1 files changed, 118 insertions, 0 deletions
diff --git a/ui/app/helpers/utils/token-util.js b/ui/app/helpers/utils/token-util.js
new file mode 100644
index 000000000..35a19a69f
--- /dev/null
+++ b/ui/app/helpers/utils/token-util.js
@@ -0,0 +1,118 @@
+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)
+}
+
+export function getTokenValue (tokenParams = []) {
+  const valueData = tokenParams.find(param => param.name === '_value')
+  return valueData && valueData.value
+}