import { useMemo } from 'react';
import { ApolloClient, InMemoryCache, HttpLink, ApolloLink, NormalizedCacheObject } from '@apollo/client';
import { Storage } from 'react-jhipster';
let apolloClient: ApolloClient<NormalizedCacheObject> | undefined;

function createIsomorphLink() {
  const token = Storage.local.get('jhi-authenticationToken') || Storage.session.get('jhi-authenticationToken');
  return new HttpLink({
    uri: process.env.GRAPHQL_API_URL,
    // credentials: 'same-origin',
    headers: {
      Authorization: `Bearer ${token}` || null,
    },
  });
}

function createApolloClient() {
  return new ApolloClient({
    ssrMode: typeof window === 'undefined',
    link: ApolloLink.from([createIsomorphLink()]),
    cache: new InMemoryCache(),
  });
}

export function initializeApollo(initialState: any = null): any {
  const _apolloClient = apolloClient ?? createApolloClient();

  // If your page has Next.js data fetching methods that use Apollo Client, the initial state
  // gets hydrated here
  if (initialState) {
    // Get existing cache, loaded during client side data fetching
    const existingCache = _apolloClient.extract();
    // Restore the cache using the data passed from getStaticProps/getServerSideProps
    // combined with the existing cached data
    _apolloClient.cache.restore({ ...existingCache, ...initialState });
  }
  // For SSG and SSR always create a new Apollo Client
  if (typeof window === 'undefined') return _apolloClient;
  // Create the Apollo Client once in the client
  if (!apolloClient) apolloClient = _apolloClient;

  return _apolloClient;
}

export function useApollo(initialState: any): any {
  const store = useMemo(() => initializeApollo(initialState), [initialState]);
  return store;
}