from __future__ import annotations

from dataclasses import dataclass
from typing import Any


@dataclass(slots=True)
class FieldError:
    field: str
    message: str
    code: str = "INVALID_VALUE"


class AppError(Exception):
    def __init__(
        self,
        detail: str,
        *,
        code: str = "APPLICATION_ERROR",
        status_code: int = 400,
        title: str = "请求处理失败",
        errors: list[FieldError] | None = None,
        context: dict[str, Any] | None = None,
    ) -> None:
        super().__init__(detail)
        self.detail = detail
        self.code = code
        self.status_code = status_code
        self.title = title
        self.errors = errors or []
        self.context = context or {}


class AuthenticationError(AppError):
    def __init__(self, detail: str = "请先登录") -> None:
        super().__init__(detail, code="AUTHENTICATION_REQUIRED", status_code=401, title="需要登录")


class ConflictError(AppError):
    def __init__(self, detail: str, code: str = "RESOURCE_CONFLICT") -> None:
        super().__init__(detail, code=code, status_code=409, title="状态冲突")


class ExternalServiceError(AppError):
    def __init__(self, detail: str, *, service: str, code: str = "UPSTREAM_ERROR") -> None:
        super().__init__(
            detail,
            code=code,
            status_code=502,
            title="外部服务异常",
            context={"service": service},
        )


class NotFoundError(AppError):
    def __init__(self, detail: str, code: str = "NOT_FOUND") -> None:
        super().__init__(detail, code=code, status_code=404, title="未找到")


class ValidationAppError(AppError):
    def __init__(
        self,
        detail: str,
        *,
        code: str = "VALIDATION_ERROR",
        errors: list[FieldError] | None = None,
    ) -> None:
        super().__init__(
            detail,
            code=code,
            status_code=422,
            title="配置校验失败",
            errors=errors,
        )