"""
机外工具执行：天气（Open-Meteo）、搜索摘要（DuckDuckGo Instant Answer）。
仅用标准库 HTTP，无额外依赖。
"""
from __future__ import annotations

import json
import urllib.error
import urllib.parse
import urllib.request
from typing import Any, Mapping

from loguru import logger

# WMO Weather interpretation codes (Open-Meteo)，精简中文
_WMO_SHORT = {
    0: "晴",
    1: "大部晴",
    2: "局部多云",
    3: "多云",
    45: "雾",
    48: "雾凇",
    51: "小毛毛雨",
    53: "中毛毛雨",
    55: "大毛毛雨",
    56: "冻毛毛雨",
    57: "强冻毛毛雨",
    61: "小雨",
    63: "中雨",
    65: "大雨",
    66: "冻雨",
    67: "强冻雨",
    71: "小雪",
    73: "中雪",
    75: "大雪",
    77: "雪粒",
    80: "小阵雨",
    81: "阵雨",
    82: "强阵雨",
    85: "小阵雪",
    86: "阵雪",
    95: "雷暴",
    96: "雷暴伴冰雹",
    99: "强雷暴伴冰雹",
}


def _http_get_json(url: str, timeout: float = 12.0) -> Any:
    req = urllib.request.Request(
        url,
        headers={"User-Agent": "VoiceLLMCloud/1.0 (tool_executor)"},
        method="GET",
    )
    with urllib.request.urlopen(req, timeout=timeout) as resp:
        raw = resp.read().decode("utf-8", errors="replace")
    return json.loads(raw)


def _weather_desc(code: int | None) -> str:
    if code is None:
        return "未知"
    return _WMO_SHORT.get(int(code), f"代码{code}")


def get_current_weather(location: str) -> str:
    """
    Open-Meteo：地理编码 + current 天气，无需 API Key。
    """
    loc = (location or "").strip()
    if not loc:
        return "错误：地点为空"

    try:
        q = urllib.parse.quote(loc)
        geo_url = (
            "https://geocoding-api.open-meteo.com/v1/search"
            f"?name={q}&count=1&language=zh&format=json"
        )
        geo = _http_get_json(geo_url)
        results = geo.get("results") if isinstance(geo, dict) else None
        if not results:
            return f"未找到地点「{loc}」，请说具体城市名。"
        g0 = results[0]
        lat, lon = float(g0["latitude"]), float(g0["longitude"])
        label = g0.get("name") or loc
        admin = g0.get("admin1") or g0.get("country") or ""
        place = f"{label}" + (f"（{admin}）" if admin else "")

        lat_q = urllib.parse.quote(str(lat))
        lon_q = urllib.parse.quote(str(lon))
        wx_url = (
            "https://api.open-meteo.com/v1/forecast?"
            f"latitude={lat_q}&longitude={lon_q}"
            "&current=temperature_2m,relative_humidity_2m,apparent_temperature,"
            "weather_code,wind_speed_10m,wind_direction_10m"
            "&timezone=auto&forecast_days=1"
        )
        wx = _http_get_json(wx_url)
        cur = wx.get("current") if isinstance(wx, dict) else None
        if not cur:
            return f"无法读取 {place} 的实时天气数据。"

        t = cur.get("temperature_2m")
        feels = cur.get("apparent_temperature")
        rh = cur.get("relative_humidity_2m")
        wcode = cur.get("weather_code")
        ws = cur.get("wind_speed_10m")
        wd = cur.get("wind_direction_10m")
        desc = _weather_desc(wcode)

        parts = [
            f"{place}当前天气：{desc}",
            f"气温约{t}°C" if t is not None else "",
            f"体感约{feels}°C" if feels is not None else "",
            f"相对湿度约{rh}%" if rh is not None else "",
        ]
        if ws is not None:
            wind_part = f"风速约{ws}m/s"
            if wd is not None:
                wind_part += f"、风向{wd}°"
            parts.append(wind_part)
        text = "，".join(p for p in parts if p)
        return text or "天气数据不完整"
    except urllib.error.URLError as e:
        logger.warning(f"[tool] weather URLError: {e}")
        return f"天气服务暂时不可用：{e}"
    except Exception as e:
        logger.warning(f"[tool] weather error: {e}")
        return f"查询天气失败：{e}"


def web_search(query: str) -> str:
    """
    DuckDuckGo HTML API：Instant Answer + 相关主题摘要，无 API Key。
    命中差时返回简短说明，避免模型胡编。
    """
    q = (query or "").strip()[:200]
    if not q:
        return "错误：搜索词为空"

    try:
        qs = urllib.parse.quote(q)
        url = (
            "https://api.duckduckgo.com/"
            f"?q={qs}&format=json&no_html=1&no_redirect=1&t=voicellmcloud"
        )
        # DDG 偶发对 urllib 限流；仍优于无搜索
        data = _http_get_json(url, timeout=14.0)
        if not isinstance(data, dict):
            return "搜索无结构化结果，请换个说法或稍后重试。"

        chunks: list[str] = []
        ab = data.get("AbstractText")
        if isinstance(ab, str) and ab.strip():
            chunks.append(ab.strip())
        ans = data.get("Answer")
        if isinstance(ans, str) and ans.strip():
            chunks.append(ans.strip())
        elif ans not in (None, ""):
            chunks.append(str(ans))

        for rt in (data.get("RelatedTopics") or [])[:4]:
            if isinstance(rt, dict) and isinstance(rt.get("Text"), str):
                t = rt["Text"].strip()
                if t:
                    chunks.append(t)
            elif isinstance(rt, dict) and "Topics" in rt:
                for sub in (rt.get("Topics") or [])[:2]:
                    if isinstance(sub, dict) and isinstance(sub.get("Text"), str):
                        s = sub["Text"].strip()
                        if s:
                            chunks.append(s)

        if not chunks:
            heading = data.get("Heading")
            if isinstance(heading, str) and heading.strip():
                return (
                    f"未检索到「{q}」的摘要（仅标题：{heading.strip()}）。"
                    "可改用更短关键词或指定天气类用问天气。"
                )
            return f"未检索到「{q}」的公开摘要，请缩短或更换关键词。"

        out = "\n".join(dict.fromkeys(chunks))  # 去重保序
        if len(out) > 6000:
            out = out[:6000] + "\n…(截断)"
        return out
    except urllib.error.URLError as e:
        logger.warning(f"[tool] web_search URLError: {e}")
        return f"搜索服务暂时不可用：{e}"
    except Exception as e:
        logger.warning(f"[tool] web_search error: {e}")
        return f"搜索失败：{e}"


def dispatch_tool(name: str, arguments: str | Mapping[str, Any] | None) -> str:
    """根据函数名与参数 JSON 执行工具，返回给模型的字符串。"""
    if not name:
        return "错误：未指定工具名"
    if isinstance(arguments, str):
        arg_str = arguments.strip() or "{}"
        try:
            parsed: Any = json.loads(arg_str)
        except json.JSONDecodeError as e:
            return f"工具参数不是合法 JSON：{e}"
    elif isinstance(arguments, Mapping):
        parsed = dict(arguments)
    elif arguments is None:
        parsed = {}
    else:
        return "错误：工具参数类型不支持"

    if not isinstance(parsed, dict):
        return "错误：工具参数须为 JSON 对象"

    n = name.strip().lower()
    if n == "get_current_weather":
        loc = str(parsed.get("location", "")).strip()
        return get_current_weather(loc)
    if n == "web_search":
        query = str(parsed.get("query", "")).strip()
        return web_search(query)
    return f"未知工具：{name}"