import { chunk } from 'lodash';
import { In } from 'typeorm';
import { Page } from '@/entities';
import { sequence } from '@/utils';
import { CSVPage } from './types';

export default async (
  csvPages: CSVPage[],
  {
    afterInsert,
  }: {
    /**
     * Whether or not to run afterInsert listener after all pages are inserted.
     */
    afterInsert: boolean;
  }
): Promise<Page[]> => {
  const productLowestPriceMap = new Map<
    string,
    { price: number; pageId: string }
  >();
  csvPages.forEach((csvPage) => {
    const existing = csvPage.productFirebaseId
      ? productLowestPriceMap.get(csvPage.productFirebaseId)
      : undefined;
    if (!csvPage.productFirebaseId || !csvPage.id || !csvPage.price) {
      return;
    }
    if (!existing) {
      productLowestPriceMap.set(csvPage.productFirebaseId, {
        price: csvPage.price,
        pageId: csvPage.id,
      });
    } else if (existing.price > (csvPage.price ?? 0)) {
      productLowestPriceMap.set(csvPage.productFirebaseId, {
        price: csvPage.price,
        pageId: csvPage.id,
      });
    }
  });
  await sequence(
    chunk(
      csvPages
        .filter(
          ({ firebaseId, productFirebaseId, price, retailer, url }) =>
            firebaseId && productFirebaseId && price && retailer && url
        )
        .map(({ lowestPricePageId, productFirebaseId, ...rest }) => ({
          productFirebaseId,
          discoverable: true,
          ...rest,
        })),
      100
    ).map((pages) => async () => {
      await Page.insert(pages);
    })
  );
  // update lowest price pages
  await sequence(
    [...productLowestPriceMap.entries()].map(
      ([productFirebaseId, { pageId }]) =>
        async () => {
          await Page.update(
            {
              productFirebaseId,
            },
            {
              lowestPricePageId: pageId,
            }
          );
        }
    )
  );

  const pages = await Page.find({
    where: { id: In(csvPages.map(({ id }) => id)) },
  });
  if (afterInsert) {
    await Promise.all(pages.map((page) => page.afterInsert()));
  }
  return pages;
};