from typing import Annotated, Any
from bson import ObjectId
from pydantic import BaseModel, BeforeValidator


def validate_object_id(v: Any) -> str:
    """ObjectId <-> str 변환을 위한 유효성 검증기"""
    if isinstance(v, ObjectId):
        return str(v)
    if isinstance(v, str) and ObjectId.is_valid(v):
        return v
    raise ValueError(f"Invalid ObjectId: {v}")


PyObjectId = Annotated[str, BeforeValidator(validate_object_id)]


class ErrorResponse(BaseModel):
    """표준 에러 응답"""
    detail: str


class PaginatedResponse(BaseModel):
    """페이지네이션 응답 래퍼"""
    items: list[Any]
    total: int
    page: int
    limit: int
    total_pages: int