feat: подписка на уведомление о поступлении товара

Co-authored-by: Cursor <cursoragent@cursor.com>

src/routes/admin.js

@@ -3,6 +3,7 @@ const { query, formatPrice } = require('../db');
 const { requireAdmin } = require('../middleware/auth');
 const { asyncHandler } = require('../utils/asyncHandler');
 const { ROLE_LABELS } = require('../constants/roles');
+const { notifyIfBackInStock } = require('../services/stock-alerts');
 
 const router = express.Router();
 
@@ -91,7 +92,9 @@ router.get(
   '/products',
   asyncHandler(async (req, res) => {
     const { rows: products } = await query(
-      `SELECT p.*, c.name AS category_name
+      `SELECT p.*, c.name AS category_name,
+              (SELECT COUNT(*)::int FROM product_stock_alerts a
+               WHERE a.product_id = p.id AND a.notified_at IS NULL) AS alert_count
        FROM products p
        LEFT JOIN categories c ON c.id = p.category_id
        ORDER BY p.id`
@@ -100,10 +103,38 @@ router.get(
       title: 'Товары',
       products,
       formatPrice,
+      stockUpdated: req.query.stock_updated === '1',
+      notified: req.query.notified ? parseInt(req.query.notified, 10) : 0,
     });
   })
 );
 
+router.post(
+  '/products/:id/stock',
+  asyncHandler(async (req, res) => {
+    const productId = parseInt(req.params.id, 10);
+    const stock = parseInt(req.body.stock, 10);
+    if (!Number.isFinite(productId) || !Number.isFinite(stock) || stock < 0) {
+      return res.redirect('/admin/products');
+    }
+
+    const { rows } = await query('SELECT stock FROM products WHERE id = $1', [productId]);
+    const oldStock = rows[0]?.stock ?? 0;
+
+    await query('UPDATE products SET stock = $1 WHERE id = $2', [stock, productId]);
+
+    let notified = 0;
+    if (oldStock <= 0 && stock > 0) {
+      const result = await notifyIfBackInStock(productId);
+      notified = result.sent;
+    }
+
+    const qs = new URLSearchParams({ stock_updated: '1' });
+    if (notified > 0) qs.set('notified', String(notified));
+    res.redirect(`/admin/products?${qs}`);
+  })
+);
+
 router.get(
   '/reservations',
   asyncHandler(async (req, res) => {

src/routes/shop.js

@@ -89,6 +89,25 @@ router.get(
 
     const errorMsg = req.query.error ? decodeURIComponent(String(req.query.error)) : null;
     const reserved = req.query.reserved === '1';
+    const notifySuccess = req.query.notify_success
+      ? decodeURIComponent(String(req.query.notify_success))
+      : null;
+    const notifyError = req.query.notify_error
+      ? decodeURIComponent(String(req.query.notify_error))
+      : null;
+
+    let stockAlertSubscribed = false;
+    let notifyEmail = res.locals.user?.email || '';
+    if (product.stock <= 0) {
+      const stockAlerts = require('../services/stock-alerts');
+      if (notifyEmail) {
+        stockAlertSubscribed = await stockAlerts.isSubscribed(
+          product.id,
+          notifyEmail,
+          req.session.userId
+        );
+      }
+    }
 
     res.render('product', {
       title: product.name,
@@ -96,6 +115,10 @@ router.get(
       userReservation,
       error: errorMsg,
       reserved,
+      notifySuccess,
+      notifyError,
+      stockAlertSubscribed,
+      notifyEmail,
     });
   })
 );

src/routes/stock-alerts.js

@@ -0,0 +1,75 @@
+const express = require('express');
+const { query, formatPrice } = require('../db');
+const { getCart, cartCount } = require('../cart');
+const { requireCookieConsent } = require('../middleware/cookieConsent');
+const { asyncHandler } = require('../utils/asyncHandler');
+const stockAlerts = require('../services/stock-alerts');
+
+const router = express.Router();
+
+router.use((req, res, next) => {
+  const cart = getCart(req);
+  res.locals.cartCount = cartCount(cart);
+  res.locals.formatPrice = formatPrice;
+  next();
+});
+
+const emailRe = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
+
+router.post(
+  '/product/:slug/notify-stock',
+  requireCookieConsent,
+  asyncHandler(async (req, res) => {
+    const slug = req.params.slug;
+    const { rows } = await query('SELECT id, name, stock FROM products WHERE slug = $1', [
+      slug,
+    ]);
+    const product = rows[0];
+
+    if (!product) {
+      return res.status(404).render('error', {
+        title: 'Не найдено',
+        message: 'Товар не найден',
+        code: 404,
+      });
+    }
+
+    if (product.stock > 0) {
+      return res.redirect(
+        `/product/${slug}?notify_error=${encodeURIComponent('Товар уже в наличии')}`
+      );
+    }
+
+    let email = (req.body.email || '').trim().toLowerCase();
+    if (req.session.userId) {
+      const { rows: users } = await query('SELECT email FROM users WHERE id = $1', [
+        req.session.userId,
+      ]);
+      if (users[0]) email = users[0].email;
+    }
+
+    if (!email || !emailRe.test(email)) {
+      return res.redirect(
+        `/product/${slug}?notify_error=${encodeURIComponent('Укажите корректный email')}`
+      );
+    }
+
+    if (await stockAlerts.isSubscribed(product.id, email, req.session.userId)) {
+      return res.redirect(
+        `/product/${slug}?notify_success=${encodeURIComponent('Вы уже подписаны — сообщим на почту')}`
+      );
+    }
+
+    await stockAlerts.subscribe({
+      productId: product.id,
+      email,
+      userId: req.session.userId || null,
+    });
+
+    res.redirect(
+      `/product/${slug}?notify_success=${encodeURIComponent('Когда товар появится, отправим письмо на ' + email)}`
+    );
+  })
+);
+
+module.exports = router;