alerts.js

const rp = require("request-promise");

const EXCHANGES = require("./config/exchanges.json");
const API = "https://api.semux.info/v2.3.0/";
const TX_VALUE = 2500; // SEM
let BEST_HEIGHT = 0;

async function scanNewBlock() {
  let lastHeight;
  try {
    lastHeight = JSON.parse(await rp(`${API}latest-block-number`));
  } catch (e) {
    console.error("Failed to get latest block number", e.message);
    return { error: true };
  }
  lastHeight = parseInt(lastHeight.result, 10);
  if (lastHeight === BEST_HEIGHT) {
    return { error: true };
  }
  BEST_HEIGHT = lastHeight;
  let block;
  try {
    block = JSON.parse(await rp(`${API}block-by-number?number=${BEST_HEIGHT}`));
  } catch (e) {
    console.error("Failed to get block by number", e.message);
    return { error: true };
  }
  if (!block.result || !block.result.transactions) {
    return { error: true };
  }
  let transfers = [];
  for (let tx of block.result.transactions) {
    let value = parseInt(tx.value, 10) / 1e9;
    if (tx.type !== "TRANSFER" || value < TX_VALUE) {
      continue;
    }
    if (EXCHANGES[tx.from]) {
      transfers.push({
        exchange: EXCHANGES[tx.from],
        value: value.toFixed(2),
        type: "withdrawn",
      });
    }
    if (EXCHANGES[tx.to]) {
      transfers.push({
        exchange: EXCHANGES[tx.to],
        value: value.toFixed(2),
        type: "deposited",
      });
    }
  }
  return { success: true, transfers: transfers };
}

module.exports = {
  scanNewBlock,
};