50 lines
1.5 KiB
JavaScript
50 lines
1.5 KiB
JavaScript
const BN = require('./bn')
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const configManager = require('./new-config-manager')
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const { utils: coinUtils } = require('@lamassu/coins')
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function truncateCrypto(cryptoAtoms, cryptoCode) {
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const DECIMAL_PLACES = 6
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if (cryptoAtoms.eq(0)) return cryptoAtoms
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const scale = coinUtils.getCryptoCurrency(cryptoCode).unitScale
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const scaleFactor = BN(10).pow(scale)
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return new BN(cryptoAtoms)
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.integerValue(BN.ROUND_DOWN)
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.div(scaleFactor)
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.decimalPlaces(DECIMAL_PLACES)
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.times(scaleFactor)
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}
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function fiatToCrypto(tx, rec, deviceId, config) {
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const usableFiat = rec.fiat - rec.cashInFee
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const commissions = configManager.getCommissions(
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tx.cryptoCode,
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deviceId,
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config,
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)
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const tickerRate = new BN(tx.rawTickerPrice)
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const discount = getDiscountRate(tx.discount, commissions[tx.direction])
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const rate = tickerRate.times(discount).decimalPlaces(5)
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const unitScale = coinUtils.getCryptoCurrency(tx.cryptoCode).unitScale
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const unitScaleFactor = new BN(10).pow(unitScale)
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return truncateCrypto(
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new BN(usableFiat).div(rate.div(unitScaleFactor)),
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tx.cryptoCode,
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)
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}
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function getDiscountRate(discount, commission) {
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const bnDiscount = discount ? new BN(discount) : new BN(0)
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const bnCommission = new BN(commission)
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const percentageDiscount = new BN(1).minus(bnDiscount.div(100))
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const percentageCommission = bnCommission.div(100)
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return new BN(1).plus(percentageDiscount.times(percentageCommission))
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}
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module.exports = {
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fiatToCrypto,
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getDiscountRate,
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}
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