import Flutter
import UIKit

@main
@objc class AppDelegate: FlutterAppDelegate {

  private var secureField: UITextField?
  private var secureContainer: UIView?

  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    let controller = window?.rootViewController as! FlutterViewController
    let channel = FlutterMethodChannel(name: "ios_secure_screen", binaryMessenger: controller.binaryMessenger)

    channel.setMethodCallHandler { [weak self] call, result in
      guard let self = self else { return }
      switch call.method {
      case "enable":
        self.enableSecureMode()
        result(nil)
      case "disable":
        self.disableSecureMode()
        result(nil)
      default:
        result(FlutterMethodNotImplemented)
      }
    }

    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }

  private func enableSecureMode() {
    guard let window = self.window else { return }
    guard let flutterVC = window.rootViewController else { return }
    let flutterView = flutterVC.view!

    if secureContainer != nil { return }

    let field = UITextField(frame: window.bounds)
    field.isSecureTextEntry = true

    // IMPORTANTE: precisa ficar interativo, senão mata os toques do FlutterView
    field.isUserInteractionEnabled = true
    field.isEnabled = true
    field.textColor = .clear
    field.tintColor = .clear
    field.backgroundColor = .clear
    field.borderStyle = .none
    field.autocorrectionType = .no
    field.spellCheckingType = .no

    guard let container = field.subviews.first else { return }
    container.frame = window.bounds
    container.isUserInteractionEnabled = true

    flutterView.removeFromSuperview()
    container.addSubview(flutterView)
    flutterView.frame = container.bounds
    flutterView.autoresizingMask = [.flexibleWidth, .flexibleHeight]

    window.addSubview(field)
    field.frame = window.bounds
    field.autoresizingMask = [.flexibleWidth, .flexibleHeight]

    self.secureField = field
    self.secureContainer = container
  }

  private func disableSecureMode() {
    guard let window = self.window else { return }
    guard let flutterVC = window.rootViewController else { return }
    let flutterView = flutterVC.view!

    // Se não está habilitado, sai
    guard let field = secureField else { return }

    // Remove flutter do container e volta pra window
    flutterView.removeFromSuperview()
    window.insertSubview(flutterView, belowSubview: field)
    flutterView.frame = window.bounds
    flutterView.autoresizingMask = [.flexibleWidth, .flexibleHeight]

    // Remove o campo seguro
    field.removeFromSuperview()

    self.secureField = nil
    self.secureContainer = nil
  }

}