feat: MC Report System - MySQL + Express + Vanilla JS SPA

backend/routes/captcha.js

@@ -0,0 +1,31 @@
+const express = require('express');
+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 id = crypto.randomUUID();
+    const ops = ['+', '-', '\u00d7'];
+    const op = ops[Math.floor(Math.random() * ops.length)];
+    let a, b;
+    if (op === '\u00d7') { a = Math.floor(Math.random() * 9) + 1; b = Math.floor(Math.random() * 9) + 1; }
+    else { a = Math.floor(Math.random() * 20) + 1; b = Math.floor(Math.random() * 10) + 1; if (op === '-' && a < b) [a, b] = [b, a]; }
+    const answer = op === '+' ? a + b : op === '-' ? a - b : a * b;
+    const question = `${a} ${op} ${b} = ?`;
+    await query('INSERT INTO captchas(id, question, answer) VALUES (?,?,?)', [id, question, String(answer)]);
+    res.json({ id, question });
+  } 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() === rows[0].answer;
+}
+
+module.exports = router;
+module.exports.verify = verify;