eth.js

/* eslint-disable no-param-reassign */
/**
 * @author JeffVader
 */

const axios = require('axios');
const path = require('path');
const fs = require('fs');

const INFURA_KEY = '2bf416022d924fdcabe3b279f3ac9b90';

function writeToFileSync(filepath, args) {
  const flag = 'w';
  const fd = fs.openSync(filepath, flag);
  fs.writeSync(fd, args);
  fs.closeSync(fd);
}

async function getRPCResponse(method, params) {
  const url = `https://mainnet.infura.io/v3/${INFURA_KEY}`;
  params = params || [];
  const data = {
    jsonrpc: '2.0',
    method,
    params,
    id: 1,
  };
  const headers = {
    'Content-Type': 'application/json',
  };
  const response = await axios.post(url, data, headers);
  return response.data.result;
}

async function getContractTransfers(contract, fromBlock, toBlock) {
  const transferHash = '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef';
  const params = [{
    address: contract,
    fromBlock,
    toBlock,
    topics: [transferHash],
  }];
  // Warning: eth_getLogs will fail if there are more than 10,000 records.
  // - at that point we will need to move to a paging approach.
  const logs = await getRPCResponse('eth_getLogs', params);
  logs.forEach((log) => {
    // eslint-disable-next-line radix
    log.amount = Number.parseInt(log.data);
    log.from = log.topics[1].substring(0, 2) + log.topics[1].substring(26);
    log.to = log.topics[2].substring(0, 2) + log.topics[2].substring(26);
  });
  return logs;
}

function getBalanceList(transfers) {
  const balances = {};
  transfers.forEach((transfer) => {
    if (transfer.from !== transfer.to) {
      let from = balances[transfer.from] || 0;
      let to = balances[transfer.to] || 0;
      from -= transfer.amount;
      to += transfer.amount;
      balances[transfer.from] = from;
      balances[transfer.to] = to;
    }
  });
  const sortedBalances = [];
  // eslint-disable-next-line no-restricted-syntax, prefer-const
  for (let address in balances) {
    if (balances[address] > 0) {
      sortedBalances.push({ address, balance: balances[address] });
    }
  }
  sortedBalances.sort((a, b) => b.balance - a.balance);
  return sortedBalances;
}

async function start(contract) {
  const blockNum = await getRPCResponse('eth_blockNumber');
  const transfers = await getContractTransfers(contract, '0x0', blockNum);
  const balances = await getBalanceList(transfers);

  let total = 0;
  balances.forEach((balance) => {
    total += Number(balance.balance / (10 ** 8));
  });

  const homeDirPath = path.join(__dirname, './export/');
  const filepath = `${homeDirPath}ethlist.json`;
  console.log(`Done Eth - ${balances.length} records found. Exported at ${filepath}. Total Flux-ETH: ${total.toLocaleString()} (${total}).`);
  writeToFileSync(filepath, JSON.stringify(balances, null, 2));
}

module.exports = { start };