"""General-purpose utility tools."""

from __future__ import annotations

from fabledassistant.services.tools._registry import tool


@tool(
    name="calculate",
    description=(
        "Evaluate a mathematical expression and return the exact result. Use this for any "
        "arithmetic, percentages, unit conversions, or multi-step calculations where precision "
        "matters. Supports standard math operators (+, -, *, /, **, %) and all Python math "
        "module functions (sqrt, log, sin, cos, floor, ceil, etc.)."
    ),
    parameters={
        "expression": {"type": "string", "description": "A valid Python math expression (e.g. '(450 * 1.13) / 12', 'sqrt(144)', 'log(1000, 10)')"},
    },
    required=["expression"],
)
async def calculate_tool(*, user_id, arguments, **_ctx):
    import math as _math

    expr = str(arguments.get("expression", "")).strip()
    if not expr:
        return {"success": False, "error": "expression is required"}
    allowed_names = {k: v for k, v in vars(_math).items() if not k.startswith("_")}
    allowed_names["abs"] = abs
    allowed_names["round"] = round
    try:
        result = eval(expr, {"__builtins__": {}}, allowed_names)  # noqa: S307
    except Exception as calc_err:
        return {"success": False, "error": f"Could not evaluate expression: {calc_err}"}
    return {"success": True, "type": "calculation", "data": {"expression": expr, "result": result}}