lamassu-server/lib/plugins/ticker/itbit/itbit.js

const axios = require('axios')
const _ = require('lodash/fp')

const BN = require('../../../bn')
const common = require('../../common/itbit')

exports.NAME = 'itBit'
exports.SUPPORTED_MODULES = ['ticker']

function findCurrency (fxRates, fiatCode) {
  const rates = _.find(_.matchesProperty('code', fiatCode), fxRates)
  if (!rates || !rates.rate) throw new Error(`Unsupported currency: ${fiatCode}`)
  return BN(rates.rate)
}

exports.ticker = function ticker (account, fiatCode, cryptoCode) {
  if (_.includes(fiatCode, ['USD', 'EUR', 'SGD'])) {
    return getCurrencyRates(fiatCode, cryptoCode)
  }

  return axios.get('https://bitpay.com/api/rates')
    .then(response => {
      const fxRates = response.data
      try {
        const usdRate = findCurrency(fxRates, 'USD')
        const fxRate = findCurrency(fxRates, fiatCode).div(usdRate)

        return getCurrencyRates('USD', cryptoCode)
          .then(res => ({
            rates: {
              ask: res.rates.ask.times(fxRate),
              bid: res.rates.bid.times(fxRate)
            }
          }))
      } catch (e) {
        return Promise.reject(e)
      }
    })
}

function getCurrencyRates (fiatCode, cryptoCode) {
  try {
    const market = common.buildMarket(fiatCode, cryptoCode)
    return common.request('GET', '/markets/' + market + '/ticker')
      .then(r => ({
        rates: {
          ask: BN(r.ask),
          bid: BN(r.bid)
        }
      }))
  } catch (e) {
    return Promise.reject(e)
  }
}