feat: enable color selection for cart items and enhance UI integration

- Added `selected_color` field to `CartItem` model with migration
- Updated color swatch behavior on product detail page with selection logic and disabled button handling
- Improved cart templates to display selected color alongside item details
- Modified `add_item_to_cart` service and `add` view to handle color selection
- Enhanced styles for active swatches and cart item color display

orders/migrations/0003_cartitem_selected_color.py

@@ -0,0 +1,20 @@
+# Generated by Django 6.0.5 on 2026-05-25 22:37
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('items', '0005_remove_item_color_item_colors'),
+        ('orders', '0002_order_orderitem'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='cartitem',
+            name='selected_color',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='items.color', verbose_name='Выбранный цвет'),
+        ),
+    ]

orders/models.py

@@ -36,6 +36,12 @@ class CartItem(models.Model):
         related_name="cart_entries",
         verbose_name="Товар",
     )
+    selected_color = models.ForeignKey(
+        'items.Color',
+        on_delete=models.SET_NULL,
+        null=True, blank=True,
+        verbose_name='Выбранный цвет',
+    )
     quantity = models.PositiveIntegerField(
         validators=[MinValueValidator(1)],
         verbose_name="Количество",

orders/services.py

@@ -72,11 +72,13 @@ def get_user_cart_items(user: Any) -> list[CartItem]:
         return []
 
     return list(
-        cart.items.select_related("item__category", "item__subcategory").prefetch_related("item__images")
+        cart.items
+        .select_related("item__category", "item__subcategory", "selected_color")
+        .prefetch_related("item__images")
     )
 
 
-def add_item_to_cart(user: Any, item: Item, quantity: int = 1) -> tuple[CartItem, bool]:
+def add_item_to_cart(user: Any, item: Item, quantity: int = 1, color=None) -> tuple[CartItem, bool]:
     if quantity < 1:
         raise ValidationError("Количество товара должно быть не меньше 1.")
 
@@ -87,8 +89,11 @@ def add_item_to_cart(user: Any, item: Item, quantity: int = 1) -> tuple[CartItem
     cart_item, created = CartItem.objects.get_or_create(
         cart=cart,
         item=item,
-        defaults={"quantity": quantity},
+        defaults={"quantity": quantity, "selected_color": color},
     )
+    if not created and cart_item.selected_color_id != (color.pk if color else None):
+        cart_item.selected_color = color
+        cart_item.save(update_fields=["selected_color", "updated_at"])
     return cart_item, created
 
 

orders/views.py

@@ -7,7 +7,7 @@ from django.urls import reverse
 from django.utils.http import url_has_allowed_host_and_scheme
 from django.views.decorators.http import require_POST
 
-from items.models import Item
+from items.models import Color, Item
 from orders.forms import CheckoutForm
 from orders.models import CartItem, Order
 from orders.services import (
@@ -112,8 +112,16 @@ def success(request: HttpRequest, order_id: int) -> HttpResponse:
 def add(request: HttpRequest) -> HttpResponse:
     item = get_object_or_404(Item, pk=request.POST.get("item_id"))
 
+    color_id = request.POST.get("color_id")
+    color = None
+    if color_id:
+        try:
+            color = Color.objects.get(pk=color_id)
+        except Color.DoesNotExist:
+            pass
+
     try:
-        _, created = add_item_to_cart(request.user, item)
+        _, created = add_item_to_cart(request.user, item, color=color)
         if created:
             messages.success(request, f"Товар «{item.name}» добавлен в корзину.")
         else: