egypt-banks-scraper/src/index.js

Scrape exchange rates from Egypt banks

import banksClasses from './banks';
import { getBrowser } from './browser';

const banksObjects = {};
banksClasses.forEach((Bank) => {
  const bankObject = new Bank();
  banksObjects[bankObject.name.acronym] = bankObject;
});

// get currency rate for currencyCode
function getCurrencyRates(rates, currencyCode) {
  for (let i = 0; i < rates.length; i += 1) {
    const filteredRate = rates[i].code === currencyCode ? rates[i] : undefined;
    if (filteredRate !== undefined) return filteredRate;
  }
  return null;
}

// get rates that have currency rate
function filterCurrencies(rates, currenciesCodes) {
  const filteredRates = [];
  currenciesCodes.forEach((code) => {
    const rate = getCurrencyRates(rates, code);
    if (rate === null) return;

    filteredRates.push(rate);
  });
  return filteredRates;
}

async function getExchangeRates(banks, currencies) {
  const browser = await getBrowser();
  const getRates = async (bank) => {
    try {
      const rates = await bank.scrape(browser);
      // If currencies array empty get all rates
      const filteredRates = currencies.length === 0
        ? rates : filterCurrencies(rates, currencies);
      return ({
        name: bank.name,
        rates: filteredRates,
      });
    } catch (e) {
      // console.log('error on get rates:', e);

      return ({
        name: bank.name,
        rates: [],
      });
    }
  };

  // If banks array empty get all banks names
  const filteredBanks = banks.length === 0 ? Object.keys(banksObjects) : banks;
  const result = {};
  let banksPromises = [];
  const ratesPromises = [];

  for (let i = 0; i < filteredBanks.length; i += 1) {
    const bankName = filteredBanks[i];
    const bank = banksObjects[bankName];

    if (bank) {
      ratesPromises.push(getRates(bank));
    }
  }
  banksPromises = await Promise.all(ratesPromises);

  banksPromises.forEach((value) => {
    result[value.name.acronym] = value;
  });
  await browser.close();
  return result;
}

// getExchangeRates(['AIB'], []).then((data) => {
//   console.log('data:', data);
// });

export {
  banksObjects,
  getExchangeRates,
};