import Foundation

final class AppState: ObservableObject {
  @Published var count: Int = 0
}

import SwiftUI

@main
struct DI_TestApp: App {
  var body: some Scene {
    let appDI = AppState()
    WindowGroup {
      RootView()
        .environmentObject(appDI)
    }
  }
}

RootView ├── TestView ── TestView2
         ├── ContentView

import SwiftUI

struct TestView: View {
  @EnvironmentObject
  var appState: AppState

  var body: some View {
    VStack {
      NavigationLink(
        destination: { TestView2() },
        label: {
          Text("Push")
        }
      )

      Button(
        action: {
          appState.count += 1
        },
        label: {
          Text("up")
        }
      )
    }
  }
}

struct TestView2: View {
  @EnvironmentObject
  var appState: AppState

  var body: some View {
    Text("\(appState.count)")
  }
}

private func rootViewChange() {
    let window = UIApplication
      .shared
      .connectedScenes
      .flatMap { ($0 as? UIWindowScene)?.windows ?? [] }
      .first { $0.isKeyWindow }

    window?.rootViewController = UIHostingController(rootView: ContentView())
    window?.makeKeyAndVisible()
  }

struct ContentView: View {
  @EnvironmentObject
  var appState: AppState

  var body: some View {
    VStack {
      Image(systemName: "globe")
        .imageScale(.large)
        .foregroundColor(.accentColor)

      Text("Hello, world!")

      Text("\(appState.count)")
    }
    .padding()
  }
}

final class DefaultSearchMediaUseCase: SearchMediaUseCase {
  private let mediaRepository: MediaRepository
  private let mediaDetailRepository: MediaDetailRepository

  init(
    mediaRepository: MediaRepository,
    mediaDetailRepository: MediaDetailRepository
  ) {
    self.mediaRepository = mediaRepository
    self.mediaDetailRepository = mediaDetailRepository
  }
...
}

final class ~~ViewModel {
	private let usecase: SearchMediaUsecase

	init(
		usecase: SearchMediaUsecase
	) {
		self.usecase = usecase
	}
}

import Foundation

final class AppDI: AppDIInterface {
  private let mediaUsecase: SearchMediaUseCase = DefaultSearchMediaUseCase(
    mediaRepository: MediaRepositoryImpl(),
    mediaDetailRepository: MediaDetailRepositoryImpl(RealmDataStorage.shared)
  )

  func mediaDetailViewModel(
    _ media: Media
  ) -> MediaDetailViewModel {
    return MediaDetailViewModel(
      media: media,
      usecase: mediaUsecase
    )
  }
}

import Foundation

final class AppDI: AppDIInterface {
  private lazy var mediaUsecase: SearchMediaUseCase = {
    let mediaRepository: MediaRepository = MediaRepositoryImpl()
    let mediaDetailRepository: MediaDetailRepository = MediaDetailRepositoryImpl(RealmDataStorage.shared)
    return DefaultSearchMediaUseCase(
      mediaRepository: mediaRepository,
      mediaDetailRepository: mediaDetailRepository
    )
  }()

  func mediaDetailViewModel(
    _ media: Media
  ) -> MediaDetailViewModel {
    return MediaDetailViewModel(
      media: media,
      usecase: mediaUsecase
    )
  }
}