divvy-lib-orderbook/dist/npm/currencyutils.js

Convenient Orderbook class.

'use strict'; // eslint-disable-line strict
var _ = require('lodash');

function isISOCode(currency) {
  return (/^[A-Z0-9]{3}$/.test(currency)
  );
}

function isHexCurrency(currency) {
  return (/[A-Fa-f0-9]{40}/.test(currency)
  );
}

function getISOCode(hexCurrency) {
  var bytes = new Buffer(hexCurrency, 'hex');
  if (_.every(bytes, function (octet) {
    return octet === 0;
  })) {
    return 'XDV';
  }
  if (!_.every(bytes, function (octet, i) {
    return octet === 0 || i >= 12 && i <= 14;
  })) {
    return null;
  }
  var code = String.fromCharCode(bytes[12]) + String.fromCharCode(bytes[13]) + String.fromCharCode(bytes[14]);
  return isISOCode(code) ? code : null;
}

function normalizeCurrency(currency) {
  if (isISOCode(currency.toUpperCase())) {
    return currency.toUpperCase();
  } else if (isHexCurrency(currency)) {
    var code = getISOCode(currency);
    return code === null ? currency.toUpperCase() : code;
  }
  throw new Error('invalid currency');
}

function toHexCurrency(currency) {
  if (isISOCode(currency)) {
    var bytes = new Buffer(20);
    bytes.fill(0);
    if (currency !== 'XDV') {
      bytes[12] = currency.charCodeAt(0);
      bytes[13] = currency.charCodeAt(1);
      bytes[14] = currency.charCodeAt(2);
    }
    return bytes.toString('hex').toUpperCase();
  } else if (isHexCurrency(currency)) {
    return currency.toUpperCase();
  }
  throw new Error('invalid currency');
}

function isValidCurrency(currency) {
  return isISOCode(currency.toUpperCase()) || isHexCurrency(currency);
}

exports.normalizeCurrency = normalizeCurrency;
exports.isValidCurrency = isValidCurrency;
exports.toHexCurrency = toHexCurrency;