from __future__ import annotations

from dataclasses import dataclass


@dataclass(frozen=True)
class Offer:
    source: str
    external_id: str
    title: str
    description: str
    price: str
    price_amount: int | None
    url: str
    category_id: int
    published_at: str
    seller_username: str | None = None

    @property
    def dedup_key(self) -> str:
        return f"{self.source}:{self.external_id}"