#!/usr/bin/env python3
"""Reveal/focus a pane in the Hermes desktop GUI.

Lives in the ``desktop_ui`` toolset (like the other GUI affordances), which the
GUI gateway enables only for desktop-sourced sessions. Emits ``pane.reveal``
through the shared ``desktop_ui`` bridge; the renderer runs each pane's own
reveal path and only acts on the active window (a background turn never moves
the user's focus). To show a URL/file, use ``open_preview``; to close it, use
``close_preview``.
"""

import json

from tools import desktop_ui
from tools.registry import registry, tool_error

PANES = ("chat", "files", "terminal", "review", "sessions")


def focus_pane_tool(pane: str) -> str:
    """Ask the desktop GUI to reveal and focus ``pane``."""
    name = (pane or "").strip().lower()
    if name not in PANES:
        return tool_error(f"pane must be one of: {', '.join(PANES)}.")

    try:
        ok = desktop_ui.emit("pane.reveal", {"pane": name})
    except Exception as exc:
        return tool_error(f"Failed to focus the {name} pane: {exc}")
    if not ok:
        return tool_error("Pane focus is only available in the Hermes desktop app.")

    return json.dumps({"success": True, "pane": name}, ensure_ascii=False)


FOCUS_PANE_SCHEMA = {
    "name": "focus_pane",
    "description": (
        "Reveal and focus a Hermes desktop pane when the user asks to see it: "
        "chat, files, terminal, review (git diff), or sessions. For URLs/"
        "files use the desktop_preview tool instead."
    ),
    "parameters": {
        "type": "object",
        "properties": {
            "pane": {
                "type": "string",
                "enum": list(PANES),
                "description": "Which pane to reveal.",
            },
        },
        "required": ["pane"],
    },
}


registry.register(
    name="focus_pane",
    toolset="desktop_ui",
    schema=FOCUS_PANE_SCHEMA,
    handler=lambda args, **kw: focus_pane_tool(pane=args.get("pane", "")),
    emoji="🪟",
)