"""应用异常定义：所有业务异常均继承自 AppError

错误码规范：
- 1xxx: 请求/鉴权错误
- 2xxx: 浏览器资源错误
- 3xxx: Cloudflare/反爬相关错误
- 4xxx: 页面解析错误
"""


class AppError(Exception):
    """应用基础异常，携带错误码、HTTP 状态码和是否可重试信息"""

    def __init__(
        self,
        message: str,
        code: str,
        err_code: int,
        retryable: bool = False,
        status_code: int = 400,
        headers: dict[str, str] | None = None,
    ):
        super().__init__(message)
        self.message = message
        self.code = code
        self.err_code = err_code
        self.retryable = retryable
        self.status_code = status_code
        self.headers = headers


class AuthenticationError(AppError):
    """鉴权失败（Bearer Token 无效或缺失）"""

    def __init__(self, message: str = "Invalid credentials"):
        super().__init__(
            message=message,
            code="AUTH_INVALID",
            err_code=1001,
            retryable=False,
            status_code=401,
            headers={"WWW-Authenticate": "Bearer"},
        )


class BrowserUnavailableError(AppError):
    """浏览器不可用（未启用或启动失败）"""

    def __init__(self, message: str = "Browser pool is unavailable"):
        super().__init__(message=message, code="BROWSER_UNAVAILABLE", err_code=2001, retryable=True)


class ResourceBusyError(AppError):
    """浏览器资源繁忙（获取页面槽位超时）"""

    def __init__(self, message: str = "Timed out while waiting for a browser slot"):
        super().__init__(message=message, code="RESOURCE_BUSY", err_code=2002, retryable=True)


class CloudflareChallengeError(AppError):
    """Cloudflare 挑战未在规定时间内通过"""

    def __init__(self, message: str = "Cloudflare challenge did not clear in time"):
        super().__init__(message=message, code="CLOUDFLARE_CHALLENGE", err_code=3001, retryable=True)


class UpstreamBlockedError(AppError):
    """上游请求被 Cloudflare 阻断（如 1020/403 错误）"""

    def __init__(self, message: str = "The upstream request was blocked"):
        super().__init__(message=message, code="UPSTREAM_BLOCKED", err_code=3002, retryable=True)


class ScrapeParseError(AppError):
    """页面解析失败"""

    def __init__(self, message: str = "Failed to parse the target page"):
        super().__init__(message=message, code="PARSE_ERROR", err_code=4001, retryable=False)