PromotionListContract.kt

interface PromotionListContract {
    interface View : MvpView {
        fun listInit(): Observable<Any>
        fun render(viewState: ViewState)
    }

    abstract class Presenter : MviBasePresenter<View, ViewState>()

    data class ViewState(
            val promotionList: List<PromotionViewModel> = emptyList(),
            val showError: Boolean = false,
            val showLoading: Boolean = false,
            val error: Error = Error())

    interface Interactor {
        fun getPromotions(): Observable<PartialViewState>
    }

    sealed class PartialViewState {
        object Loading : PartialViewState()
        data class PromotionList(val list: List<PromotionViewModel>) : PartialViewState()
        data class Error(val reason: kotlin.Error) : PartialViewState()
    }
}