export function* channelSaga(session: ISession): SagaIterator {
    const channel: IChannel = yield call(getChannel, session.id, session.mode);
    yield call([channel, channel.start], session.id);

    yield put(connected());

    try {
        yield all([
            call(channelListenerSaga, channel),
            call(channelSenderSaga, session.id, channel)
        ]);
    } finally {
        if (yield cancelled()) {
            yield call([channel, channel.end]);
        }
    }
}

  return function*(repoUri: RepositoryUri) {
    try {
      while (true) {
        // Delay at the beginning to allow some time for the server to consume the
        // queue task.
        yield call(delay, REPO_STATUS_POLLING_FREQ_MS);

        const repoStatus = yield call(fetchStatus, repoUri);
        const keepPolling = yield handleStatus(repoStatus, repoUri);
        if (!keepPolling) {
          yield put(pollingStopActionFunction(repoUri));
        }
      }
    } finally {
      if (yield cancelled()) {
        // Do nothing here now.
      }
    }
  };

function* timer() {
  try {
    yield put(actions.setBotFrozenTimeout(5e3))
    while (true) {
      const { delta }: actions.Tick = yield take(actions.A.Tick)
      const {
        game: { botFrozenTimeout },
      }: State = yield select()
      if (botFrozenTimeout === 0) {
        break
      }
      const next = botFrozenTimeout - delta
      yield put(actions.setBotFrozenTimeout(next <= 0 ? 0 : next))
    }
  } finally {
    if (yield cancelled()) {
      yield put(actions.setBotFrozenTimeout(0))
    }
  }
}

function* animateCurtainAndLoadMap(stage: StageConfig) {
  try {
    yield put(actions.updateComingStageName(stage.name))
    yield put(actions.updateCurtain('stage-enter-curtain', 0))

    yield* Timing.tween(f(30), t => put(actions.updateCurtain('stage-enter-curtain', t)))

    // 在幕布完全将舞台遮起来的时候载入地图
    yield Timing.delay(f(20))
    yield put(actions.playSound('stage_start'))
    yield put(actions.loadStageMap(stage))
    yield Timing.delay(f(20))

    yield* Timing.tween(f(30), t => put(actions.updateCurtain('stage-enter-curtain', 1 - t)))
    // todo 游戏开始的时候有一个 反色效果
  } finally {
    if (yield cancelled()) {
      // 将幕布隐藏起来
      yield put(actions.updateCurtain('stage-enter-curtain', 0))
    }
  }
}

function* testCancelled(): SagaIterator {
  yield cancelled();
  // typings:expect-error
  yield cancelled(1);
}