MoviesViewModel.kt

class MoviesViewModel @Inject constructor(private val mapper: MoviesUIMapper) :  ViewModel() {
    private val _actionFlow =
        MutableSharedFlow<MoviesAction>(extraBufferCapacity = 16)

    init {
        _actionFlow.process().launchIn(viewModelScope)
    }

    private fun Flow<MoviesAction>.process() = onEach {
        when(it) {
            is MoviesAction.SearchMovieAction -> onSearchMovie(it.query)
            is MoviesAction.AddToHistoryAction -> onAddToHistory(it.movieId)
            MoviesAction.RefreshMoviesAction -> onRefreshMovies()
        }
    }
    
    /**
     * This is the only function exposed to the view.
     */
    fun processAction(action: MoviesAction) = _actionFlow.tryEmit(action)
}