lamassu-server/lib/commission-math.js
Sérgio Salgado 5045821593 fix: review
2021-01-18 19:42:03 +00:00

41 lines
1.4 KiB
JavaScript

const BN = require('./bn')
const configManager = require('./new-config-manager')
const coinUtils = require('./coin-utils')
function truncateCrypto (cryptoAtoms, cryptoCode) {
const DECIMAL_PLACES = 3
if (cryptoAtoms.eq(0)) return cryptoAtoms
const scale = 5 // TODO: change this to coins.displayScale when coins have that attribute
const scaleFactor = BN(10).pow(scale)
return BN(cryptoAtoms).truncated().div(scaleFactor)
.round(DECIMAL_PLACES).times(scaleFactor)
}
function fiatToCrypto (tx, rec, deviceId, config) {
const usableFiat = rec.fiat - rec.cashInFee
const commissions = configManager.getCommissions(tx.cryptoCode, deviceId, config)
const tickerRate = BN(tx.rawTickerPrice)
const discount = getDiscountRate(tx.discount, commissions[tx.direction])
const rate = tickerRate.mul(discount).round(5)
const unitScale = coinUtils.getCryptoCurrency(tx.cryptoCode).unitScale
const unitScaleFactor = BN(10).pow(unitScale)
return truncateCrypto(BN(usableFiat).div(rate.div(unitScaleFactor)), tx.cryptoCode)
}
function getDiscountRate (discount, commission) {
const bnDiscount = discount ? BN(discount) : BN(0)
const bnCommission = BN(commission)
const percentageDiscount = BN(1).sub(bnDiscount.div(100))
const percentageCommission = bnCommission.div(100)
return BN(1).add(percentageDiscount.mul(percentageCommission))
}
module.exports = {
truncateCrypto,
fiatToCrypto,
getDiscountRate
}