import { AppState } from 'react-native';
import Timer from './timer';

let pageTimerSet = new Set<Timer>();
AppState.addEventListener('change', (state) => {
  pageTimerSet.forEach((timer) => {
    if (!timer) {
      return;
    }
    if (state === 'active') {
      timer.resume();
    } else if (state === 'background') {
      timer.pause();
    }
  });
});

export default {
  buildPageTimer(): Timer {
    const timer = new Timer();
    pageTimerSet.add(timer);
    return timer;
  },
  removePageTimer(timer: Timer) {
    pageTimerSet.delete(timer);
  },
};