import { config as setupEnv } from 'dotenv-flow';
import connect from '@/config/db';
import { Page, Product } from '@/entities';
import { TypeormDataLoader } from '@/entities/utils';
import logger from '@/logger';
import { ContextType } from '@/types';
setupEnv();

const main = async () => {
  await connect();
  let unupdatedProducts = new Array<Product>();
  let indexedProductCount = 0;
  const dbDataLoader = new TypeormDataLoader();

  const updateProducts = async () => {
    // uncomment to ensure too many pages don't get indexed
    // if (indexedPageCount > 10000) {
    //   stream.pause();
    //   stream.destroy();
    //   throw new Error('too many pages indexed');
    // }
    await Promise.all(
      unupdatedProducts.map(async (product) => {
        const context = { dbDataLoader } as ContextType;
        const lowestPricePage = await product.lowestPricePage(context);
        if (lowestPricePage) {
          return Page.update(
            {
              productFirebaseId: product.firebaseId,
            },
            {
              lowestPricePageId: lowestPricePage.id,
            }
          );
        }
      })
    );
    indexedProductCount = indexedProductCount + unupdatedProducts.length;
    logger.info(`updated ${indexedProductCount} products`);
    unupdatedProducts = [];
  };

  const stream = await Product.createQueryBuilder().stream();
  await new Promise((resolve, reject) => {
    stream.on('data', (pgProduct: Record<string, unknown>) => {
      const product = Product.create(
        Object.entries(pgProduct).reduce((prev, [key, value]) => {
          return {
            ...prev,
            [key.startsWith('Product_') ? key.slice(8) : key]: value,
          };
        }, {})
      );
      unupdatedProducts.push(product);

      if (unupdatedProducts.length >= 100) {
        stream.pause();
        updateProducts()
          .then(() => {
            stream.resume();
          })
          .catch((error) => {
            stream.destroy(error);
            reject(error);
          });
      }
    });
    stream.on('end', async () => {
      resolve(undefined);
      if (unupdatedProducts.length >= 0) {
        try {
          updateProducts().then(resolve);
        } catch (error) {
          stream.destroy();
          reject(error);
          throw error;
        }
      }
    });
  });
};

console.time('main');
main()
  .then(() => {
    console.timeEnd('main');
  })
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });