//
//  HomeVC.swift
//  WOKA
//
//  Created by Bilal on 24/05/2024.
//

import UIKit

protocol ChildViewControllerDelegate: AnyObject {
    func didPressSwitchButton(from viewController: UIViewController)
}

class HomeVC: UIViewController ,ChildViewControllerDelegate{

    @IBOutlet weak var containerView: UIView!
    var currentChildViewController: UIViewController?

    override func viewDidLoad() {
        super.viewDidLoad()

        switch AuthFunc.shareInstance.selectedTheme {
        case .theme1:
            let sb = UIStoryboard(name: K.StoryBoard.theme, bundle: nil)
            if let firstVC = sb.instantiateViewController(withIdentifier: K.StoryBoardID.Theme.themeOneVC) as? ThemeOneVC {
                add(asChildViewController: firstVC)
                firstVC.delegate = self
            }
        case .theme2:
            let sb = UIStoryboard(name: K.StoryBoard.theme, bundle: nil)
            if let firstVC = sb.instantiateViewController(withIdentifier:  K.StoryBoardID.Theme.themeTwoVC) as? ThemeTwoVC {
                add(asChildViewController: firstVC)
                firstVC.delegate = self
            }
        }
    }

    func didPressSwitchButton(from viewController: UIViewController) {
        if viewController is ThemeOneVC {
            switchToViewController(withIdentifier: K.StoryBoardID.Theme.themeTwoVC)
        } else if viewController is ThemeTwoVC {
            switchToViewController(withIdentifier: K.StoryBoardID.Theme.themeOneVC)
        }
    }
    
    
    private func switchToViewController(withIdentifier identifier: String) {
        let sb = UIStoryboard(name:  K.StoryBoard.theme, bundle: nil)
        let newVC = sb.instantiateViewController(withIdentifier: identifier)
        if let newVC = newVC as? ThemeOneVC {
            newVC.delegate = self
        } else if let newVC = newVC as? ThemeTwoVC {
            newVC.delegate = self
        }
        
        print("Switching to view controller with identifier \(identifier)")
        DispatchQueue.main.async { [weak self] in
            guard let self else{return}
            self.replaceCurrentChildViewController(with: newVC)
        }
    }

    private func add(asChildViewController viewController: UIViewController) {
        print("Adding child view controller: \(viewController)")
        addChild(viewController)
        viewController.view.frame = containerView.bounds
        containerView.addSubview(viewController.view)
        viewController.didMove(toParent: self)
        currentChildViewController = viewController
    }

    private func remove(asChildViewController viewController: UIViewController, onCompletion : @escaping () -> Void) {
        print("Removing child view controller: \(viewController)")
        viewController.willMove(toParent: nil)
        viewController.view.removeFromSuperview()
        viewController.removeFromParent()
        onCompletion()
    }
    
    private func replaceCurrentChildViewController(with newViewController: UIViewController) {
        // Clear previous views
        containerView.subviews.forEach { $0.removeFromSuperview() }
        
        // Remove current child view controller if exists
        if let currentVC = currentChildViewController {
            remove(asChildViewController: currentVC) { [weak self] in
                guard let self else{return}
                // Add new child view controller
                add(asChildViewController: newViewController)
            }
        }
    }
}