import {
  ApolloClient,
  InMemoryCache,
  gql,
  ApolloLink,
  concat,
  // useQuery,
  // createHttpLink,
  HttpLink
} from "@apollo/client";
import ApolloConfig from "../config/apollo-config";
// import fetch from "cross-fetch";

function errorHandler(object) {
  return object.graphQLErrors.length != 0
    ? object.graphQLErrors[0].message
    : object.networkError && object.networkError.result
    ? object.networkError.result.errors.join(" ; ")
    : object.networkError
    ? object.networkError[Object.keys(object.networkError)[0]].toString()
    : "Fetch failed";
}

function initApollo(token) {
  // const httpLink = createHttpLink({
  //   uri: ApolloConfig.graphql_uri,
  //   fetch: fetch,
  //   headers:
  //     token != ""
  //       ? {
  //           Authorization: `Bearer ${token}`,
  //         }
  //       : null,
  // });
  const httpLink = new HttpLink({ uri: ApolloConfig.graphql_uri });

  const authMiddleware = new ApolloLink((operation, forward) => {
      operation.setContext(({ headers = {} }) => token == ""?headers:({
        headers: {
          ...headers,
          Authorization: `Bearer ${token}`,
        }
      }));
      return forward(operation);
    })

  return new ApolloClient({
    cache: new InMemoryCache({
      addTypename: false,
    }),
    link: concat(authMiddleware, httpLink),
  });
}

async function query(query, token = "", variables = {}, cache = false) {
  const client = initApollo(token);
  var res;
  try {
    var sql = await client.query({
      query: gql`
        ${query}
      `,
      variables: variables,
      fetchPolicy: cache ? "cache-first" : "no-cache",
    });
    res = { STATUS: 1, DATA: sql.data };
  } catch (e) {
    console.log(e.message);
    res = { STATUS: 0, DATA: e.message };
  }
  return res;
}

async function mutation(mutation, token = "", variables = {}) {
  const client = initApollo(token);
  var res;
  try {
    var sql = await client.mutate({
      mutation: gql`
        ${mutation}
      `,
      variables: variables,
    });
    res = { STATUS: 1, DATA: sql.data };
  } catch (e) {
    console.log(e.message);
    res = { STATUS: 0, DATA: e.message };
  }
  return res;
}

module.exports = {
  query: query,
  mutation: mutation,
};