import Flutter
import UIKit
import receive_sharing_intent

// FlutterSceneDelegate has a fallback that forwards URL events to plugins
// registered via addApplicationDelegate, but the fallback is best-effort and
// has not always fired in our setup. This subclass forwards URLs explicitly
// to receive_sharing_intent so cold-start and warm shares both reach Dart.
class SceneDelegate: FlutterSceneDelegate {
  override func scene(
    _ scene: UIScene,
    willConnectTo session: UISceneSession,
    options connectionOptions: UIScene.ConnectionOptions
  ) {
    super.scene(scene, willConnectTo: session, options: connectionOptions)
    var handledShare = false
    for context in connectionOptions.urlContexts where isShareUrl(context.url) {
      _ = ReceiveSharingIntentPlugin.instance.application(
        UIApplication.shared,
        didFinishLaunchingWithOptions: [UIApplication.LaunchOptionsKey.url: context.url]
      )
      handledShare = true
    }
    if handledShare { clearSharedPayload() }
  }

  override func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
    let shares = URLContexts.filter { isShareUrl($0.url) }
    for context in shares {
      _ = ReceiveSharingIntentPlugin.instance.application(
        UIApplication.shared,
        open: context.url,
        options: [:]
      )
    }
    if !shares.isEmpty { clearSharedPayload() }
    let others = URLContexts.subtracting(shares)
    if !others.isEmpty { super.scene(scene, openURLContexts: others) }
  }

  private func isShareUrl(_ url: URL) -> Bool {
    ReceiveSharingIntentPlugin.instance.hasMatchingSchemePrefix(url: url)
  }

  // The plugin keeps the payload in memory once read but never removes it
  // from the App Group defaults. The Share Extension opens the app twice per
  // share and a scene reconnect replays the URL, so every later delivery
  // would publish the finished share again.
  private func clearSharedPayload() {
    let groupId = Bundle.main.object(forInfoDictionaryKey: "AppGroupId") as? String
    let defaults = UserDefaults(
      suiteName: groupId ?? "group.\(Bundle.main.bundleIdentifier ?? "")")
    defaults?.removeObject(forKey: "ShareKey")
    defaults?.removeObject(forKey: "ShareMessageKey")
  }
}