"""Meta-tool: dynamically create new tools at runtime."""

from __future__ import annotations

import importlib
import textwrap
from pathlib import Path

from . import tool


@tool("build_tool", "Create a new tool from a description. The agent writes Python code with @tool decorator.", category="meta")
def build_tool(name: str, description: str, code: str, ctx: dict = None) -> str:
    """Generate a new tool module and hot-load it.

    Args:
        name: Tool name (snake_case)
        description: What the tool does
        code: Full Python code for the tool function (must use @tool decorator)
    """
    if not name.isidentifier():
        return f"Invalid tool name: {name}. Must be a valid Python identifier."

    # Wrap code in a module with the import
    module_code = textwrap.dedent(f'''\
        """Auto-generated tool: {description}"""
        from __future__ import annotations
        from . import tool

        {code}
    ''')

    # Write to tools directory
    tools_dir = Path(__file__).parent
    file_path = tools_dir / f"{name}.py"
    if file_path.exists():
        return f"Tool module '{name}' already exists. Choose a different name."

    file_path.write_text(module_code, encoding="utf-8")

    # Hot-import the new module
    try:
        importlib.import_module(f".{name}", package=__package__)
        return f"Tool '{name}' created and loaded successfully at {file_path}"
    except Exception as e:
        # Clean up on failure
        file_path.unlink(missing_ok=True)
        return f"Failed to load tool '{name}': {e}"