QueryBillViewModel.java

package net.lamtran.rxjava2.bill;

import android.text.TextUtils;

import java.util.List;

import rx.Observable;
import rx.android.schedulers.AndroidSchedulers;
import rx.schedulers.Schedulers;

/**
 * Created by lam on 9/27/16.
 */

public class QueryBillViewModel {

  private BillSharedData billSharedData;

  private String customerCode;

  private QueryBillUseCase mQueryBillUseCase;

  private QueryBillRequest mRequest;

  private List<Provider> providers;

  private Provider selectedProvider;

  private Service selectedService;

  private List<Service> services;

  public Observable<QueryBillRequest> buildRequest(RecentTransaction item) {
    return Observable.just(new QueryBillRequest.Builder())
        .flatMap(builder -> Observable.from(services)
            .filter(service -> TextUtils.equals(service.serviceId, item.serviceId))
            .doOnNext(service -> {
              billSharedData.service = service;
              builder.setServiceId(service.serviceId);
            })
            .flatMap(service -> Observable.from(service.providers)
                .filter(provider -> TextUtils.equals(provider.providerId, item.providerId))
                .doOnNext(provider -> {
                  billSharedData.provider = provider;
                  billSharedData.customerCode = item.customerId;
                  builder.setProviderId(provider.providerId);
                  builder.setCustomerId(item.customerId);
                }))
            .flatMap(provider -> Observable.just(builder.build())));
  }

  public void query(QueryBillRequest queryBillRequest) {
    Observable.just(queryBillRequest)
        .flatMap(request -> {
          if (request.equals(mRequest)) {
            return Observable.just(request);
          } else {
            billSharedData.service = selectedService;
            billSharedData.provider = selectedProvider;
            billSharedData.customerCode = customerCode;
            QueryBillRequest billRequest = new QueryBillRequest.Builder()
                .setServiceId(selectedService.serviceId)
                .setProviderId(selectedProvider.providerId)
                .setCustomerId(customerCode)
                .build();
            return Observable.just(billRequest);
          }
        })
        .doOnNext(request -> {
          mQueryBillUseCase.setRequest(request);
          billSharedData.queryBillRequest = request;
        })
        .flatMap(request -> mQueryBillUseCase.execute())
        .doOnNext(response -> billSharedData.queryBillResponse = response)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(response -> {

        }, throwable -> {

        });
  }

  private static class BillSharedData {

    public String customerCode;

    public Provider provider;

    public QueryBillRequest queryBillRequest;

    public QueryBillResponse queryBillResponse;

    public Service service;
  }

  private static class Provider {

    public String providerId;
  }

  private static class RecentTransaction {

    public String customerId;

    public String providerId;

    public String serviceId;
  }

  private static class Service {

    public List<Provider> providers;

    public String serviceId;
  }
}