from __future__ import annotations
from typing import Any, Optional


class AppError(Exception):
    status_code: int = 500
    code: str = "internal_error"

    def __init__(self, message: str, details: Optional[Any] = None) -> None:
        super().__init__(message)
        self.details = details

    def to_dict(self) -> dict:
        out: dict = {"error": self.code, "message": str(self)}
        if self.details is not None:
            out["details"] = self.details
        return out


class NotFoundError(AppError):
    status_code = 404
    code = "not_found"

    def __init__(self, resource: str, identifier: Any = None) -> None:
        msg = f"{resource} not found"
        if identifier is not None:
            msg += f": {identifier}"
        super().__init__(msg)


class AuthError(AppError):
    status_code = 401
    code = "unauthorized"


class ForbiddenError(AppError):
    status_code = 403
    code = "forbidden"


class ValidationError(AppError):
    status_code = 422
    code = "validation_error"

    def __init__(self, field: str, message: str) -> None:
        self.field = field
        super().__init__(f"{field}: {message}")

    def to_dict(self) -> dict:
        d = super().to_dict()
        d["field"] = self.field
        return d


class ConflictError(AppError):
    status_code = 409
    code = "conflict"