Xây dựng lớp CarViewModel.java - Ví lập trình android quản lý car

package com.vantinviet.adayroionline.viewmodel.car;
import com.vantinviet.adayroionline.ApiResponse.ApiResponseGetCar;
import com.vantinviet.adayroionline.ApiResponse.ApiResponseUser;
import com.vantinviet.adayroionline.Config;
import com.vantinviet.adayroionline.repository.car.CarRepository;
import com.vantinviet.adayroionline.utils.AbsentLiveData;
import com.vantinviet.adayroionline.utils.Utils;
import com.vantinviet.adayroionline.viewmodel.common.PSViewModel;
import com.vantinviet.adayroionline.viewmodel.order.OrderProductListViewModel;
import com.vantinviet.adayroionline.viewobject.Car;
import com.vantinviet.adayroionline.viewobject.User;
import com.vantinviet.adayroionline.viewobject.common.Resource;

import java.util.List;

import javax.inject.Inject;

import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.Transformations;

public class CarViewModel extends PSViewModel {
    private final LiveData<Resource<List<Car>>> carsData;
    private MutableLiveData<TmpDataHolder> carsObj = new MutableLiveData<>();
    private MutableLiveData<Car> updateCarObj = new MutableLiveData<>();
    private LiveData<Resource<ApiResponseGetCar>> updateCarData;
    private final LiveData<Resource<Boolean>> deletedCar;
    private final LiveData<Resource<Boolean>> nextPageCarsData;
    private MutableLiveData<TmpDataHolder> nextPageCarsObj = new MutableLiveData<>();

    private final LiveData<Resource<Car>> carByIdData;
    private MutableLiveData<CarByIdTmpDataHolder> carByIdObj = new MutableLiveData<>();
    private MutableLiveData<CarViewModel.TmpDeleteCarDataHolder> tmpDeleteCarDataHolder = new MutableLiveData<>();

    public Car car;

    @Inject
    CarViewModel(CarRepository carRepository) {

        carsData = Transformations.switchMap(carsObj, obj -> {

            if (obj == null) {
                return AbsentLiveData.create();
            }

            return carRepository.getAllCar(obj.limit, obj.offset);

        });

        nextPageCarsData = Transformations.switchMap(nextPageCarsObj, obj -> {

            if (obj == null) {
                return AbsentLiveData.create();
            }

            return carRepository.getNextPageCarList( obj.limit, obj.offset);

        });

        carByIdData = Transformations.switchMap(carByIdObj, obj -> {

            if (obj == null) {
                return AbsentLiveData.create();
            }

            return carRepository.getCarById(obj.id);

        });
        // Update User
        updateCarData = Transformations.switchMap(updateCarObj, obj -> {
            if (obj == null) {
                return AbsentLiveData.create();
            }
            Utils.psLog("UserViewModel : updateUserData");
            return carRepository.updateCar(updateCarObj.getValue());
        });
        deletedCar = Transformations.switchMap(tmpDeleteCarDataHolder, tmpDeleteOrderDataHolder -> {
            if (tmpDeleteOrderDataHolder == null) {
                return AbsentLiveData.create();
            }
            return carRepository.getCarDelete(tmpDeleteCarDataHolder.getValue().carId);
        });


    }

    public void setCarsObj(String limit, String offset) {
        TmpDataHolder tmpDataHolder = new TmpDataHolder(limit, offset);

        this.carsObj.setValue(tmpDataHolder);
    }

    public LiveData<Resource<List<Car>>> getCarsData() {
        return carsData;
    }

    public void setNextPageCarsObj(String limit, String offset) {
        TmpDataHolder tmpDataHolder = new TmpDataHolder(limit, offset);

        this.nextPageCarsObj.setValue(tmpDataHolder);
    }

    public LiveData<Resource<Boolean>> getNextPageCarsData() {
        return nextPageCarsData;
    }

    public void setCarByIdObj(String id) {
        CarByIdTmpDataHolder carByIdTmpDataHolder = new CarByIdTmpDataHolder(id);

        this.carByIdObj.setValue(carByIdTmpDataHolder);
    }

    public LiveData<Resource<Car>> getCarByIdData() {
        return carByIdData;
    }
    public void setUpdateCarObj(Car car) {
        updateCarObj.setValue(car);
    }
    public LiveData<Resource<ApiResponseGetCar>> getUpdateCarData() {

        return updateCarData;
    }
    public LiveData<Resource<Boolean>> getDeletedCar() {
        return deletedCar;
    }
    public void setDeleteCarObj(String carId) {
        if (!isLoading) {
            CarViewModel.TmpDeleteCarDataHolder tmpDeleteCarDataHolder = new CarViewModel.TmpDeleteCarDataHolder();
            tmpDeleteCarDataHolder.carId = carId;
            this.tmpDeleteCarDataHolder.setValue(tmpDeleteCarDataHolder);
            // start loading
            setLoadingState(true);
        }
    }
    class TmpDataHolder {

        String  limit, offset;

        public TmpDataHolder(String limit, String offset) {
            this.limit = limit;
            this.offset = offset;
        }
    }

    class CarByIdTmpDataHolder {

        String id;

        private CarByIdTmpDataHolder(String id) {
            this.id = id;
        }
    }
    class TmpDeleteCarDataHolder {
        public String carId = "";
        public Boolean isConnected = false;
    }
}