sendCoins.js

const { Users } = require("./models");
const rp = require("request-promise");
const Long = require("long");

const { toHexString, parseBal, hexBytes } = require("./utils.js");
const { Network, TransactionType, Transaction, Key } = require("semux-js");
const { faucetAddress, faucetPR } = require("./config/config-bot.json");

const API = "https://api.semux.info/v2.1.0/";
const FEE = 5000000;

async function getAddress(address) {
  return JSON.parse(await rp(API + "account?address=" + address));
}

async function sendCoins(authorId, toAddress, value, msg, comment) {
  let hexString = "0x746970"; // default "tip"
  if (comment) {
    let bytesArray = Buffer.from(comment);
    hexString = "0x" + toHexString(bytesArray);
  }
  if (!toAddress || !value) {
    return {
      error: true,
      reason: "Amount of SEM and Discord Username are required.",
    };
  }
  let from = "";
  if (authorId) {
    from = await Users.findOne({ where: { discord_id: authorId } });
    if (!from) {
      return {
        error: true,
        reason: "You don't have account yet, type /getAddress first.",
      };
    }
  } else {
    from = {
      address: faucetAddress,
      private_key: faucetPR,
    };
  }
  var isFrom = await getAddress(from.address);
  try {
    await getAddress(toAddress);
  } catch (e) {
    return { error: true, reason: "Wrong recipient, try another one." };
  }

  if (value.includes(",")) value = value.replace(/,/g, ".");
  let amount = parseFloat(value);
  if (!amount) return { error: true, reason: "Amount is not correct." };
  amount = amount * Math.pow(10, 9);
  if (amount < 0.000000001)
    return { error: true, reason: "Wrong amount, try another one." };
  // check reciever balance before transfer
  const fromAddressBal = await getAddress(from.address);
  let nonce =
    parseInt(isFrom.result.nonce, 10) +
    parseInt(isFrom.result.pendingTransactionCount, 10);
  const available = parseFloat(fromAddressBal.result.available);
  if (available === amount) {
    amount = amount - FEE;
  }
  if (available < amount + FEE) {
    return {
      error: true,
      reason: `Insufficient balance, you have **${parseBal(available)} SEM**`,
    };
  }
  const privateKey = Key.importEncodedPrivateKey(hexBytes(from.private_key));
  try {
    var tx = new Transaction(
      Network.MAINNET,
      TransactionType.TRANSFER,
      hexBytes(toAddress), // to
      Long.fromNumber(amount), // value
      Long.fromNumber(FEE), // fee
      Long.fromNumber(nonce), // nonce
      Long.fromNumber(new Date().getTime()), // timestamp
      hexBytes(hexString) // data
    ).sign(privateKey);
  } catch (e) {
    console.log(e);
  }
  let hash = await sendToApi(tx);

  if (!hash) {
    return { error: true, reason: "Error while tried to create transaction." };
  } else {
    return { error: false, hash };
  }
}

async function sendToApi(tx) {
  const serialize = Buffer.from(tx.toBytes().buffer).toString("hex");
  try {
    var { result } = await rp({
      method: "POST",
      uri: `${API}transaction/raw?raw=${serialize}&validateNonce=true`,
      json: true,
    });
  } catch (e) {
    console.log(e);
  }
  if (result) {
    return result;
  }
}

module.exports = sendCoins;