import { ApolloClient } from 'apollo-client'
import { InMemoryCache } from 'apollo-cache-inmemory'
import { HttpLink } from 'apollo-link-http'
import { onError } from 'apollo-link-error'
import { setContext } from 'apollo-link-context'
import { ApolloLink } from 'apollo-link'

const httpLink = new HttpLink({
  uri: process.env.REACT_APP_GRAPHQL_URI,
  credentials: 'same-origin',
})

const linkError = onError(({ graphQLErrors, networkError }) => {
  if (graphQLErrors)
    graphQLErrors.map(({ message, locations, path }) =>
      console.log(
        `[GraphQL error]: Message: ${message}, Location: ${locations}, Path: ${path}`
      )
    )
  if (networkError) console.log(`[Network error]: ${networkError}`)
})

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: ApolloLink.from([linkError, authLink.concat(httpLink)]),
  cache: new InMemoryCache(),
})

export default client