def update_cart(request, slug):
    if request.user.is_authenticated:
      #ok here...
    else:
        try:
            the_id = request.session["cart_id"]
        except:
            new_cart = Cart()
            product = Product.objects.get(slug=slug)
            new_cart.save()
            request.session["cart_id"] = new_cart.id
            new_cart.products.add(product)
            new_cart.save()
            return HttpResponse("<h1>okkk!</h1>")



        cart = Cart.objects.get(id = the_id)
        product = Product.objects.get(slug=slug)
        if not product in cart.products.all():
            cart.products.add(product)
            cart.save()
            return HttpResponseRedirect(reverse("cart"))
        else:
            cart.products.remove(product)
            return HttpResponseRedirect(reverse("cart"))

class Cart(models.Model):
        user = models.OneToOneField(User, on_delete="CASCADE", null=True)
        products = models.ManyToManyField(Product, blank=True)
        updated = models.DateTimeField(auto_now=True)
        timestamp = models.DateTimeField(auto_now_add=True)


        def __str__(self):
            return str(self.id)

class Product(models.Model):
    title = models.CharField(max_length=120)
    description = models.TextField(null=True, blank=True)
    price = models.DecimalField(decimal_places=2, max_digits=100, default=29.99)
    image = models.FileField(upload_to="products/images", blank=True, null=True)
    quantity = models.IntegerField(default=1)
    slug = models.SlugField(unique=True)
    timestamp = models.DateTimeField(auto_now_add=True, auto_now=False)
    updated = models.DateTimeField(auto_now_add=False, auto_now=True)
    active = models.BooleanField(default=True)

    class Meta:
        unique_together = ('title', 'slug')

    def __str__(self):
        return self.title