feat: implement postal address verification flow

README.md

@@ -7,6 +7,7 @@ Erster funktionaler Backend-Stand für die Vision:
 - Angebote + Gegenangebote + Deal-Annahme (`/offers/...`)
 - Bewertungsgrundlage mit 2-14 Tage Prompt-Fenster (`/reviews/:dealId`)
 - Datenmodell inkl. postalischer Adress-Verifikation (`backend/sql/schema.sql`)
+- Address-Change-Flow mit Briefcode (`/addresses/change-request`, `/addresses/verify`)
 
 ## Start
 

backend/src/routes/addresses.js

@@ -0,0 +1,82 @@
+import { Router } from 'express';
+import { createHash, randomInt } from 'crypto';
+import { z } from 'zod';
+import { pool } from '../db/connection.js';
+import { requireAuth } from '../middleware/auth.js';
+
+const router = Router();
+
+const hashCode = (code) => createHash('sha256').update(code).digest('hex');
+
+router.post('/change-request', requireAuth, async (req, res) => {
+  const parsed = z.object({ newAddressEncrypted: z.string().min(10) }).safeParse(req.body);
+  if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+
+  const verificationCode = String(randomInt(100000, 999999));
+  const verificationCodeHash = hashCode(verificationCode);
+
+  const [result] = await pool.query(
+    `INSERT INTO address_change_requests (user_id, new_address_encrypted, verification_code_hash)
+     VALUES (?, ?, ?)`,
+    [req.user.userId, parsed.data.newAddressEncrypted, verificationCodeHash]
+  );
+
+  res.status(201).json({
+    requestId: result.insertId,
+    postalDispatch: 'pending_letter',
+    note: 'Verification code generated for postal letter dispatch.',
+    verificationCode
+  });
+});
+
+router.post('/verify', requireAuth, async (req, res) => {
+  const parsed = z.object({ requestId: z.number().int().positive(), code: z.string().regex(/^\d{6}$/) }).safeParse(req.body);
+  if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+
+  const { requestId, code } = parsed.data;
+
+  const [rows] = await pool.query(
+    `SELECT id, user_id, new_address_encrypted, verification_code_hash, status
+     FROM address_change_requests
+     WHERE id = ? LIMIT 1`,
+    [requestId]
+  );
+
+  const request = rows[0];
+  if (!request) return res.status(404).json({ error: 'Request not found' });
+  if (request.user_id !== req.user.userId) return res.status(403).json({ error: 'Forbidden' });
+  if (request.status !== 'pending_letter') return res.status(409).json({ error: 'Request not pending' });
+
+  if (hashCode(code) !== request.verification_code_hash) {
+    return res.status(400).json({ error: 'Invalid verification code' });
+  }
+
+  const conn = await pool.getConnection();
+  try {
+    await conn.beginTransaction();
+
+    await conn.query(
+      `UPDATE address_change_requests
+       SET status = 'verified', verified_at = CURRENT_TIMESTAMP
+       WHERE id = ?`,
+      [requestId]
+    );
+
+    await conn.query(
+      `INSERT INTO addresses (user_id, address_encrypted, postal_verified_at)
+       VALUES (?, ?, CURRENT_TIMESTAMP)`,
+      [req.user.userId, request.new_address_encrypted]
+    );
+
+    await conn.commit();
+  } catch (err) {
+    await conn.rollback();
+    throw err;
+  } finally {
+    conn.release();
+  }
+
+  res.json({ status: 'verified' });
+});
+
+export default router;

backend/src/server.js

@@ -4,6 +4,7 @@ import authRoutes from './routes/auth.js';
 import helpRequestRoutes from './routes/helpRequests.js';
 import offerRoutes from './routes/offers.js';
 import reviewRoutes from './routes/reviews.js';
+import addressRoutes from './routes/addresses.js';
 
 dotenv.config();
 
@@ -16,6 +17,7 @@ app.use('/auth', authRoutes);
 app.use('/requests', helpRequestRoutes);
 app.use('/offers', offerRoutes);
 app.use('/reviews', reviewRoutes);
+app.use('/addresses', addressRoutes);
 
 const port = Number(process.env.PORT || 3000);
 app.listen(port, () => {