metamask-extension/ui/app/pages/swaps/swaps.util.js

import log from 'loglevel'
import BigNumber from 'bignumber.js'
import abi from 'human-standard-token-abi'
import { isValidAddress } from 'ethereumjs-util'
import { calcTokenValue, calcTokenAmount } from '../../helpers/utils/token-util'
import { constructTxParams, toPrecisionWithoutTrailingZeros } from '../../helpers/utils/util'
import { decimalToHex, getValueFromWeiHex } from '../../helpers/utils/conversions.util'
import { subtractCurrencies } from '../../helpers/utils/conversion-util'
import { formatCurrency } from '../../helpers/utils/confirm-tx.util'
import fetchWithCache from '../../helpers/utils/fetch-with-cache'

import { calcGasTotal } from '../send/send.utils'

const TOKEN_TRANSFER_LOG_TOPIC_HASH = '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef'

const CACHE_REFRESH_ONE_HOUR = 3600000

const getBaseApi = function (type) {
  switch (type) {
    case 'trade':
      return `https://api.metaswap.codefi.network/trades?`
    case 'tokens':
      return `https://api.metaswap.codefi.network/tokens`
    case 'topAssets':
      return `https://api.metaswap.codefi.network/topAssets`
    case 'featureFlag':
      return `https://api.metaswap.codefi.network/featureFlag`
    case 'aggregatorMetadata':
      return `https://api.metaswap.codefi.network/aggregatorMetadata`
    case 'feeAmount':
      return `https://api.metaswap.codefi.network/fee`
    default:
      throw new Error('getBaseApi requires an api call type')
  }
}

const validHex = (string) => Boolean(string?.match(/^0x[a-f0-9]+$/u))
const truthyString = (string) => Boolean(string?.length)
const truthyDigitString = (string) => truthyString(string) && Boolean(string.match(/^\d+$/u))

const QUOTE_VALIDATORS = [
  {
    property: 'trade',
    type: 'object',
    validator: (trade) => trade && validHex(trade.data) && isValidAddress(trade.to) && isValidAddress(trade.from) && truthyString(trade.value),
  },
  {
    property: 'approvalNeeded',
    type: 'object',
    validator: (approvalTx) => (
      approvalTx === null ||
      (
        approvalTx &&
        validHex(approvalTx.data) &&
        isValidAddress(approvalTx.to) &&
        isValidAddress(approvalTx.from)
      )
    ),
  },
  {
    property: 'sourceAmount',
    type: 'string',
    validator: truthyDigitString,
  },
  {
    property: 'destinationAmount',
    type: 'string',
    validator: truthyDigitString,
  },
  {
    property: 'sourceToken',
    type: 'string',
    validator: isValidAddress,
  },
  {
    property: 'destinationToken',
    type: 'string',
    validator: isValidAddress,
  },
  {
    property: 'aggregator',
    type: 'string',
    validator: truthyString,
  },
  {
    property: 'aggType',
    type: 'string',
    validator: truthyString,
  },
  {
    property: 'error',
    type: 'object',
    validator: (error) => error === null || typeof error === 'object',
  },
  {
    property: 'averageGas',
    type: 'number',
  },
  {
    property: 'maxGas',
    type: 'number',
  },
]

const TOKEN_VALIDATORS = [
  {
    property: 'address',
    type: 'string',
    validator: isValidAddress,
  },
  {
    property: 'symbol',
    type: 'string',
    validator: (string) => truthyString(string) && string.length <= 12,
  },
  {
    property: 'decimals',
    type: 'string|number',
    validator: (string) => Number(string) >= 0 && Number(string) <= 36,
  },
]

const TOP_ASSET_VALIDATORS = TOKEN_VALIDATORS.slice(0, 2)

const AGGREGATOR_METADATA_VALIDATORS = [
  {
    property: 'color',
    type: 'string',
    validator: (string) => Boolean(string.match(/^#[A-Fa-f0-9]+$/u)),
  },
  {
    property: 'title',
    type: 'string',
    validator: truthyString,
  },
  {
    property: 'icon',
    type: 'string',
    validator: (string) => Boolean(string.match(/^data:image/u)),
  },
]

function validateData (validators, object, urlUsed) {
  return validators.every(({ property, type, validator }) => {
    const types = type.split('|')

    const valid = types.some((_type) => typeof object[property] === _type) && (!validator || validator(object[property]))
    if (!valid) {
      log.error(`response to GET ${urlUsed} invalid for property ${property}; value was:`, object[property], '| type was: ', typeof object[property])
    }
    return valid
  })
}

export async function fetchTradesInfo ({
  slippage,
  sourceToken,
  sourceDecimals,
  destinationToken,
  value,
  fromAddress,
  exchangeList,
}) {
  const urlParams = {
    destinationToken,
    sourceToken,
    sourceAmount: calcTokenValue(value, sourceDecimals).toString(10),
    slippage,
    timeout: 10000,
    walletAddress: fromAddress,
  }

  if (exchangeList) {
    urlParams.exchangeList = exchangeList
  }

  const queryString = new URLSearchParams(urlParams).toString()
  const tradeURL = `${getBaseApi('trade')}${queryString}`
  const tradesResponse = await fetchWithCache(tradeURL, { method: 'GET' }, { cacheRefreshTime: 0, timeout: 15000 })
  const newQuotes = tradesResponse.reduce((aggIdTradeMap, quote) => {
    if (quote.trade && !quote.error && validateData(QUOTE_VALIDATORS, quote, tradeURL)) {
      const constructedTrade = constructTxParams({
        to: quote.trade.to,
        from: quote.trade.from,
        data: quote.trade.data,
        amount: decimalToHex(quote.trade.value),
        gas: decimalToHex(quote.maxGas),
      })

      let { approvalNeeded } = quote

      if (approvalNeeded) {
        approvalNeeded = constructTxParams({
          ...approvalNeeded,
        })
      }

      return {
        ...aggIdTradeMap,
        [quote.aggregator]: {
          ...quote,
          slippage,
          trade: constructedTrade,
          approvalNeeded,
        },
      }
    }
    return aggIdTradeMap
  }, {})

  return newQuotes
}

export async function fetchTokens () {
  const tokenUrl = getBaseApi('tokens')
  const tokens = await fetchWithCache(tokenUrl, { method: 'GET' }, { cacheRefreshTime: CACHE_REFRESH_ONE_HOUR })
  const filteredTokens = tokens.filter((token) => validateData(TOKEN_VALIDATORS, token, tokenUrl))
  return filteredTokens
}

export async function fetchAggregatorMetadata () {
  const aggregatorMetadataUrl = getBaseApi('aggregatorMetadata')
  const aggregators = await fetchWithCache(aggregatorMetadataUrl, { method: 'GET' }, { cacheRefreshTime: CACHE_REFRESH_ONE_HOUR })
  const filteredAggregators = {}
  for (const aggKey in aggregators) {
    if (validateData(AGGREGATOR_METADATA_VALIDATORS, aggregators[aggKey], aggregatorMetadataUrl)) {
      filteredAggregators[aggKey] = aggregators[aggKey]
    }
  }
  return filteredAggregators
}

export async function fetchTopAssets () {
  const topAssetsUrl = getBaseApi('topAssets')
  const response = await fetchWithCache(topAssetsUrl, { method: 'GET' }, { cacheRefreshTime: CACHE_REFRESH_ONE_HOUR })
  const topAssetsMap = response.reduce((_topAssetsMap, asset, index) => {
    if (validateData(TOP_ASSET_VALIDATORS, asset, topAssetsUrl)) {
      return { ..._topAssetsMap, [asset.address]: { index: String(index) } }
    }
    return _topAssetsMap
  }, {})
  return topAssetsMap
}

export async function fetchSwapsFeatureLiveness () {
  const status = await fetchWithCache(getBaseApi('featureFlag'), { method: 'GET' }, { cacheRefreshTime: 600000 })
  return status?.active
}

export async function fetchMetaMaskFeeAmount () {
  const response = await fetchWithCache(getBaseApi('feeAmount'), { method: 'GET' }, { cacheRefreshTime: 600000 })
  return response?.fee
}

export async function fetchTokenPrice (address) {
  const query = `contract_addresses=${address}&vs_currencies=eth`

  const prices = await fetchWithCache(`https://api.coingecko.com/api/v3/simple/token_price/ethereum?${query}`, { method: 'GET' }, { cacheRefreshTime: 60000 })
  return prices && prices[address]?.eth
}

export async function fetchTokenBalance (address, userAddress) {
  const tokenContract = global.eth.contract(abi).at(address)
  const tokenBalancePromise = tokenContract
    ? tokenContract.balanceOf(userAddress)
    : Promise.resolve()
  const usersToken = await tokenBalancePromise
  return usersToken
}

export function getRenderableGasFeesForQuote (tradeGas, approveGas, gasPrice, currentCurrency, conversionRate) {
  const totalGasLimitForCalculation = (new BigNumber(tradeGas || '0x0', 16)).plus(approveGas || '0x0', 16).toString(16)
  const gasTotalInWeiHex = calcGasTotal(totalGasLimitForCalculation, gasPrice)

  const ethFee = getValueFromWeiHex({
    value: gasTotalInWeiHex,
    toDenomination: 'ETH',
    numberOfDecimals: 6,
  })
  const rawNetworkFees = getValueFromWeiHex({
    value: gasTotalInWeiHex,
    toCurrency: currentCurrency,
    conversionRate,
    numberOfDecimals: 2,
  })
  const formattedNetworkFee = formatCurrency(rawNetworkFees, currentCurrency)
  return {
    rawNetworkFees,
    rawEthFee: ethFee,
    feeInFiat: formattedNetworkFee,
    feeInEth: `${ethFee} ETH`,
  }
}

export function quotesToRenderableData (quotes, gasPrice, conversionRate, currentCurrency, approveGas, tokenConversionRates, customGasLimit) {
  return Object.values(quotes).map((quote) => {
    const { destinationAmount = 0, sourceAmount = 0, sourceTokenInfo, destinationTokenInfo, slippage, aggType, aggregator, gasEstimateWithRefund, averageGas } = quote
    const sourceValue = calcTokenAmount(sourceAmount, sourceTokenInfo.decimals || 18).toString(10)
    const destinationValue = calcTokenAmount(destinationAmount, destinationTokenInfo.decimals || 18).toPrecision(8)

    const {
      feeInFiat,
      rawNetworkFees,
      rawEthFee,
      feeInEth,
    } = getRenderableGasFeesForQuote(
      (
        customGasLimit ||
        gasEstimateWithRefund ||
        decimalToHex(averageGas || 800000)
      ),
      approveGas,
      gasPrice,
      currentCurrency,
      conversionRate,
    )

    const metaMaskFee = `0.875%`
    const slippageMultiplier = (new BigNumber(100 - slippage)).div(100)
    const minimumAmountReceived = (new BigNumber(destinationValue)).times(slippageMultiplier).toFixed(6)

    const tokenConversionRate = tokenConversionRates[destinationTokenInfo.address]
    const ethValueOfTrade = destinationTokenInfo.symbol === 'ETH'
      ? calcTokenAmount(destinationAmount, destinationTokenInfo.decimals || 18).minus(rawEthFee, 10)
      : (new BigNumber(tokenConversionRate || 0, 10))
        .times(calcTokenAmount(destinationAmount, destinationTokenInfo.decimals || 18), 10)
        .minus(rawEthFee, 10)

    let liquiditySourceKey
    let renderedSlippage = slippage

    if (aggType === 'AGG') {
      liquiditySourceKey = 'swapAggregator'
    } else if (aggType === 'RFQ') {
      liquiditySourceKey = 'swapRequestForQuotation'
      renderedSlippage = 0
    } else if (aggType === 'DEX') {
      liquiditySourceKey = 'swapDecentralizedExchange'
    } else {
      liquiditySourceKey = 'swapUnknown'
    }

    return {
      aggId: aggregator,
      amountReceiving: `${destinationValue} ${destinationTokenInfo.symbol}`,
      destinationTokenDecimals: destinationTokenInfo.decimals,
      destinationTokenSymbol: destinationTokenInfo.symbol,
      destinationTokenValue: formatSwapsValueForDisplay(destinationValue),
      isBestQuote: quote.isBestQuote,
      liquiditySourceKey,
      metaMaskFee,
      feeInEth,
      detailedNetworkFees: `${feeInEth} (${feeInFiat})`,
      networkFees: feeInFiat,
      quoteSource: aggType,
      rawNetworkFees,
      slippage: renderedSlippage,
      sourceTokenDecimals: sourceTokenInfo.decimals,
      sourceTokenSymbol: sourceTokenInfo.symbol,
      sourceTokenValue: sourceValue,
      ethValueOfTrade,
      minimumAmountReceived,
    }
  })
}

export function getSwapsTokensReceivedFromTxMeta (tokenSymbol, txMeta, tokenAddress, accountAddress, tokenDecimals, approvalTxMeta) {
  const txReceipt = txMeta?.txReceipt
  if (tokenSymbol === 'ETH') {
    if (!txReceipt || !txMeta || !txMeta.postTxBalance || !txMeta.preTxBalance) {
      return null
    }

    let approvalTxGasCost = '0x0'
    if (approvalTxMeta && approvalTxMeta.txReceipt) {
      approvalTxGasCost = calcGasTotal(approvalTxMeta.txReceipt.gasUsed, approvalTxMeta.txParams.gasPrice)
    }

    const gasCost = calcGasTotal(txReceipt.gasUsed, txMeta.txParams.gasPrice)
    const totalGasCost = (new BigNumber(gasCost, 16)).plus(approvalTxGasCost, 16).toString(16)

    const preTxBalanceLessGasCost = subtractCurrencies(txMeta.preTxBalance, totalGasCost, {
      aBase: 16,
      bBase: 16,
      toNumericBase: 'hex',
    })

    const ethReceived = subtractCurrencies(txMeta.postTxBalance, preTxBalanceLessGasCost, {
      aBase: 16,
      bBase: 16,
      fromDenomination: 'WEI',
      toDenomination: 'ETH',
      toNumericBase: 'dec',
      numberOfDecimals: 6,
    })
    return ethReceived
  }
  const txReceiptLogs = txReceipt?.logs
  if (txReceiptLogs && txReceipt?.status !== '0x0') {
    const tokenTransferLog = txReceiptLogs.find((txReceiptLog) => {
      const isTokenTransfer = txReceiptLog.topics && txReceiptLog.topics[0] === TOKEN_TRANSFER_LOG_TOPIC_HASH
      const isTransferFromGivenToken = txReceiptLog.address === tokenAddress
      const isTransferFromGivenAddress = txReceiptLog.topics && txReceiptLog.topics[2] && txReceiptLog.topics[2].match(accountAddress.slice(2))
      return isTokenTransfer && isTransferFromGivenToken && isTransferFromGivenAddress
    })
    return tokenTransferLog
      ? toPrecisionWithoutTrailingZeros(
        calcTokenAmount(tokenTransferLog.data, tokenDecimals).toString(10), 6,
      )
      : ''
  }
  return null
}

export function formatSwapsValueForDisplay (destinationAmount) {
  let amountToDisplay = toPrecisionWithoutTrailingZeros(destinationAmount, 12)
  if (amountToDisplay.match(/e[+-]/u)) {
    amountToDisplay = (new BigNumber(amountToDisplay)).toFixed()
  }
  return amountToDisplay
}