NavEventController.kt

// NavEventController.kt
interface NavEventController {
    val destinationState: SharedFlow<Destination>
    
    fun sendEvent(event: Event)
}

// NavEventControllerImpl.kt
internal class NavEventControllerImpl(
    private val appCoroutineScope: AppCoroutineScope,
) : NavEventController {

    private val navigationEventState: MutableSharedFlow<Event> = MutableSharedFlow()

    override val destinationState: SharedFlow<Destination> =
        navigationEventState
            .map { event ->
                event.nextDestination()
            }.shareIn(
                scope = CoroutineScope(appCoroutineScope.context),
                started = SharingStarted.WhileSubscribed(),
            )

    override fun sendEvent(event: Event) {
        appCoroutineScope.launch {
            navigationEventState.emit(event)
        }
    }
}