package com.reactnativejitsimeet;

import com.facebook.react.bridge.ReadableMap;

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;

class RNOngoingConferenceTracker {
  private static final RNOngoingConferenceTracker instance = new RNOngoingConferenceTracker();

  private static final String CONFERENCE_WILL_JOIN = "CONFERENCE_WILL_JOIN";
  private static final String CONFERENCE_TERMINATED = "CONFERENCE_TERMINATED";

  private final Collection<OngoingConferenceListener> listeners =
    Collections.synchronizedSet(new HashSet<>());
  private String currentConference;

  public RNOngoingConferenceTracker() {
  }

  public static RNOngoingConferenceTracker getInstance() {
    return instance;
  }

  synchronized String getCurrentConference() {
    return currentConference;
  }

  synchronized void onExternalAPIEvent(String name, ReadableMap data) {
    if (!data.hasKey("url")) {
      return;
    }

    String url = data.getString("url");
    if (url == null) {
      return;
    }

    switch (name) {
      case CONFERENCE_WILL_JOIN:
        currentConference = url;
        updateListeners();
        break;

      case CONFERENCE_TERMINATED:
        if (url.equals(currentConference)) {
          currentConference = null;
          updateListeners();
        }
        break;
    }
  }

  void addListener(OngoingConferenceListener listener) {
    listeners.add(listener);
  }

  void removeListener(OngoingConferenceListener listener) {
    listeners.remove(listener);
  }

  private void updateListeners() {
    synchronized (listeners) {
      for (OngoingConferenceListener listener : listeners) {
        listener.onCurrentConferenceChanged(currentConference);
      }
    }
  }

  public interface OngoingConferenceListener {
    void onCurrentConferenceChanged(String conferenceUrl);
  }
}