import { intersection, union } from 'lodash';
import { AggregateProductDataWithIdentifiers } from './types';

const mergeProducts = <T extends AggregateProductDataWithIdentifiers>(
  productA: T,
  productB: T
): T => {
  return Object.assign(productA, {
    ...productB,
    data: {
      ...productB.data,
      imageUrls: union(productA.data.imageUrls, productB.data.imageUrls),
    },
    identifiers: union(productA.identifiers, productB.identifiers),
  });
};

export const mergeDuplicatesByIdentifiers = <
  T extends AggregateProductDataWithIdentifiers
>(
  products: T[]
): T[] => {
  const uniqueProducts = new Array<T>();
  products.forEach((product) => {
    const matchIndex = uniqueProducts.findIndex(
      ({ identifiers }) =>
        intersection(identifiers, product.identifiers).length > 0
    );

    if (matchIndex >= 0) {
      uniqueProducts[matchIndex] = mergeProducts(
        uniqueProducts[matchIndex],
        product
      );
    } else {
      uniqueProducts.push(product);
    }
  });

  return uniqueProducts;
};