AWS AppSync Auth Link

import { ApolloClient, InMemoryCache, HttpLink } from '@apollo/client';
import { createAuthLink, AUTH_TYPE } from 'aws-appsync-auth-link';
import { createSubscriptionHandshakeLink } from 'aws-appsync-subscription-link';

// Replace with your AppSync endpoint and API key/region
const APPSYNC_URL = 'https://YOUR_APPSYNC_ID.appsync-api.YOUR_REGION.amazonaws.com/graphql';
const APPSYNC_REGION = 'us-east-1'; // e.g., 'us-east-1'
const APPSYNC_API_KEY = process.env.APPSYNC_API_KEY ?? 'da2-YOUR_APPSYNC_API_KEY';

// Configuration object for AppSync
const awsAppSyncConfig = {
  url: APPSYNC_URL,
  region: APPSYNC_REGION,
  auth: {
    type: AUTH_TYPE.API_KEY,
    apiKey: APPSYNC_API_KEY,
  },
};

// 1. Create the authentication link
const authLink = createAuthLink(awsAppSyncConfig);

// 2. Create the HTTP link for queries and mutations
const httpLink = new HttpLink({ uri: awsAppSyncConfig.url });

// 3. Create the subscription handshake link (required for real-time subscriptions)
// Note: aws-appsync-subscription-link is a separate package
const subscriptionLink = createSubscriptionHandshakeLink(awsAppSyncConfig);

// Chain the links in the correct order:
// authLink -> subscriptionLink (for WebSocket handshake) -> httpLink (for HTTP requests)
const link = authLink.concat(subscriptionLink).concat(httpLink);

// Initialize Apollo Client
const client = new ApolloClient({
  link: link,
  cache: new InMemoryCache(),
});

console.log('Apollo Client initialized with AWS AppSync authentication and subscription links.');
console.log('AppSync Endpoint:', awsAppSyncConfig.url);
console.log('Authentication Type:', awsAppSyncConfig.auth.type);

// Example of a basic query (requires 'graphql-tag' for gql template literal, not included here)
// import { gql } from '@apollo/client';
// client.query({
//   query: gql`
//     query MyQuery {
//       listItems {
//         items {
//           id
//           name
//         }
//       }
//     }
//   `
// }).then(response => console.log('Query Data:', response.data))
//   .catch(error => console.error('Query Error:', error));