问想要在我的聊天应用程序中添加组聊天功能，使用react本机天赋-聊天库和firebase。

EN

const [roomName, setRoomName] = useState('');

const createRoom = () => {
if (roomName.length > 0) {
  firestore()
    .collection('THREADS')
    .add({
      name: roomName,
      latestMessage: {
        text: `You have joined the room ${roomName}.`,
        createdAt: new Date().getTime(),
      },
    })
    .then(docRef => {
      docRef.collection('MESSAGES').add({
        text: `You have joined the room ${roomName}.`,
        createdAt: new Date().getTime(),
        system: true,
      });
    });
}};

const [messages, setMessages] = useState([]);

const {thread} = route.params;

useEffect(() => {
const messagesListener = firestore()
  .collection('THREADS')
  .doc(thread._id)
  .collection('MESSAGES')
  .orderBy('createdAt', 'desc')
  .onSnapshot(querySnapshot => {
    const messages = querySnapshot.docs.map(doc => {
      const firebaseData = doc.data();

      const data = {
        _id: doc.id,
        text: '',
        createdAt: new Date().getTime(),
        ...firebaseData,
      };

      if (!firebaseData.system) {
        data.user = {
          ...firebaseData.user,
          name: firebaseData.user.email,
        };
      }

      return data;
    });

    setMessages(messages);
  });

return () => messagesListener();
}, []);