NSApplicationDelegate {
  let module: ServerConnectivity
  private let monitor = NWPathMonitor()
  private var receivedInitialPath = false
  private var terminating = false

  init(module: ServerConnectivity) {
    self.module = module
    super.init()
    monitor.pathUpdateHandler = { [weak self] _ in
      Task { @MainActor in
        guard let self else { return }
        if self.receivedInitialPath { self.module.networkChanged() }
        self.receivedInitialPath = true
      }
    }
    monitor.start(queue: DispatchQueue(label: "connectivity.network"))
  }

  func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
    guard !terminating else { return .terminateLater }
    terminating = true
    monitor.cancel()
    Task {
      await module.shutdown()
      sender.reply(toApplicationShouldTerminate: true)
    }
    return .terminateLater
  }
}

@MainActor
final class ConnectivityApplicationDelegate: NSObject, NSApplicationDelegate {
  var lifecycle: ConnectivityLifecycle?
  var catalogWorkflow: CatalogWorkflow?

  func applicationDidFinishLaunching(_ notification: Notification) {
    catalogWorkflow?.startSubscriptionAutomaticUpdates()
    NSWorkspace.shared.notificationCenter.addObserver(
      self, selector: #selector(didWake), name: NSWorkspace.didWakeNotification, object: nil)
  }

  @objc private func didWake(_ notification: Notification) {
    catalogWorkflow?.subscriptionAutomaticUpdatesDidWake()
  }

  func applicationWillTerminate(_ notification: Notification) {
    catalogWorkflow?.stopSubscriptionAutomaticUpdates()
    NSWorkspace.shared.notificationCenter.removeObserver(self)
  }

  func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
    catalogWorkflow?.stopSubscriptionAutomaticUpdates()
    return lifecycle?.applicationShouldTerminate(sender) ?? .terminateNow
  }
}