import ApolloClient, { Operation, ApolloQueryResult, FetchResult, FetchPolicy } from 'apollo-boost';
import fetch from 'isomorphic-fetch';

const Client = new ApolloClient({
  fetch,
  uri: process.env.FLOOMX_API_URL_X,
  request: async (operation: Operation): Promise<void> => {
    operation.setContext({
      headers: {
        'X-FloomX-Api': process.env.GATSBY_FLOOMX_TOKEN
      }
    });
  },
  onError: ({graphQLErrors, networkError, operation, forward}): void => {
    if (graphQLErrors) {
      for (const err of graphQLErrors) {
        // handle errors differently based on its error code
        console.log(err);
      }
    }

    if (networkError) {
      // handle errors differently based on its error code
      console.log(networkError);
    }
  }
});

export class GraphQL {
  static query(query: any, variables: object = {}, fetchPolicy: FetchPolicy = 'cache-first')
    : Promise<ApolloQueryResult<any>> {
    return Client.query({
      query,
      variables,
      fetchPolicy
    });
  }

  static mutate(
    mutation: any,
    variables: object = {},
    optimisticResponse: object = {}
  ): Promise<FetchResult<any>> {
    return Client.mutate({
      mutation,
      variables,
      optimisticResponse
    });
  }
}

export default GraphQL;