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

const mergeProducts = (
  productA: RetailerProductDataWithIdentifiers,
  productB: RetailerProductDataWithIdentifiers
): RetailerProductDataWithIdentifiers => {
  return Object.assign(productA, {
    ...productB,
    data: {
      ...productB.data,
      imageUrls: union(productA.data.imageUrls, productB.data.imageUrls),
    },
    productIdentifiers: union(
      productA.productIdentifiers,
      productB.productIdentifiers
    ),
  });
};

export const mergeDuplicatesByIdentifiers = (
  products: RetailerProductDataWithIdentifiers[]
): RetailerProductDataWithIdentifiers[] => {
  const uniqueProducts = new Array<RetailerProductDataWithIdentifiers>();
  products.forEach((product) => {
    const matchIndex = uniqueProducts.findIndex(
      ({ productIdentifiers, retailer }) =>
        retailer === product.retailer &&
        intersection(productIdentifiers, product.productIdentifiers).length > 0
    );

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

  return uniqueProducts;
};