View+presentWithUIKit.swift

import UIKit
import SwiftUI

fileprivate final class PresentedViewController: UIHostingController<AnyView> {
  var key: UUID?
  var willDisappear: (() -> Void)?

  override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    if isBeingDismissed && presentedViewController == nil {
      willDisappear?()
    }
  }
}

fileprivate struct PresentableView<Content: View>: UIViewControllerRepresentable {
  @Binding private var isPresented: Bool
  private let modalPresentationStyle: UIModalPresentationStyle
  private let content: () -> Content
  @State private var didPresent = false
  @State  private var key: UUID = .init()

  init(
    isPresented: Binding<Bool>,
    modalPresentationStyle: UIModalPresentationStyle,
    @ViewBuilder content: @escaping () -> Content
  ) {
    _isPresented = isPresented
    self.modalPresentationStyle = modalPresentationStyle
    self.content = content
  }

  func makeUIViewController(context: Context) -> UIViewController {
    let uiViewController = UIViewController()
    let contentView = uiViewController.view!
    contentView.backgroundColor = .clear
    contentView.isUserInteractionEnabled = false
    return uiViewController
  }
  
  func updateUIViewController(_ uiViewController: UIViewController, context: Context) {
    if isPresented {
      if 
        let hostingController = uiViewController.presentedViewController as? PresentedViewController
      {
        hostingController.rootView = AnyView(content())
        return
      }

      let hostingController = PresentedViewController(rootView: AnyView(content()))
      hostingController.key = key
      hostingController.willDisappear = {
        isPresented = false
      }
      hostingController.modalPresentationStyle = modalPresentationStyle
      uiViewController.present(hostingController, animated: true) {
        didPresent = true
      }
    } else {
      if 
        didPresent,
        let presentedViewController = uiViewController.presentedViewController as? PresentedViewController,
        presentedViewController.key == key
      {
        presentedViewController.dismiss(animated: true)
      }
    }
  }
}

extension View {
  func presentWithUIKit<Content: View>(
    isPresented: Binding<Bool>,
    modalPresentationStyle: UIModalPresentationStyle,
    @ViewBuilder content: @escaping () -> Content
  ) -> some View {
    return overlay {
      PresentableView(isPresented: isPresented, modalPresentationStyle: modalPresentationStyle, content: content)
        .frame(width: .zero, height: .zero)
    }
  }
}