app/core/exceptions.py

from fastapi import HTTPException, status
from typing import Any, Optional

class AppError(HTTPException):
    def __init__(
        self,
        status_code: int,
        detail: Any = None,
        headers: Optional[dict[str, Any]] = None,
    ) -> None:
        super().__init__(status_code=status_code, detail=detail, headers=headers)

class NotFoundError(AppError):
    def __init__(self, resource: str = "Resource"):
        super().__init__(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"{resource} not found"
        )

class AuthenticationError(AppError):
    def __init__(self, detail: str = "Could not validate credentials"):
        super().__init__(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=detail,
            headers={"WWW-Authenticate": "Bearer"},
        )

class DuplicateError(AppError):
    def __init__(self, detail: str = "Data already exists"):
        super().__init__(
            status_code=status.HTTP_409_CONFLICT,
            detail=detail
        )