Serverless function to handle oauth

oauth-callback.js

const axios = require('axios');
const qs = require('qs');

exports.handler = async function(event, context) {
  // Parse the 'code' from the query string
  const { code } = event.queryStringParameters;

  // Token endpoint for your service, this should be replaced with your actual token endpoint
  const tokenURL = 'https://auth.smartcar.com/oauth/token';

  // The client_id and client_secret for your application on the service
  const client_id = process.env.CLIENT_ID;
  const client_secret = process.env.CLIENT_SECRET;

  try {
    // Send a POST request to the token endpoint
    const response = await axios.post(
      tokenURL,
      qs.stringify({
        client_id,
        client_secret,
        code,
        grant_type: 'authorization_code',
        redirect_uri: `${process.env.REDIRECT_URI}/api/oauth-callback`, //must match in Smartcar dashboard
      }),
      {
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded'
        }
      }
    );
      console.log('response...', response.data);
    // Extract the access_token from the response
    const { access_token, refresh_token, expires_in } = response.data;
      // When the token is received

    // Redirect to the specified URL with the token appended as a query parameter
    return {
      statusCode: 302,
      headers: {
        Location: `${process.env.REDIRECT_URI}?access_token=${access_token}&refresh_token=${refresh_token}&expires_in=${expires_in}`
      }
    };
  } catch (error) {
    console.error('Error exchanging code for token:', error);

    // Respond with a 500 status code (Server Error) if anything went wrong
    return {
      statusCode: 500,
      body: JSON.stringify({ error: 'Server Error' })
    };
  }
};

oauth.js

const axios = require('axios');
const qs = require('qs');

exports.handler = async function(event, context) {

  const { code } = event.queryStringParameters;
  const tokenURL = 'https://auth.smartcar.com/oauth/token';
  const client_id = process.env.DEMO_CLIENT_ID;
  const client_secret = process.env.DEMO_CLIENT_SECRET;
  const redirect_uri = process.env.DEMO_REDIRECT_URI;

  console.log('code...', code);
  console.log('client_id...', client_id);
  console.log('client_secret...', client_secret);
  console.log('redirect_uri...', redirect_uri);

  try {
    const response = await axios.post(
      tokenURL,
      qs.stringify({
        client_id,
        client_secret,
        code,
        grant_type: 'authorization_code',
        redirect_uri,
      }),
      {
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded'
        }
      }
    );
    console.log('response...', response.data);
    const { access_token, refresh_token, expires_in } = response.data;

    return {
      statusCode: 200,
      body: JSON.stringify({ access_token, refresh_token, expires_in })
    }
  } catch (error) {
    console.error('Error exchanging code for token:', error);

    // Respond with a 500 status code (Server Error) if anything went wrong
    return {
      statusCode: 500,
      body: JSON.stringify({ error: 'Server Error' })
    };
  }
};