"""博查 (Bocha AI) Web Search API 客户端,共享给 web_search tool。"""
from __future__ import annotations

import os
from dataclasses import dataclass
from pathlib import Path
from typing import Optional

import httpx
import yaml

from core.paths import ROOT

_BOCHA_YAML = ROOT / "config" / "web" / "bocha.yaml"


class BochaError(RuntimeError):
    """博查 API 调用失败的统一异常。"""


@dataclass
class BochaConfig:
    api_key: str
    base_url: str

    @classmethod
    def load(cls, path: Optional[Path] = None) -> Optional["BochaConfig"]:
        """读 bocha.yaml + 解析 env 拿 api_key。

        api_key env 未设 → 返 None(caller 据此决定是否注册 tool)。
        yaml 不存在 → 返 None。
        """
        p = path or _BOCHA_YAML
        if not p.exists():
            return None
        data = yaml.safe_load(p.read_text(encoding="utf-8")) or {}
        env = data.get("bocha_api_key_env") or "BOCHA_API_KEY"
        key = os.environ.get(env, "").strip()
        if not key:
            return None
        return cls(
            api_key=key,
            base_url=str(data.get("bocha_base_url") or "https://api.bochaai.com/v1").rstrip("/"),
        )


class BochaClient:
    """轻量 httpx 封装: POST /v1/web-search, Bearer auth + 异常翻译。"""

    def __init__(self, cfg: BochaConfig, timeout_s: float = 15.0) -> None:
        self.cfg = cfg
        self._client = httpx.Client(
            base_url=cfg.base_url,
            headers={
                "Authorization": f"Bearer {cfg.api_key}",
                "Content-Type": "application/json",
            },
            timeout=timeout_s,
        )

    def search(self, query: str, count: int = 10, freshness: str = "noLimit") -> dict:
        """调用博查 Web Search API,返回原始 dict。

        freshness 可选: noLimit, oneDay, oneWeek, oneMonth, oneYear
        count: 1-50
        """
        body = {"query": query, "count": min(max(count, 1), 50), "freshness": freshness}
        try:
            resp = self._client.post("/web-search", json=body)
        except httpx.TimeoutException as e:
            raise BochaError(f"博查搜索超时: {e}") from e
        except httpx.HTTPError as e:
            raise BochaError(f"博查网络错误: {e}") from e
        return self._parse(resp)

    @staticmethod
    def _parse(resp: httpx.Response) -> dict:
        if resp.status_code >= 400:
            try:
                msg = resp.json().get("message", resp.text[:300])
            except ValueError:
                msg = resp.text[:300]
            raise BochaError(f"博查 API → HTTP {resp.status_code}: {msg}")
        try:
            return resp.json()
        except ValueError as e:
            raise BochaError(f"博查 API → invalid JSON: {e}") from e

    def close(self) -> None:
        self._client.close()

    def __enter__(self) -> "BochaClient":
        return self

    def __exit__(self, *_: object) -> None:
        self.close()