sbtc-bridge-lib/dist/transaction_utils.js

Library for sBTC Bridge web client and API apps

import * as secp from '@noble/secp256k1';
import * as btc from '@scure/btc-signer';
import { hex } from '@scure/base';
import * as P from 'micro-packed';
import { buildDepositPayloadOpDrop } from './payload_utils.js';
import { getNet } from './wallet_utils.js';
const concat = P.concatBytes;
const privKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
const priv = secp.utils.randomPrivateKey();
const keySetForFeeCalculation = [];
keySetForFeeCalculation.push({
    priv,
    ecdsaPub: secp.getPublicKey(priv, true),
    schnorrPub: secp.getPublicKey(priv, false)
});
/**
 * @deprecated - maybe not needed with op_drop as the users wallet calculates
 * the fees. Keep for now in case we switch back to op_return
 * @returns
 */
export function approxTxFees(network, utxos, changeAddress, payeeAddress) {
    console.log('approxTxFees change=' + changeAddress);
    console.log('approxTxFees dest=' + payeeAddress);
    const net = getNet(network);
    const tx = new btc.Transaction({ allowUnknowOutput: true, allowUnknownInputs: true, allowUnknownOutputs: true });
    // create a set of inputs corresponding to the utxo set
    if (!utxos || utxos.length === 0)
        throw new Error('No UTXOs');
    for (const utxo of utxos) {
        tx.addInput({
            txid: hex.decode(utxo.txid),
            index: utxo.vout,
            witnessUtxo: {
                amount: BigInt(600),
                script: btc.p2wpkh(secp.getPublicKey(privKey, true)).script,
            },
        });
    }
    if (tx.inputsLength === 0)
        throw new Error('No confirmed UTXOs');
    const data = buildDepositPayloadOpDrop(network, 'ST1NXBK3K5YYMD6FD41MVNP3JS1GABZ8TRVX023PT', 1000);
    tx.addOutput({ script: btc.Script.encode(['RETURN', hex.decode(data)]), amount: BigInt(0) });
    //tx.addOutput({ script: btc.OutScript.encode(btc.Address(net).decode(payeeAddress)), amount });
    tx.addOutputAddress(payeeAddress, BigInt(500), net);
    const changeAmount = Math.floor(0);
    if (changeAmount > 0)
        tx.addOutputAddress(changeAddress, BigInt(changeAmount), net);
    tx.sign(privKey);
    tx.finalize();
    return Number(tx.fee);
}