const { addCurrencies, conversionUtil, conversionGTE, multiplyCurrencies, conversionGreaterThan, } = require('../../conversion-util') const { calcTokenAmount, } = require('../../token-util') const { INSUFFICIENT_FUNDS_ERROR, INSUFFICIENT_TOKENS_ERROR, NEGATIVE_ETH_ERROR, ONE_GWEI_IN_WEI_HEX, SIMPLE_GAS_COST, TOKEN_TRANSFER_FUNCTION_SIGNATURE, } = require('./send.constants') const abi = require('ethereumjs-abi') const ethUtil = require('ethereumjs-util') module.exports = { calcGasTotal, calcTokenBalance, doesAmountErrorRequireUpdate, estimateGas, estimateGasPriceFromRecentBlocks, generateTokenTransferData, getAmountErrorObject, isBalanceSufficient, isTokenBalanceSufficient, } function calcGasTotal (gasLimit, gasPrice) { return multiplyCurrencies(gasLimit, gasPrice, { toNumericBase: 'hex', multiplicandBase: 16, multiplierBase: 16, }) } function isBalanceSufficient ({ amount = '0x0', amountConversionRate = 0, balance, conversionRate, gasTotal = '0x0', primaryCurrency, }) { const totalAmount = addCurrencies(amount, gasTotal, { aBase: 16, bBase: 16, toNumericBase: 'hex', }) const balanceIsSufficient = conversionGTE( { value: balance, fromNumericBase: 'hex', fromCurrency: primaryCurrency, conversionRate, }, { value: totalAmount, fromNumericBase: 'hex', conversionRate: Number(amountConversionRate) || conversionRate, fromCurrency: primaryCurrency, }, ) return balanceIsSufficient } function isTokenBalanceSufficient ({ amount = '0x0', tokenBalance, decimals, }) { const amountInDec = conversionUtil(amount, { fromNumericBase: 'hex', }) const tokenBalanceIsSufficient = conversionGTE( { value: tokenBalance, fromNumericBase: 'dec', }, { value: calcTokenAmount(amountInDec, decimals), fromNumericBase: 'dec', }, ) return tokenBalanceIsSufficient } function getAmountErrorObject ({ amount, amountConversionRate, balance, conversionRate, gasTotal, primaryCurrency, selectedToken, tokenBalance, }) { let insufficientFunds = false if (gasTotal && conversionRate) { insufficientFunds = !isBalanceSufficient({ amount: selectedToken ? '0x0' : amount, amountConversionRate, balance, conversionRate, gasTotal, primaryCurrency, }) } let inSufficientTokens = false if (selectedToken && tokenBalance !== null) { const { decimals } = selectedToken inSufficientTokens = !isTokenBalanceSufficient({ tokenBalance, amount, decimals, }) } const amountLessThanZero = conversionGreaterThan( { value: 0, fromNumericBase: 'dec' }, { value: amount, fromNumericBase: 'hex' }, ) let amountError = null if (insufficientFunds) { amountError = INSUFFICIENT_FUNDS_ERROR } else if (inSufficientTokens) { amountError = INSUFFICIENT_TOKENS_ERROR } else if (amountLessThanZero) { amountError = NEGATIVE_ETH_ERROR } return { amount: amountError } } function calcTokenBalance ({ selectedToken, usersToken }) { const { decimals } = selectedToken || {} return calcTokenAmount(usersToken.balance.toString(), decimals) + '' } function doesAmountErrorRequireUpdate ({ balance, gasTotal, prevBalance, prevGasTotal, prevTokenBalance, selectedToken, tokenBalance, }) { const balanceHasChanged = balance !== prevBalance const gasTotalHasChange = gasTotal !== prevGasTotal const tokenBalanceHasChanged = selectedToken && tokenBalance !== prevTokenBalance const amountErrorRequiresUpdate = balanceHasChanged || gasTotalHasChange || tokenBalanceHasChanged return amountErrorRequiresUpdate } async function estimateGas ({ selectedAddress, selectedToken, blockGasLimit, to, value, gasPrice, estimateGasMethod }) { const paramsForGasEstimate = { from: selectedAddress, value, gasPrice } if (selectedToken) { paramsForGasEstimate.value = '0x0' paramsForGasEstimate.data = generateTokenTransferData({ toAddress: to, amount: value, selectedToken }) } // if recipient has no code, gas is 21k max: const hasRecipient = Boolean(to) let code if (hasRecipient) code = await global.eth.getCode(to) if (hasRecipient && (!code || code === '0x') && !selectedToken) { return SIMPLE_GAS_COST } paramsForGasEstimate.to = selectedToken ? selectedToken.address : to // if not, fall back to block gasLimit paramsForGasEstimate.gas = ethUtil.addHexPrefix(multiplyCurrencies(blockGasLimit, 0.95, { multiplicandBase: 16, multiplierBase: 10, roundDown: '0', toNumericBase: 'hex', })) // run tx return new Promise((resolve, reject) => { return estimateGasMethod(paramsForGasEstimate, (err, estimatedGas) => { if (err) { const simulationFailed = ( err.message.includes('Transaction execution error.') || err.message.includes('gas required exceeds allowance or always failing transaction') ) if (simulationFailed) { return resolve(paramsForGasEstimate.gas) } else { return reject(err) } } return resolve(estimatedGas.toString(16)) }) }) } function generateTokenTransferData ({ toAddress = '0x0', amount = '0x0', selectedToken }) { if (!selectedToken) return return TOKEN_TRANSFER_FUNCTION_SIGNATURE + Array.prototype.map.call( abi.rawEncode(['address', 'uint256'], [toAddress, ethUtil.addHexPrefix(amount)]), x => ('00' + x.toString(16)).slice(-2) ).join('') } function estimateGasPriceFromRecentBlocks (recentBlocks) { // Return 1 gwei if no blocks have been observed: if (!recentBlocks || recentBlocks.length === 0) { return ONE_GWEI_IN_WEI_HEX } const lowestPrices = recentBlocks.map((block) => { if (!block.gasPrices || block.gasPrices.length < 1) { return ONE_GWEI_IN_WEI_HEX } return block.gasPrices.reduce((currentLowest, next) => { return parseInt(next, 16) < parseInt(currentLowest, 16) ? next : currentLowest }) }) .sort((a, b) => parseInt(a, 16) > parseInt(b, 16) ? 1 : -1) return lowestPrices[Math.floor(lowestPrices.length / 2)] }