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}"

    def to_dict(self) -> dict[str, str | int | None]:
        return {
            "source": self.source,
            "external_id": self.external_id,
            "title": self.title,
            "description": self.description,
            "price": self.price,
            "price_amount": self.price_amount,
            "url": self.url,
            "category_id": self.category_id,
            "published_at": self.published_at,
            "seller_username": self.seller_username,
        }

    @classmethod
    def from_dict(cls, data: dict[str, str | int | None]) -> "Offer":
        return cls(
            source=str(data["source"]),
            external_id=str(data["external_id"]),
            title=str(data["title"]),
            description=str(data["description"]),
            price=str(data["price"]),
            price_amount=int(data["price_amount"]) if data["price_amount"] is not None else None,
            url=str(data["url"]),
            category_id=int(data["category_id"]),
            published_at=str(data["published_at"]),
            seller_username=str(data["seller_username"]) if data["seller_username"] is not None else None,
        )