import { all, put, take, takeEvery } from 'redux-saga/effects';
import { eventChannel } from 'redux-saga';
import { auth, firestore } from 'firebase';
import { addUserInfo, updateUserAuthedData, User } from 'state/actions/user';
import { errorOccurred } from 'state/actions/common';
import { UserActionTypes } from 'state/types/user';

let userAuthedDataChannel: any;

function* syncUserAuthedData({ type, payload }: { type: string; payload: User }) {
  // this statement prevent subscription when there is no uid and cancel subscription after user logged out
  if (payload.uid === '') {
    // if (userAuthedDataChannel) userAuthedDataChannel.close();
    return;
  }
  const ref = firestore()
    .collection('users')
    .doc(payload.uid)
    .collection('userData')
    .doc('authedData');
  userAuthedDataChannel = eventChannel(emit => ref.onSnapshot(emit));

  try {
    while (true) {
      const data = yield take(userAuthedDataChannel);
      yield put(updateUserAuthedData(data));
    }
  } catch (e) {
    yield put(errorOccurred(e.code));
  }
}

function* syncUserAuthedDataWatcher() {
  yield takeEvery(UserActionTypes.USER_INFO, syncUserAuthedData);
}

function* userStateWorker() {
  const channel = eventChannel(emit =>
    auth().onAuthStateChanged(user => {
      if (!user) return emit({});
      return emit(user);
    }),
  );

  try {
    while (true) {
      const user = yield take(channel);
      yield put(addUserInfo({ displayName: user.displayName || null, uid: user.uid || '' }));
    }
  } catch (e) {
    debugger
    yield put(errorOccurred(e.code));
  }
}

export default function* userSaga() {
  yield all([syncUserAuthedDataWatcher(), userStateWorker()]);
}