from dataclasses import dataclass
import uuid

@dataclass
class Reward:
    name: str
    description: str
    cost: int
    image_id: str | None = None
    id: str | None = None

    def __post_init__(self):
        if self.id is None:
            self.id = str(uuid.uuid4())

    @classmethod
    def from_dict(cls, d: dict):
        return cls(
            id=d.get('id'),
            name=d.get('name'),
            description=d.get('description'),
            cost=d.get('cost', 0),
            image_id=d.get('image_id')
        )

    def to_dict(self):
        return {
            'id': self.id,
            'name': self.name,
            'description': self.description,
            'cost': self.cost,
            'image_id': self.image_id
        }