MainViewModel.kt

class MainViewModel (private val stateReducer: StateReducer,
                     private val countryRepository: CountryRepository
) : ViewModel(), MainView {

    private val bigCards: LiveData<List<Card>> = Transformations.map(countryRepository.getAll()) { countries ->
        return@map countries.map { country ->
            Card(country.id!!, country.name, country.imageUrl, country.description)
        }
    }

    private val topCarousel: LiveData<List<CarouselItem>> = Transformations.map(countryRepository.getAll()) { countries ->
        return@map countries.map { country ->
            CarouselItem(country.id!!, country.name, country.description)
        }
    }

    private val bottomCarousel: LiveData<List<CarouselItem>> = Transformations.map(countryRepository.getAll()) { countries ->
        return@map countries.map { country ->
            CarouselItem(country.id!!, country.name, country.description)
        }
    }
    
    private val mediator = MediatorLiveData<List<DataWrapper>>().apply {
        addSource(topCarousel) { stateReducer.onTopCarouselLoaded(it) }
        addSource(bigCards) { stateReducer.onCardsLoaded(it) }
        addSource(bottomCarousel) { stateReducer.onBottomCarouselLoaded(it) }
        addSource(stateReducer.getData()) { t: List<DataWrapper>? -> value = t }
    }


    fun getData(): LiveData<List<DataWrapper>> = mediator

}