class LoginActivity: AppCompatActivity(), LoginContract.View {

  var mPresenter: LoginContract.Presenter? = LoginPresenter(this)

  override fun onCreate() {
    loginBtn.setOnClickListener { onLoginButtonClicked() }
  }

  override fun onLoginButtonClicked() {
    mPresenter?.onLoginBtnPressed(etUsername.text, etPassword.text)
  }

  override fun goToOtpPage(userId: String) {
    val intent = Intent(view, OtpActivity::class.java)
    intent.putExtra(Constants.IntentExtras.USERID, userId)
    startActivity(intent)
  }

  override fun showError(message: String) {
    toast("Error: {$message}")
  }
}

class LoginPresenter(var view: LoginContract.View?): LoginContract.Presenter, LoginContract.InteractorOutput {
    var mInteractor: LoginContract.Interactor? = LoginInteractor(this)

    fun onLoginButtonPressed(username: String, password: String) {
      mInteractor?.login(username, password)
    }

    fun onLoginSuccess(user: User) {
      view?.goToNextScreen(user)
    }

    fun onLoginError(message: String) {
      view?.showError(message)
    }
}

class LoginInteractor(var mOutput: LoginContract.InteractorOutput?): LoginContract.Interactor {
  fun login(username: String, password: String) {
    mRepository.login(username, password)
                ?.subscribeOn(Schedulers.io())
                ?.observeOn(AndroidSchedulers.mainThread())
                ?.subscribe({
                   //do something here, like save it to db
                    mOutput?.onLoginSuccess(it)
                },{
                    mOutput?.onLoginError(it.message ?: "Error!")
                })
  }
}