this is my model class Cart(models.Model): id = models.UUIDField(primary_key=True, default=uuid4) created_at = models.DateTimeField(auto_now_add=True) class CartItem(models.Model): cart = models.ForeignKey(Cart, on_delete=models.CASCADE, related_name=’items’) product = models.ForeignKey(Product, on_delete=models.CASCADE, related_name=’cart_items’) quantity = models.PositiveSmallIntegerField() class Meta: unique_together = [[‘cart’, ‘product’]]

this is my views

class CartItemViewSet(ModelViewSet): http_method_names = [‘get’,’post’,’patch’,’delete’] serializer_class = CartItemSerializer queryset = CartItem.objects.all() def get_queryset(self): cart_pk = self.kwargs[‘cart_pk’] return CartItem.objects.select_related(‘product’).filter(cart_id = cart_pk).all() def get_serializer_class(self): if self.request.method == ‘POST’: return AddCartItemSerializer elif self.request.method == ‘PATCH’: return ChangeCartItemSerializer return CartItemSerializer def get_serializer_context(self): return {‘cart_pk’:self.kwargs[‘cart_pk’]} class CartViewSet(CreateModelMixin, RetrieveModelMixin, DestroyModelMixin, GenericViewSet, ): serializer_class = CartSerializer queryset = Cart.objects.prefetch_related(‘items__product’).all() lookup_value_regex = ‘[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}’

and my serializer

class ProductSerializer(serializers.ModelSerializer): title = serializers.CharField(max_length=255, source=’name’) price = serializers.DecimalField(max_digits=6, decimal_places=2,source=’unit_price’) unit_price_after_tax = serializers.SerializerMethodField() class Meta: model = Product fields = [‘id’, ‘title’, ‘price’,’category’, ‘unit_price_after_tax’, ‘inventory’, ‘description’] def create(self, validated_data): product = Product(**validated_data) product.slug = slugify(product.name) product.save() return product # def update(self, instance, validated_data): # instance.inventory = validated_data.get(‘inventory’) # instance.save() # return instance def get_unit_price_after_tax(self , product): return round(product.unit_price * Decimal(1.09), 2) def validate(self, data): if len(data[‘name’]) < 6: raise serializers.ValidationError(‘Product lentgh should be at least 6.’) return data class CartProductSerializer(serializers.ModelSerializer): class Meta: model = Product fields = [‘id’, ‘name’, ‘unit_price’] class ChangeCartItemSerializer(serializers.ModelSerializer): class Meta: model = CartItem fields = [‘quantity’] class AddCartItemSerializer(serializers.ModelSerializer): class Meta: model = CartItem fields = [‘id’, ‘product’, ‘quantity’] def create(self, validated_data): cart_id = self.context[‘cart_pk’] product = validated_data.get(‘product’) quantity=validated_data.get(‘quantity’) try: cart_item = CartItem.objects.get(cart_id=cart_id, product_id=product.id) cart_item.quantity += quantity cart_item.save() except CartItem.DoesNotExist: cart_item = CartItem.objects.create(cart_id=cart_id, **validated_data) return cart_item class CartItemSerializer(serializers.ModelSerializer): product = CartProductSerializer() item_total = serializers.SerializerMethodField() class Meta: model = CartItem fields = [‘id’, ‘product’, ‘quantity’, ‘item_total’] read_only_fields = [‘id’] def get_item_total(self, cart_item): return cart_item.quantity * cart_item.product.unit_price class CartSerializer(serializers.ModelSerializer): items = CartItemSerializer(many=True, read_only = True) total_price = serializers.SerializerMethodField() class Meta: model = Cart fields = [‘id’, ‘items’,’total_price’] read_only_fields = [‘id’, ] def get_total_price(self, cart): return sum([item.quantity * item.product.unit_price for item in cart.items.all()])

can any one help me ???????????????????????????????

i have

i try searching in internet and ask chat gpt but nothing can you help me