import { useState } from 'react';
import { useQuery } from '@apollo/client';
import update from 'immutability-helper';
import get from 'lodash/get';

export const usePagerQuery = (
  query,
  { variables, updateQuery, itemsPath, countPath, skip }
) => {
  const [loadingMore, setLoadingMore] = useState(false);

  const { data, loading, fetchMore } = useQuery(query, {
    variables,
    skip
  });

  const items = get(data, itemsPath, []);
  const total = get(data, countPath, 0);
  const count = items.length;
  const hasNextPage = count !== total;

  const loadMore = async () => {
    setLoadingMore(true);

    const result = await fetchMore({
      query,
      variables: {
        ...variables,
        skip: count
      },
      updateQuery: (previousResult, { fetchMoreResult }) => {
        if (!fetchMoreResult) {
          return previousResult;
        }
        return update(previousResult, updateQuery(fetchMoreResult));
      }
    });

    setLoadingMore(false);

    return result;
  };

  return {
    data,
    items,
    total,
    count,
    loading,
    loadMore,
    hasNextPage,
    loadingMore
  };
};