Using google book API specific parameter to get smallTumbnail in the frontend of my ejs

Question

I am trying to use Google Book API for my project app which it's intention is; the user can search the title and author of a book that they have read and in response you will get the title and author and the cover image extracted from google book API.

I am able to get all the total items through the search title and author from the API but I can not specify to respond only the first item from the search and most importantly the smallThumbnail which will be the cover image for the search book.

I am using in the backend postgres as my db and ejs on my frontend.

I know the smallThumbnail is under volumeInfo which is under imageLinks, I just can not make it show in my front ejs

// Import necessary modules
const express = require('express');
const bodyParser = require('body-parser');
const axios = require('axios');
const { Client } = require('pg');
const path = require('path');

// Create Express app
const app = express();
const port = 3000;

// Middleware
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

// PostgreSQL Client
const client = new Client({
  user: process.env.DB_USER || 'postgres',
  host: process.env.DB_HOST || 'localhost',
  database: process.env.DB_NAME || 'book_notes_db',
  password: process.env.DB_PASSWORD || 'na',
  port: process.env.DB_PORT || 5432,
});

// Connect to PostgreSQL database
client.connect()
  .then(() => console.log('Connected to PostgreSQL database'))
  .catch(error => console.error('Error connecting to PostgreSQL database:', error));

// EJS Setup
app.set('view engine', 'ejs');
app.set('views', path.join(__dirname, 'views'));

// Serve static files from the public directory
app.use(express.static(path.join(__dirname, 'public')));

// Route for the root URL
app.get('/', async (req, res) => {
  try {
    const dbData = await fetchDataFromDatabase();
    const booksData = await fetchDataFromAPI(dbData);
    res.render('index', { dbData, booksData });
  } catch (error) {
    handleError(res, error);
  }
});

// POST a new book with title and author only
app.post('/books', async (req, res) => {
  console.log('Received data:', req.body);
  const { title, author } = req.body;
  try {
  

    // Update database with ISBN
    await client.query('INSERT INTO books (title, author) VALUES ($1, $2)', [title, author]);

    let image_link = null; // Initialize cover image URL


   

      // Update database with cover image URL if it's available
      if (image_link) {
        await client.query('UPDATE books SET image_link = $1 WHERE isbn = $2', [image_link, isbn]);
      }
    

    // Fetch data from the database
    const dbData = await fetchDataFromDatabase();
    
    // Render the page with updated data and the relevant book data
    const bookData = await fetchBookData(title, author,image_link); // Fetch additional book data
    res.status(201).render('index', { dbData, bookData }); // Pass both dbData and bookData to the template
  } catch (error) {
    handleError(res, error);
  }
});


// DELETE a book by ID
app.delete('/books/:book_id', async (req, res) => {
  const bookId = req.params.book_id;
  try {
    await client.query('DELETE FROM books WHERE book_id = $1', [bookId]);
    const dbData = await fetchDataFromDatabase();
    const booksData = await fetchDataFromAPI(dbData);
    res.status(200).json({ success: true, message: 'Book deleted successfully', data: dbData });
  } catch (error) {
    handleError(res, error);
  }
});

// Start the server
app.listen(port, () => {
  console.log(`Server is running on http://localhost:${port}`);
});

// Function to fetch data from the database
async function fetchDataFromDatabase() {
  const { rows: dbData } = await client.query('SELECT * FROM books');
  return dbData;
}

// Function to fetch additional data from the API
async function fetchDataFromAPI(dbData) {
  // Implement logic to fetch additional data from the API if needed
  // For now, return the original data
  return dbData;
}


async function fetchBookData(title, author) {
  const apiUrl = `https://www.googleapis.com/books/v1/volumes?q=intitle:${encodeURIComponent(title)}+inauthor:${encodeURIComponent(author)}&key=na`;
  try {
    const response = await axios.get(apiUrl);
    console.log('Google Books API response_bookData:', response.data.items);

    const items = response.data.items;
    if (!items || items.length === 0) {
      console.error('No books found for the given search criteria');
      return null;
    }

    // Extract data from the first item
    const firstItem = items[0];
     const volumeInfo = firstItem.volumeInfo;
    const bookData = {
      title: volumeInfo.title,
      author:volumeInfo.authors ? firstItem.volumeInfo.authors.join(', ') : 'Unknown Author',
      smallThumbnail:volumeInfo.imageLinks?.smallThumbnail || ''
    };

    return bookData;
  } catch (error) {
    console.error('Error fetching book data:', error);
    throw error; // Rethrow the error to be caught by the caller
  }
}

// Function to handle errors
function handleError(res, error) {
  console.error('Error:', error);
  res.status(500).json({ error: 'Internal Server Error' });
}