"""天气查询工具"""
import httpx
from typing import Optional


async def get_weather(
    city: str,
    units: str = "metric",
    language: str = "zh_cn"
) -> dict:
    """
    获取指定城市的天气信息

    Args:
        city: 城市名称，支持中文城市名（如"北京"、"上海"）或英文城市名（如"Beijing"、"London"）
        units: 单位系统，"metric"（摄氏度）或 "imperial"（华氏度），默认为 "metric"
        language: 返回结果的语言，默认为中文（zh_cn）

    Returns:
        dict: 包含天气信息的字典，包括：
            - city: 城市名称
            - temperature: 当前温度
            - description: 天气描述
            - humidity: 湿度百分比
            - wind_speed: 风��
            - feels_like: 体感温度
            - temp_min: 最低温度
            - temp_max: 最高温度

    Example:
        >>> result = await get_weather("北京")
        >>> print(result['temperature'])
        15

        >>> result = await get_weather("Tokyo", units="metric")
        >>> print(result['description'])
        晴朗
    """
    # 使用 OpenWeatherMap API 的免费端点
    # 注意：实际使用需要申请 API key，这里使用 wttr.in 作为免费替代
    base_url = "https://wttr.in"

    params = {
        "format": "j1",  # JSON 格式
        "lang": language,
    }

    # 处理单位系统
    if units == "imperial":
        params["u"] = "f"  # 华氏度
    else:
        params["u"] = "c"  # 摄氏度（默认）

    try:
        async with httpx.AsyncClient(timeout=10.0) as client:
            response = await client.get(f"{base_url}/{city}", params=params)
            response.raise_for_status()
            data = response.json()

            # 解析当前天气
            current = data.get("current_condition", [{}])[0]

            # 解析位置信息
            location = data.get("nearest_area", [{}])[0]

            return {
                "city": location.get("areaName", [{}])[0].get("value", city),
                "country": location.get("country", [{}])[0].get("value", ""),
                "temperature": float(current.get("temp_C", 0) if units == "metric" else current.get("temp_F", 0)),
                "description": current.get("weatherDesc", [{}])[0].get("value", "未知"),
                "humidity": int(current.get("humidity", 0)),
                "wind_speed": float(current.get("windspeedKmph", 0)),
                "feels_like": float(current.get("FeelsLikeC", 0) if units == "metric" else current.get("FeelsLikeF", 0)),
                "temp_min": float(current.get("temp_C", 0) if units == "metric" else current.get("temp_F", 0)),  # wttr.in 不提供 min/max，使用当前温度
                "temp_max": float(current.get("temp_C", 0) if units == "metric" else current.get("temp_F", 0)),
                "uv_index": int(current.get("uvIndex", 0)),
            }
    except httpx.TimeoutException:
        return {
            "error": "请求超时，请稍后重试",
            "city": city
        }
    except httpx.HTTPError as e:
        return {
            "error": f"获取天气信息失败: {str(e)}",
            "city": city
        }
    except (KeyError, IndexError, ValueError) as e:
        return {
            "error": f"解析天气数据失败: {str(e)}",
            "city": city
        }