Coordinator pattern for navigation flow

import UIKit

class AppCoordinator: Coordinator {
    var navigationController: UINavigationController
    var childCoordinators: [Coordinator] = []

    private let window: UIWindow

    init(window: UIWindow) {
        self.window = window
        self.navigationController = UINavigationController()
    }

    func start() {
        // Check if user is logged in
        if AuthManager.shared.isLoggedIn {
            showMainFlow()
        } else {
            showAuthFlow()
        }

        window.rootViewController = navigationController
        window.makeKeyAndVisible()
    }

    private func showAuthFlow() {
        let authCoordinator = AuthCoordinator(navigationController: navigationController)
        authCoordinator.delegate = self
        addChild(authCoordinator)
        authCoordinator.start()
    }

    private func showMainFlow() {
        let mainCoordinator = MainCoordinator(navigationController: navigationController)
        addChild(mainCoordinator)
        mainCoordinator.start()
    }
}

extension AppCoordinator: AuthCoordinatorDelegate {
    func authCoordinatorDidFinish(_ coordinator: AuthCoordinator) {
        removeChild(coordinator)
        showMainFlow()
    }
}

import UIKit

class PostsCoordinator: Coordinator {
    var navigationController: UINavigationController
    var childCoordinators: [Coordinator] = []

    init(navigationController: UINavigationController) {
        self.navigationController = navigationController
    }

    func start() {
        let viewModel = PostsViewModel()
        let viewController = PostsViewController(viewModel: viewModel)
        viewController.coordinator = self
        navigationController.pushViewController(viewController, animated: true)
    }

    func showPostDetail(postId: Int) {
        let viewModel = PostDetailViewModel(postId: postId)
        let viewController = PostDetailViewController(viewModel: viewModel)
        viewController.coordinator = self
        navigationController.pushViewController(viewController, animated: true)
    }

    func showCreatePost() {
        let createCoordinator = CreatePostCoordinator(
            navigationController: navigationController
        )
        createCoordinator.delegate = self
        addChild(createCoordinator)
        createCoordinator.start()
    }
}

protocol CreatePostCoordinatorDelegate: AnyObject {
    func createPostCoordinatorDidFinish(_ coordinator: CreatePostCoordinator)
}

extension PostsCoordinator: CreatePostCoordinatorDelegate {
    func createPostCoordinatorDidFinish(_ coordinator: CreatePostCoordinator) {
        removeChild(coordinator)
    }
}