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

const mergeProductVariants = <
  T extends AggregateProductVariantDataWithIdentifiers
>(
  productA: T,
  productB: T
): T => {
  return Object.assign(productA, {
    ...productB,
    data: {
      ...productB.data,
      imageUrls: union(productA.data.imageUrls, productB.data.imageUrls),
    },
    productIdentifiers: union(
      productA.productIdentifiers,
      productB.productIdentifiers
    ),
    variantIdentifiers: union(
      productA.variantIdentifiers,
      productB.variantIdentifiers
    ),
  });
};

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

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

  return uniqueProducts;
};