guilhermearaujo/boleto.js

const SVG = require('./svg');
const ITF = require('./itf');
const { modulo11 } = require('./helpers');

class Boleto {
  /**
   * Initializes the class
   *
   * @constructor
   * @param {String} bankSlipNumber The bank slip number
   */
  constructor(bankSlipNumber) {
    this.bankSlipNumber = bankSlipNumber.replace(/[^\d]/g, '');

    if (!this.valid()) {
      throw new Error('Invalid bank slip number');
    }
  }

  /**
   * Validates whether the bank slip number is valid or not
   *
   * The validation function ensures that the bank slip number is exactly 47
   * characters long, then applies the modulo-11 algorithm to the bank slip's
   * barcode. Finally, it verifies that the result of the algorithm equals the
   * checksum digit from the bank slip number.
   *
   * @return {Boolean} Whether the bank slip number is valid or not
   */
  valid() {
    if (this.bankSlipNumber.length !== 47) return false;

    const barcodeDigits = this.barcode().split('');
    const checksum = barcodeDigits.splice(4, 1);

    return (modulo11(barcodeDigits).toString() === checksum.toString());
  }

  /**
   * Converts the printed bank slip number into the barcode number
   *
   * The bank slip's number is a rearrangement of its barcode, plus three
   * checksum digits. This function executes the inverse process and returns the
   * original arrangement of the code. Specifications can be found at
   * https://portal.febraban.org.br/pagina/3166/33/pt-br/layour-arrecadacao
   *
   * @return {String} The barcode extracted from the bank slip number
   */
  barcode() {
    return this.bankSlipNumber.replace(
      /^(\d{4})(\d{5})\d{1}(\d{10})\d{1}(\d{10})\d{1}(\d{15})$/,
      '$1$5$2$3$4',
    );
  }

  /**
   * Returns the bank slip's raw number
   *
   * @return {String} The raw bank slip number
   */
  number() {
    return this.bankSlipNumber;
  }

  /**
   * Returns the bank slip number with the usual, easy-to-read mask:
   * 00000.00000 00000.000000 00000.000000 0 00000000000000
   *
   * @return {String} The formatted bank slip number
   */
  prettyNumber() {
    return this.bankSlipNumber.replace(
      /^(\d{5})(\d{5})(\d{5})(\d{6})(\d{5})(\d{6})(\d{1})(\d{14})$/,
      '$1.$2 $3.$4 $5.$6 $7 $8',
    );
  }

  /**
   * Returns the name of the bank that issued the bank slip
   *
   * This function is able to identify the most popular or commonly used banks
   * in Brazil, but not all of them are included here.
   *
   * A comprehensive list of all Brazilian banks and their codes can be found at
   * http://www.buscabanco.org.br/AgenciasBancos.asp
   *
   * @return {String} The bank name
   */
  bank() {
    switch (this.barcode().substr(0, 3)) {
      case '001': return 'Banco do Brasil';
      case '007': return 'BNDES';
      case '033': return 'Santander';
      case '069': return 'Crefisa';
      case '077': return 'Banco Inter';
      case '102': return 'XP Investimentos';
      case '104': return 'Caixa Econômica Federal';
      case '140': return 'Easynvest';
      case '197': return 'Stone';
      case '208': return 'BTG Pactual';
      case '212': return 'Banco Original';
      case '237': return 'Bradesco';
      case '260': return 'Nu Pagamentos';
      case '341': return 'Itaú';
      case '389': return 'Banco Mercantil do Brasil';
      case '422': return 'Banco Safra';
      case '505': return 'Credit Suisse';
      case '633': return 'Banco Rendimento';
      case '652': return 'Itaú Unibanco';
      case '735': return 'Banco Neon';
      case '739': return 'Banco Cetelem';
      case '745': return 'Citibank';
      default: return 'Unknown';
    }
  }

  /**
   * Returns the currency of the bank slip
   *
   * The currency is determined by the currency code, the fourth digit of the
   * barcode. A list of values other than 9 (Brazilian Real) could not be found.
   *
   * @return {String} The currency code, symbol and decimal separator
   */
  currency() {
    switch (this.barcode()[3]) {
      case '9': return { code: 'BRL', symbol: 'R$', decimal: ',' };
      default: return 'Unknown';
    }
  }

  /**
   * Returns the verification digit of the barcode
   *
   * The barcode has its own checksum digit, which is the fifth digit of itself.
   *
   * @return {String} The checksum of the barcode
   */
  checksum() {
    return this.barcode()[4];
  }

  /**
   * Returns the date when the bank slip is due
   *
   * The portion of the barcode ranging from its sixth to its nineth digits
   * represent the number of days since the 7th of October, 1997 up to when the
   * bank slip is good to be paid. Attempting to pay a bank slip after this date
   * may incurr in extra fees.
   *
   * @return {Date} The expiration date of the bank slip
   */
  expirationDate() {
    const refDate = new Date(876236400000); // 1997-10-07 12:00:00 GMT-0300
    const days = this.barcode().substr(5, 4);

    return new Date(refDate.getTime() + (days * 86400000));
  }

  /**
   * Returns the bank slip's nominal amount
   *
   * @return {String} The bank slip's raw amount
   */
  amount() {
    return (this.barcode().substr(9, 10) / 100.0).toFixed(2);
  }

  /**
   * Returns the bank slip's formatted nominal amount
   *
   * @return {String} The bank slip's formatted amount
   */
  prettyAmount() {
    const currency = this.currency();

    if (currency === 'Unknown') {
      return this.amount();
    }

    return `${currency.symbol} ${this.amount().replace('.', currency.decimal)}`;
  }

  /**
   * Renders the bank slip as a child of the provided selector
   *
   * @param {String} selector The selector to the object where the SVG must be
   * appended
   *
   * @see {@link SVG#render}
   */
  toSVG(selector) {
    const stripes = ITF.encode(this.barcode());
    return new SVG(stripes).render(selector);
  }
}

module.exports = Boleto;