"""
tools/calculator.py
数学计算工具 —— 支持基本四则运算及常用数学函数
配置通过 settings.tools['calculator'] 读取
"""

import math
import operator
from typing import Any

from config.settings import settings
from tools.base_tool import BaseTool
from utils.logger import get_logger

logger = get_logger("TOOL.Calculator")


def _cfg(key: str, fallback=None):
    return settings.tools['calculator'].get(key, fallback)


class Tool(BaseTool):
    name        = "calculator"
    description = (
        "执行数学计算，支持四则运算、幂运算、开方、三角函数、对数等。"
        "输入数学表达式字符串，返回计算结果。"
    )
    parameters  = {
        "type": "object",
        "properties": {
            "expression": {
                "type":        "string",
                "description": (
                    "数学表达式，例如: '2 + 3 * 4', 'sqrt(16)', "
                    "'sin(3.14159/2)', 'log(100, 10)', '2 ** 10'"
                ),
            },
        },
        "required": ["expression"],
    }

    # 安全的内置函数白名单
    _SAFE_GLOBALS: dict[str, Any] = {
        "__builtins__": {},
        # 基本数学
        "abs":   abs,
        "round": round,
        "pow":   pow,
        "min":   min,
        "max":   max,
        # math 模块常用函数
        "sqrt":  math.sqrt,
        "ceil":  math.ceil,
        "floor": math.floor,
        "log":   math.log,
        "log2":  math.log2,
        "log10": math.log10,
        "exp":   math.exp,
        "sin":   math.sin,
        "cos":   math.cos,
        "tan":   math.tan,
        "asin":  math.asin,
        "acos":  math.acos,
        "atan":  math.atan,
        "atan2": math.atan2,
        "pi":    math.pi,
        "e":     math.e,
        "inf":   math.inf,
        "factorial": math.factorial,
        "gcd":   math.gcd,
        "hypot": math.hypot,
    }

    def execute(self, expression: str = "", **_) -> str:
        if not expression or not expression.strip():
            return "❌ 参数错误: expression 不能为空"

        expr = expression.strip()
        logger.info(f"🔢 计算表达式: {expr}")

        # 安全检查：禁止危险关键字
        forbidden = ["import", "exec", "eval", "open", "os", "sys",
                     "__", "compile", "globals", "locals", "getattr"]
        for kw in forbidden:
            if kw in expr:
                return f"❌ 安全限制: 表达式包含禁止关键字 '{kw}'"

        try:
            precision = _cfg('precision', 10)
            result    = eval(expr, self._SAFE_GLOBALS, {})  # noqa: S307

            # 格式化输出
            if isinstance(result, float):
                # 去除多余尾零
                formatted = f"{result:.{precision}f}".rstrip("0").rstrip(".")
            elif isinstance(result, complex):
                formatted = str(result)
            else:
                formatted = str(result)

            logger.info(f"✅ 计算结果: {expr} = {formatted}")
            return f"{expr} = {formatted}"

        except ZeroDivisionError:
            return f"❌ 计算错误: 除零错误  表达式: {expr}"
        except OverflowError:
            return f"❌ 计算错误: 数值溢出  表达式: {expr}"
        except ValueError as e:
            return f"❌ 计算错误: {e}  表达式: {expr}"
        except SyntaxError:
            return f"❌ 语法错误: 无法解析表达式 '{expr}'"
        except Exception as e:
            return f"❌ 计算失败: {e}  表达式: {expr}"