const express = require('express');
const svgCaptcha = require('svg-captcha');
const crypto = require('crypto');
const { query } = require('../db');

const router = express.Router();

router.get('/', async (req, res) => {
  try {
    await query("DELETE FROM captchas WHERE created_at < NOW() - INTERVAL 5 MINUTE");
    const captcha = svgCaptcha.create({
      size: 4,
      noise: 3,
      color: true,
      background: '#f4f4f4',
      width: 120,
      height: 44,
      fontSize: 40,
      ignoreChars: '0oO1iIl',
    });
    const id = crypto.randomUUID();
    await query('INSERT INTO captchas(id, question, answer) VALUES (?,?,?)', [id, '', captcha.text.toLowerCase()]);
    res.json({ id, svg: captcha.data });
  } catch (e) { res.status(500).json({ error: e.message }); }
});

async function verify(id, answer) {
  const rows = await query("SELECT * FROM captchas WHERE id = ? AND created_at > NOW() - INTERVAL 5 MINUTE", [id]);
  if (!rows.length) return false;
  await query('DELETE FROM captchas WHERE id = ?', [id]);
  return String(answer).trim().toLowerCase() === rows[0].answer;
}

module.exports = router;
module.exports.verify = verify;