TrustedLoginUserUseCase.kt

class TrustedLoginUserUseCase @Inject constructor(
    private val authTokenStorage: AuthTokenStorage,
    private val repository: AuthRepository,
    private val secureRandom: SecureRandom,
    schedulersFactory: SchedulersFactory
) : CompletableUseCase(schedulersFactory) {
  
    override fun sourceImpl(params: Params): Completable {
        val pinCode = params.require<String>(PARAM_KEY_REG_PIN_CODE)

        return step1(pinCode)
            .flatMap { step2(it) }
            .flatMapCompletable { step3(it) }
            .doOnComplete { trustedAuthSession = null }
    }
    
    internal fun step1(pinCode: String): Single<PreLoginTrustedItem> {
        // logic
    }

    internal fun step2(data: PreLoginTrustedItem): Single<LoginItem> {
        // logic
    }

    internal fun step3(data: LoginItem): Completable {
        // logic
    }
}