public class MainViewModel extends AndroidViewModel {

    private static SomethingDatabase database;
    private LiveData<List<Something>> something;

    public MainViewModel(@NonNull Application application) {
        super(application);
        database = SomethingDatabase.getInstance(getApplication());
        something = database.somethingDao().getAllSomething();
    }

    public Something getSomethingById(int id) {
        try {
            return new GetSomethingTask().execute(id).get();
        } catch (ExecutionException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return null;
    }

    public void deleteAllSomething() {
        new DeleteSomethingTask().execute();
    }

    public void insertSomething(Something something) {
        new InsertTask().execute(something);
    }

    public void deleteSomething(Something something) {
        new DeleteTask().execute(something);
    }

    public LiveData<List<Something>> getSomething() {
        return something;
    }

    private static class DeleteTask extends AsyncTask<Something, Void, Void> {
        @Override
        protected Void doInBackground(Something... something) {
            if (something != null && something.length > 0) {
                database.somethingDao().deleteSomething(something[0]);
            }
            return null;
        }
    }

    private static class InsertTask extends AsyncTask<Something, Void, Void> {
        @Override
        protected Void doInBackground(Something... something) {
            if (something != null && something.length > 0) {
                database.somethingDao().insertSomething(something[0]);
            }
            return null;
        }
    }

    private static class DeleteSomethingTask extends AsyncTask<Void, Void, Void> {
        @Override
        protected Void doInBackground(Void... integers) {
            database.somethingDao().deleteAllSomething();
            return null;
        }
    }

    private static class GetSomethingTask extends AsyncTask<Integer, Void, Something> {
        @Override
        protected Something doInBackground(Integer... integers) {
            if (integers != null && integers.length > 0) {
                return database.somethingDao().getSomethingById(integers[0]);
            }
            return null;
        }
    }
}