from dataclasses import dataclass
from typing import Optional


@dataclass(frozen=True)
class CartItemDTO:
    product_id: int
    name: str
    quantity: int
    price: int

    @property
    def total(self):
        return self.price * self.quantity


@dataclass
class CartDTO:
    items: list[CartItemDTO]
    total: int
    order_id: Optional[int] = None