appearance.py

# WriterAgent - AI Writing Assistant for LibreOffice
# Copyright (c) 2026 KeithCu (modifications and relicensing)
#
# SPDX-License-Identifier: GPL-3.0-or-later
"""Shared LibreOffice theme / appearance detection.

Central source for light/dark decisions and colors derived from VCL StyleSettings
on a window (FieldColor, DialogColor etc.). Used by chat sidebar and the Monaco
Python editor (so the webview chrome + Monaco theme track the LO UI automatically).

Detection is heuristic (luminance of FieldColor) because LO exposes limited
color tokens via UNO and "System" mode reflects the desktop at the time the
window was created. This matches the logic previously only in rich_text.py.
"""

import logging
from typing import Any

from plugin.framework.uno_context import get_desktop

log = logging.getLogger(__name__)

# Safe light fallback (matches prior defaults)
_FALLBACK_BG = 0xE0E1E2
_FALLBACK_USER = 0x2A6099
_FALLBACK_ASSISTANT = 0x1E293B


def get_style_window(doc: Any = None, style_window: Any = None, ctx: Any = None) -> Any | None:
    """Return a window object that exposes .StyleSettings, or None.

    Preference order: explicit style_window, doc's frame container, current
    desktop frame's container (for cases with no doc like Run Python Script).
    """
    win = style_window
    if win is None and doc is not None:
        try:
            controller = doc.getCurrentController()
            if controller:
                frame = controller.getFrame()
                if frame:
                    win = frame.getContainerWindow()
        except Exception as e:
            log.debug("get_style_window: doc frame lookup failed: %s", e)

    if win is None and ctx is not None:
        try:
            desktop = get_desktop(ctx)
            # Try current frame first (active window)
            frame = desktop.getCurrentFrame()
            if frame:
                win = frame.getContainerWindow()
            if win is None:
                # Fallback to current component's controller
                comp = desktop.getCurrentComponent()
                if comp is not None and hasattr(comp, "getCurrentController"):
                    ctrl = comp.getCurrentController()
                    if ctrl:
                        f = getattr(ctrl, "getFrame", lambda: None)()
                        if f:
                            win = f.getContainerWindow()
        except Exception as e:
            log.debug("get_style_window: ctx/desktop lookup failed: %s", e)

    return win


def _luminance(color: int) -> float:
    if not isinstance(color, int):
        return 255.0
    r = (color >> 16) & 0xFF
    g = (color >> 8) & 0xFF
    b = color & 0xFF
    return 0.2126 * r + 0.7152 * g + 0.0722 * b


def get_theme_colors(doc: Any = None, style_window: Any = None, ctx: Any = None) -> tuple[int, int, int]:
    """Retrieve theme-aware colors based on StyleSettings.

    Returns (bg_color, user_color, assistant_color) as 0xRRGGBB ints.
    Delegates to the same logic used for the Monaco editor's is_dark decision.
    Safe fallback is a soft light gray.
    """
    win = get_style_window(doc=doc, style_window=style_window, ctx=ctx)
    try:
        if win and hasattr(win, "StyleSettings"):
            style_settings = win.StyleSettings
            if style_settings:
                field_color = getattr(style_settings, "FieldColor", 0xFFFFFF)
                if isinstance(field_color, int):
                    if _luminance(field_color) < 128:
                        # Dark
                        return field_color, 0x60A5FA, 0xE2E8F0
                    # Light: darken DialogColor a bit for nice contrast
                    dialog_color = getattr(style_settings, "DialogColor", 0xEFF0F1)
                    if isinstance(dialog_color, int):
                        r = int(((dialog_color >> 16) & 0xFF) * 0.94)
                        g = int(((dialog_color >> 8) & 0xFF) * 0.94)
                        b = int((dialog_color & 0xFF) * 0.94)
                        light_bg = (r << 16) | (g << 8) | b
                        return light_bg, 0x2A6099, 0x1E293B
                    return 0xE0E1E2, 0x2A6099, 0x1E293B
    except Exception as e:
        log.debug("Failed to resolve theme colors from StyleSettings: %s", e)
    return _FALLBACK_BG, _FALLBACK_USER, _FALLBACK_ASSISTANT


def get_monaco_theme_info(doc: Any = None, style_window: Any = None, ctx: Any = None) -> dict[str, Any]:
    """Return theme descriptor for the Python Monaco editor.

    The dict is sent over the IPC load (or a later 'theme' update) message.
    JS uses "monaco" for monaco.editor.setTheme and "is_dark" to toggle
    CSS classes on the toolbar chrome so the whole pywebview matches LO.

    We keep the decision in one place with the chat sidebar.
    Richer palette (hex colors etc.) can be added later without protocol break.
    """
    win = get_style_window(doc=doc, style_window=style_window, ctx=ctx)
    is_dark = False
    bg = _FALLBACK_BG
    try:
        if win and hasattr(win, "StyleSettings"):
            style_settings = win.StyleSettings
            if style_settings:
                field_color = getattr(style_settings, "FieldColor", 0xFFFFFF)
                if isinstance(field_color, int):
                    if _luminance(field_color) < 128:
                        is_dark = True
                        bg = field_color
                    else:
                        dialog_color = getattr(style_settings, "DialogColor", 0xEFF0F1)
                        if isinstance(dialog_color, int):
                            r = int(((dialog_color >> 16) & 0xFF) * 0.94)
                            g = int(((dialog_color >> 8) & 0xFF) * 0.94)
                            b = int((dialog_color & 0xFF) * 0.94)
                            bg = (r << 16) | (g << 8) | b
                        else:
                            bg = 0xE0E1E2
    except Exception as e:
        log.debug("get_monaco_theme_info failed: %s", e)

    return {
        "monaco": "vs-dark" if is_dark else "vs",
        "is_dark": is_dark,
        "bg": bg,
    }


# Back-compat re-exports for any direct imports (rare)
__all__ = ["get_style_window", "get_theme_colors", "get_monaco_theme_info"]