class WaybillConfirmationViewModel @Inject constructor(
    private val router: Router,
    private val interactor: DriverInteractor,
    private val mapper: WaybillConfirmationMapper
) : BaseViewModel<WaybillConfirmationViewModel.State,
        WaybillConfirmationViewModel.Intent,
        WaybillConfirmationViewModel.Error>() {

    override fun bindIntents(viewIntents: Observable<Intent>): Observable<State> {
        val intentsViewStates = viewIntents
            .flatMap {
                when (it) {
                    Intent.LOAD_WAYBILL -> loadWaybill()
                    Intent.SEND_GO_LATER_STATUS -> sendGoLaterStatus()
                    Intent.SEND_READY_STATUS -> sendReadyStatus()
                }
            }

        return Observable
            .merge(loadWaybill(), intentsViewStates)
            .startWith(State(isLoading = true, noWaybill = false))
    }

    private fun loadWaybill(): Observable<State> {
        return interactor
            .getWaybill()
            .toObservable()
            .map { mapper.mapToState(it) }
            .startWith(viewState.copy(isLoading = true))
            .onErrorReturn {
                if (it !is NoWaybillException) {
                    sendEvent(Error.WAYBILL_LOADING_ERROR)
                }

                State(isLoading = false, noWaybill = true)
            }
    }

    private fun sendReadyStatus(): Observable<State> {
        return interactor
            .sendReadyToRideStatus()
            .andThen(Observable.just(viewState.copy(isLoading = false)))
            .onErrorReturnItem(viewState.copy(isLoading = false))
            .doOnError { sendEvent(Error.STATUS_SENDING_ERROR) }
            .startWith(Observable.just(viewState.copy(isLoading = true)))
    }

    private fun sendGoLaterStatus(): Observable<State> {
        return Completable
            .fromAction { router.navigateTo(Screen.GoLaterScreen()) }
            .andThen(Observable.just(viewState.copy(isLoading = false)))
    }

    data class State(
        val isLoading: Boolean,
        val noWaybill: Boolean,
        val departurePlace: String? = null,
        val invoiceDate: String? = null,
        val invoiceTime: String? = null,
        val scheduledShiftEndDate: String? = null,
        val scheduledShiftEndTime: String? = null
    )

    enum class Intent {
        LOAD_WAYBILL,
        SEND_GO_LATER_STATUS,
        SEND_READY_STATUS
    }

    enum class Error {
        WAYBILL_LOADING_ERROR,
        STATUS_SENDING_ERROR
    }
}