import { ApolloClient, createHttpLink, InMemoryCache } from '@apollo/client';
import { setContext } from '@apollo/client/link/context';

const httpLink = createHttpLink({
  uri: '/graphql',
});

const authLink = setContext((_, { headers }) => {
  // get the authentication token from local storage if it exists
  const token = localStorage.getItem('token');
  // return the headers to the context so httpLink can read them
  return {
    headers: {
      ...headers,
      authorization: token ? `Bearer ${token}` : "",
    }
  }
});

const client = new ApolloClient({
  link: authLink.concat(httpLink),
  cache: new InMemoryCache()
});

import { setContext } from "apollo-link-context";
import { onError } from "apollo-link-error";
 
// cached storage for the user token
// cached storage for the user token
let token;
const withToken = setContext(() => {
  // if you have a cached value, return it immediately
// if you have a cached value, return it immediately
  if (token) return { token };
 
  return AsyncTokenLookup().then(userToken => {
    token = userToken;
    return { token };
  });
});
 
const resetToken = onError(({ networkError }) => {
  if (networkError && networkError.name ==='ServerError' && networkError.statusCode === 401) {
    // remove cached token on 401 from the server
// remove cached token on 401 from the server
    token = null;
  }
});
 
const authFlowLink = withToken.concat(resetToken);

import { setContext } from "@apollo/client/link/context";
import { onError } from "@apollo/client/link/error";

// cached storage for the user token
let token;
const withToken = setContext(() => {
  // if you have a cached value, return it immediately
  if (token) return { token };

  return AsyncTokenLookup().then(userToken => {
    token = userToken;
    return { token };
  });
});

const resetToken = onError(({ networkError }) => {
  if (
    networkError &&
    networkError.name ==='ServerError' &&
    networkError.statusCode === 401
  ) {
    // remove cached token on 401 from the server
    token = null;
  }
});

const authFlowLink = withToken.concat(resetToken);

import { setContext } from "apollo-link-context";
 
const setAuthorizationLink = setContext((request, previousContext) => ({
  headers: {authorization: "1234"}
}));
 
const asyncAuthLink = setContext(
  request =>
    new Promise((success, fail) => {
      // do some async lookup here
// do some async lookup here
      setTimeout(() => {
        success({ token: "async found token" });
      }, 10);
    })
);

import { setContext } from "@apollo/client/link/context";

const setAuthorizationLink = setContext((request, previousContext) => ({
  headers: {authorization: "1234"}
}));

const asyncAuthLink = setContext(
  request =>
    new Promise((success, fail) => {
      // do some async lookup here
      setTimeout(() => {
        success({ token: "async found token" });
      }, 10);
    })
);