"""异常与错误分类。

WCF 的错误是 HTML 页面，真正的信息藏在 "The exception message is '...'" 里。
分类的目的是决定「重试 / 跳过 / 整批中止」，而不是把所有失败都当网络问题重试。
"""

from __future__ import annotations

from enum import StrEnum


class Category(StrEnum):
    NET = "NET"            # 网络层：可重试
    SP_MISSING = "SP_MISSING"  # 存储过程不存在：配置/版本问题，不重试
    PARAM = "PARAM"        # 参数错误/类型转换：数据问题，不重试
    EXCEL = "EXCEL"        # Excel 解析失败（Column1 != 0）
    TFS = "TFS"            # 推送 TFS 失败
    AUTH = "AUTH"          # 登录失败
    UNKNOWN = "UNKNOWN"


class QtError(RuntimeError):
    """带分类的接口错误。"""

    def __init__(self, message: str, category: Category = Category.UNKNOWN, *, retryable: bool = False):
        super().__init__(message)
        self.message = message
        self.category = category
        self.retryable = retryable

    def __str__(self) -> str:  # pragma: no cover - 直通
        return f"[{self.category}] {self.message}"

    @classmethod
    def from_http(cls, status: int, body: str) -> "QtError":
        """把 WCF 的 HTML 错误页转成可读错误。"""
        message = extract_exception_message(body) or f"HTTP {status}"
        lowered = message.lower()
        if "could not find stored procedure" in lowered:
            return cls(message, Category.SP_MISSING)
        if "missing parameter" in lowered or "conversion" in lowered or "procedure or function" in lowered:
            return cls(message, Category.PARAM)
        if status >= 500:
            return cls(message, Category.NET, retryable=True)
        return cls(message, Category.UNKNOWN)


def extract_exception_message(body: str) -> str:
    """从 WCF 错误页里抠出真正的异常文本。"""
    import html
    import re

    match = re.search(r"exception message is '(.*?)'\s*\.?\s*See server logs", body, re.S)
    if match:
        return html.unescape(match.group(1)).strip()
    plain = re.sub(r"<[^>]+>", " ", body)
    plain = html.unescape(re.sub(r"\s+", " ", plain)).strip()
    return plain[:400]