"""代理层错误类型（§5.3 错误码映射）。"""
from __future__ import annotations


class ProxyError(Exception):
    """代理层错误基类（HTTP 语义由子类表达）。"""
    status_code = 500
    code = "proxy_error"


class ProxyAuthError(ProxyError):
    """无效/注销 key。"""
    status_code = 401
    code = "invalid_key"


class BalanceError(ProxyError):
    """余额或日上限不足（预扣失败）。"""
    status_code = 402
    code = "insufficient_balance"


class SuspendedError(ProxyError):
    """学生账户被停用。"""
    status_code = 403
    code = "student_suspended"


class QuotaError(ProxyError):
    """限流（rpm / 日请求上限 / 并发上限）。"""
    status_code = 429
    code = "rate_limited"


class BodyTooLargeError(ProxyError):
    """请求体超过 max_body_chars。"""
    status_code = 413
    code = "body_too_large"


class UpstreamError(ProxyError):
    """上游失败（首 token 前 failover 均失败）。"""
    status_code = 502
    code = "upstream_failed"


class AdminAuthError(ProxyError):
    """管理面鉴权失败。"""
    status_code = 401
    code = "admin_unauthorized"