import { ApolloError } from '@apollo/client/core';
import { readable } from 'svelte/store';
import { client } from '$config/apollo';

/*
 * This is a generic store for use with apollo
 */

export const store = function store({ key, query, initialValue = null, variables = {} }) {

  return readable({
    loading: true,
    data: initialValue,
    error: undefined
  }, (set) => {

    const handleError = function (error) {

      return set({
        loading: false,
        data: initialValue,
        error
      });
    };

    client.watchQuery({ query, variables }).subscribe((result) => {

      if (result.errors) {
        const error = new ApolloError({ graphQLErrors: result.errors });
        return handleError(error);
      }

      set({
        loading: false,
        data: result.data[key],
        error: undefined
      });
    }, (error) => handleError(error));
  });
};