/**
 * tron-sim-transfer.mjs — simulate USDT.transfer with caller = the HTLC contract
 * (vs an EOA) to surface the real revert reason behind B2's "transfer failed".
 */
import { readFileSync } from 'node:fs';
import { join } from 'node:path';
import { TronWeb } from 'tronweb';

const ROOT = join(import.meta.dirname, '..');
const NILE = 'https://nile.trongrid.io';
const sw = JSON.parse(readFileSync(join(ROOT, '.tron-b2-lastswap.json'), 'utf8'));
const k = JSON.parse(readFileSync(join(ROOT, '.tron-nile-keys.json'), 'utf8'));
const tronWeb = new TronWeb({ fullHost: NILE, privateKey: k.privateKey });

const USDT_HEX = tronWeb.address.toHex(sw.usdt);
const decodeRevert = (hexStr) => {
  if (!hexStr) return '(no data)';
  if (hexStr.startsWith('08c379a0')) { const len = parseInt(hexStr.slice(72, 136), 16); return Buffer.from(hexStr.slice(136, 136 + len * 2), 'hex').toString('utf8'); }
  return hexStr.slice(0, 80);
};

async function sim(caller, to, value, label) {
  const res = await tronWeb.transactionBuilder.triggerConstantContract(
    USDT_HEX, 'transfer(address,uint256)', {},
    [{ type: 'address', value: tronWeb.address.toHex(to) }, { type: 'uint256', value }],
    tronWeb.address.toHex(caller));
  const okFlag = res?.result?.result === true;
  const cres = res?.constant_result?.[0];
  const msgHex = res?.result?.message ? Buffer.from(res.result.message, 'hex').toString('utf8') : '';
  console.log(`\n${label} (caller ${caller}):`);
  console.log('  result.result:', okFlag, '| code:', res?.result?.code || '-');
  console.log('  constant_result:', cres ? cres.slice(0, 80) : '(none)', '->', decodeRevert(cres));
  if (msgHex) console.log('  message:', msgHex);
}

console.log('USDT', sw.usdt, '| HTLC', sw.htlc, '| receiver', sw.receiver, '| amount', sw.amount);
await sim(sw.htlc, sw.receiver, sw.amount, '1) HTLC -> receiver (the failing call)');
await sim(k.address, sw.receiver, 100000, '2) Alice(EOA) -> receiver (control)');