ProjectNotificationViewModel.java

package com.kickstarter.viewmodels;

import android.support.annotation.NonNull;

import com.kickstarter.libs.ActivityViewModel;
import com.kickstarter.libs.Environment;
import com.kickstarter.models.ProjectNotification;
import com.kickstarter.services.ApiClientType;
import com.kickstarter.ui.viewholders.ProjectNotificationViewHolder;
import com.kickstarter.viewmodels.errors.ProjectNotificationViewModelErrors;
import com.kickstarter.viewmodels.inputs.ProjectNotificationViewModelInputs;
import com.kickstarter.viewmodels.outputs.ProjectNotificationViewModelOutputs;

import rx.Notification;
import rx.Observable;
import rx.subjects.BehaviorSubject;
import rx.subjects.PublishSubject;

import static com.kickstarter.libs.rx.transformers.Transformers.errors;
import static com.kickstarter.libs.rx.transformers.Transformers.takePairWhen;
import static com.kickstarter.libs.rx.transformers.Transformers.values;

public class ProjectNotificationViewModel extends ActivityViewModel<ProjectNotificationViewHolder> implements
  ProjectNotificationViewModelInputs, ProjectNotificationViewModelOutputs, ProjectNotificationViewModelErrors {
  public ProjectNotificationViewModel(final @NonNull Environment environment) {
    super(environment);

    final ApiClientType client = environment.apiClient();

    // When the enable switch is clicked, update the project notification.
    final Observable<Notification<ProjectNotification>> updateNotification = projectNotification
      .compose(takePairWhen(enabledSwitchClick))
      .switchMap(ne ->
        client
          .updateProjectNotifications(ne.first, ne.second)
          .materialize()
      )
      .share();

    updateNotification
      .compose(values())
      .compose(bindToLifecycle())
      .subscribe(projectNotification::onNext);

    updateNotification
      .compose(errors())
      .compose(bindToLifecycle())
      .subscribe(__ -> showUnableToSaveProjectNotificationError.onNext(null));

    // Update the project name when a project notification emits.
    projectNotification
      .map(n -> n.project().name())
      .compose(bindToLifecycle())
      .subscribe(projectName::onNext);

    // Update the enabled switch when a project notification emits.
    projectNotification
      .map(n -> n.email() && n.mobile())
      .compose(bindToLifecycle())
      .subscribe(enabledSwitch::onNext);
  }

  private PublishSubject<Boolean> enabledSwitchClick = PublishSubject.create();
  private PublishSubject<ProjectNotification> projectNotification = PublishSubject.create();

  private BehaviorSubject<String> projectName = BehaviorSubject.create();
  private BehaviorSubject<Boolean> enabledSwitch = BehaviorSubject.create();

  private PublishSubject<Void> showUnableToSaveProjectNotificationError = PublishSubject.create();

  public ProjectNotificationViewModelInputs inputs = this;
  public ProjectNotificationViewModelOutputs outputs = this;
  public ProjectNotificationViewModelErrors errors = this;

  @Override
  public void enabledSwitchClick(final boolean enabled) {
    enabledSwitchClick.onNext(enabled);
  }

  @Override
  public void projectNotification(final @NonNull ProjectNotification projectNotification) {
    this.projectNotification.onNext(projectNotification);
  }

  @Override
  public @NonNull Observable<String> projectName() {
    return projectName;
  }

  @Override
  public @NonNull Observable<Boolean> enabledSwitch() {
    return enabledSwitch;
  }

  @Override
  public @NonNull Observable<Void> showUnableToSaveProjectNotificationError() {
    return showUnableToSaveProjectNotificationError;
  }
}