//
//  UIApplication.swift
//  VDS
//
//  Created by Matt Bruce on 4/14/23.
//

import Foundation
import UIKit

extension UIApplication {
    
    /// Synchronously finds the top most viewcontroller in the app
    /// - Parameter controller: Optional UIViewController to start from. If nil, starts from the root view controller.
    /// - Returns: The found top most UIViewController
    public class func topViewController(controller: UIViewController? = nil) -> UIViewController? {
        // Ensure we're on the main thread
        guard Thread.isMainThread else {
            fatalError("topViewController must be called from the main thread")
        }

        var rootController = controller

        if rootController == nil {
            if let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene,
               let rootVC = windowScene.windows.first(where: { $0.isKeyWindow })?.rootViewController {
                rootController = rootVC
            }
        }

        // Proceed with the logic to find the top view controller
        if let nav = rootController as? UINavigationController {
            return topViewController(controller: nav.visibleViewController)
        } else if let tab = rootController as? UITabBarController, let selected = tab.selectedViewController {
            return topViewController(controller: selected)
        } else if let presented = rootController?.presentedViewController {
            return topViewController(controller: presented)
        }

        return rootController
    }
}