如何从firebase函数中删除最后一个文档

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

exports.deleteLastDocument = functions.https.onRequest(async (req, res) => {
  try {
    const collectionRef = admin.firestore().collection('your-collection');
    const snapshot = await collectionRef.orderBy('createdAt', 'desc').limit(1).get();
    
    if (snapshot.empty) {
      res.status(404).send('No documents found.');
      return;
    }
    
    const lastDocument = snapshot.docs[0];
    await lastDocument.ref.delete();
    
    res.status(200).send('Last document deleted successfully.');
  } catch (error) {
    console.error('Error deleting document:', error);
    res.status(500).send('Error deleting document.');
  }
});