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const log = require('loglevel')
const util = require('./util')
const BigNumber = require('bignumber.js')
import contractMap from 'eth-contract-metadata'
const casedContractMap = Object.keys(contractMap).reduce((acc, base) => {
return {
...acc,
[base.toLowerCase()]: contractMap[base],
}
}, {})
const DEFAULT_SYMBOL = ''
const DEFAULT_DECIMALS = '0'
async function getSymbolFromContract (tokenAddress) {
const token = util.getContractAtAddress(tokenAddress)
try {
const result = await token.symbol()
return result[0]
} catch (error) {
log.warn(`symbol() call for token at address ${tokenAddress} resulted in error:`, error)
}
}
async function getDecimalsFromContract (tokenAddress) {
const token = util.getContractAtAddress(tokenAddress)
try {
const result = await token.decimals()
const decimalsBN = result[0]
return decimalsBN && decimalsBN.toString()
} catch (error) {
log.warn(`decimals() call for token at address ${tokenAddress} resulted in error:`, error)
}
}
function getContractMetadata (tokenAddress) {
return tokenAddress && casedContractMap[tokenAddress.toLowerCase()]
}
async function getSymbol (tokenAddress) {
let symbol = await getSymbolFromContract(tokenAddress)
if (!symbol) {
const contractMetadataInfo = getContractMetadata(tokenAddress)
if (contractMetadataInfo) {
symbol = contractMetadataInfo.symbol
}
}
return symbol
}
async function getDecimals (tokenAddress) {
let decimals = await getDecimalsFromContract(tokenAddress)
if (!decimals || decimals === '0') {
const contractMetadataInfo = getContractMetadata(tokenAddress)
if (contractMetadataInfo) {
decimals = contractMetadataInfo.decimals
}
}
return decimals
}
export async function getSymbolAndDecimals (tokenAddress, existingTokens = []) {
const existingToken = existingTokens.find(({ address }) => tokenAddress === address)
if (existingToken) {
return {
symbol: existingToken.symbol,
decimals: existingToken.decimals,
}
}
let symbol, decimals
try {
symbol = await getSymbol(tokenAddress)
decimals = await getDecimals(tokenAddress)
} catch (error) {
log.warn(`symbol() and decimal() calls for token at address ${tokenAddress} resulted in error:`, error)
}
return {
symbol: symbol || DEFAULT_SYMBOL,
decimals: decimals || DEFAULT_DECIMALS,
}
}
export function tokenInfoGetter () {
const tokens = {}
return async (address) => {
if (tokens[address]) {
return tokens[address]
}
tokens[address] = await getSymbolAndDecimals(address)
return tokens[address]
}
}
export function calcTokenAmount (value, decimals) {
const multiplier = Math.pow(10, Number(decimals || 0))
return new BigNumber(String(value)).div(multiplier).toNumber()
}
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