import json
from typing import Any, Dict

import httpx
from langchain_core.tools import BaseTool


class RestApiTool(BaseTool):
    """RESTful API 调用工具"""

    name: str = "rest_api"
    description: str = (
        "调用 RESTful API。输入为 JSON 字符串，示例："
        '{"method":"GET","url":"https://example.com/api","params":{},"headers":{},"body":null,"timeout":30}'
    )

    def _run(self, payload: str) -> str:
        """执行 RESTful API 请求"""
        try:
            data = json.loads(payload)
        except Exception as e:
            return f"请求参数解析失败: {e}"

        method = str(data.get("method", "GET")).upper()
        url = data.get("url")
        params: Dict[str, Any] = data.get("params") or {}
        headers: Dict[str, Any] = data.get("headers") or {}
        body = data.get("body")
        timeout = float(data.get("timeout", 30))

        if not url:
            return "缺少 url"

        try:
            with httpx.Client(timeout=timeout) as client:
                response = client.request(
                    method=method,
                    url=url,
                    params=params,
                    headers=headers,
                    json=body,
                )
            return json.dumps(
                {
                    "status_code": response.status_code,
                    "headers": dict(response.headers),
                    "text": response.text,
                },
                ensure_ascii=False,
            )
        except Exception as e:
            return f"请求失败: {e}"

    async def _arun(self, payload: str) -> str:
        """工具的异步版本"""
        try:
            data = json.loads(payload)
        except Exception as e:
            return f"请求参数解析失败: {e}"

        method = str(data.get("method", "GET")).upper()
        url = data.get("url")
        params: Dict[str, Any] = data.get("params") or {}
        headers: Dict[str, Any] = data.get("headers") or {}
        body = data.get("body")
        timeout = float(data.get("timeout", 30))

        if not url:
            return "缺少 url"

        try:
            async with httpx.AsyncClient(timeout=timeout) as client:
                response = await client.request(
                    method=method,
                    url=url,
                    params=params,
                    headers=headers,
                    json=body,
                )
            return json.dumps(
                {
                    "status_code": response.status_code,
                    "headers": dict(response.headers),
                    "text": response.text,
                },
                ensure_ascii=False,
            )
        except Exception as e:
            return f"请求失败: {e}"