theme.py

"""
theme.py - Theme support.

Copyright (c) EDCD, All Rights Reserved
Licensed under the GNU General Public License v2 or later.
See LICENSE file.

Because of various ttk limitations this app is an unholy mix of Tk and ttk widgets.
So can't use ttk's theme support. So have to change colors manually.
"""

import os
import sys
import tkinter as tk
from tkinter import font as tk_font
from tkinter import ttk
from typing import Any
from collections.abc import Callable
from l10n import translations as tr
from config import config
from EDMCLogging import get_main_logger
from ttkHyperlinkLabel import HyperlinkLabel

logger = get_main_logger()

if __debug__:
    from traceback import print_exc

# Can't use Case matching here due to bug in flake8-naming
if sys.platform == "win32":
    import ctypes
    from ctypes.wintypes import DWORD, LPCVOID, LPCWSTR
    import win32gui
    import win32con
    AddFontResourceEx = ctypes.windll.gdi32.AddFontResourceExW
    AddFontResourceEx.argtypes = [LPCWSTR, DWORD, LPCVOID]
    AddFontResourceEx.restype = ctypes.c_int
    FR_PRIVATE = 0x10
    FR_NOT_ENUM = 0x20
    font_path = str(config.respath_path / 'EUROCAPS.TTF')
    if not AddFontResourceEx(font_path, FR_PRIVATE, None):
        raise RuntimeError(f"Failed to load font {font_path}")
    dpy = None

elif sys.platform == "linux":
    from ctypes import POINTER, Structure, byref, c_char_p, c_int, c_long, c_uint, c_ulong, c_void_p, cdll

    XID = c_ulong
    Window = XID
    Atom = c_ulong
    Display = c_void_p

    PropModeReplace = 0
    PropModePrepend = 1
    PropModeAppend = 2

    MWM_HINTS_FUNCTIONS = 1 << 0
    MWM_HINTS_DECORATIONS = 1 << 1
    MWM_HINTS_INPUT_MODE = 1 << 2
    MWM_HINTS_STATUS = 1 << 3
    MWM_FUNC_ALL = 1 << 0
    MWM_FUNC_RESIZE = 1 << 1
    MWM_FUNC_MOVE = 1 << 2
    MWM_FUNC_MINIMIZE = 1 << 3
    MWM_FUNC_MAXIMIZE = 1 << 4
    MWM_FUNC_CLOSE = 1 << 5
    MWM_DECOR_ALL = 1 << 0
    MWM_DECOR_BORDER = 1 << 1
    MWM_DECOR_RESIZEH = 1 << 2
    MWM_DECOR_TITLE = 1 << 3
    MWM_DECOR_MENU = 1 << 4
    MWM_DECOR_MINIMIZE = 1 << 5
    MWM_DECOR_MAXIMIZE = 1 << 6

    class MotifWmHints(Structure):
        """MotifWmHints structure."""

        _fields_ = [
            ('flags', c_ulong),
            ('functions', c_ulong),
            ('decorations', c_ulong),
            ('input_mode', c_long),
            ('status', c_ulong),
        ]

    # workaround for https://github.com/EDCD/EDMarketConnector/issues/568
    if not os.getenv("EDMC_NO_UI"):
        try:
            xlib = cdll.LoadLibrary('libX11.so.6')
            XInternAtom = xlib.XInternAtom
            XInternAtom.argtypes = [POINTER(Display), c_char_p, c_int]
            XInternAtom.restype = Atom
            XChangeProperty = xlib.XChangeProperty
            XChangeProperty.argtypes = [POINTER(Display), Window, Atom, Atom, c_int,
                                        c_int, POINTER(MotifWmHints), c_int]
            XChangeProperty.restype = c_int
            XFlush = xlib.XFlush
            XFlush.argtypes = [POINTER(Display)]
            XFlush.restype = c_int
            XOpenDisplay = xlib.XOpenDisplay
            XOpenDisplay.argtypes = [c_char_p]
            XOpenDisplay.restype = POINTER(Display)
            XQueryTree = xlib.XQueryTree
            XQueryTree.argtypes = [POINTER(Display), Window, POINTER(Window),
                                   POINTER(Window), POINTER(Window), POINTER(c_uint)]
            XQueryTree.restype = c_int
            dpy = xlib.XOpenDisplay(None)
            if not dpy:
                raise Exception("Can't find your display, can't continue")

            motif_wm_hints_property = XInternAtom(dpy, b'_MOTIF_WM_HINTS', False)
            motif_wm_hints_normal = MotifWmHints(
                MWM_HINTS_FUNCTIONS | MWM_HINTS_DECORATIONS,
                MWM_FUNC_RESIZE | MWM_FUNC_MOVE | MWM_FUNC_MINIMIZE | MWM_FUNC_CLOSE,
                MWM_DECOR_BORDER | MWM_DECOR_RESIZEH | MWM_DECOR_TITLE | MWM_DECOR_MENU | MWM_DECOR_MINIMIZE,
                0, 0
            )
            motif_wm_hints_dark = MotifWmHints(
                MWM_HINTS_FUNCTIONS | MWM_HINTS_DECORATIONS,
                MWM_FUNC_RESIZE | MWM_FUNC_MOVE | MWM_FUNC_MINIMIZE | MWM_FUNC_CLOSE,
                0, 0, 0
            )
        except Exception:
            if __debug__:
                print_exc()
            dpy = None
    else:
        dpy = None
else:
    dpy = None


class _Theme:

    # Enum ?  Remember these are, probably, based on 'value' of a tk
    # RadioButton set.  Looking in prefs.py, they *appear* to be hard-coded
    # there as well.
    THEME_DEFAULT = 0
    THEME_DARK = 1
    THEME_TRANSPARENT = 2

    def __init__(self) -> None:
        self.active: int | None = None  # Starts out with no theme
        self.minwidth: int | None = None
        self.widgets: dict[tk.Widget | tk.BitmapImage, set[str]] = {}
        self.widgets_pair: list[tuple[tuple[Any, ...], dict[str, Any]]] = []
        self.defaults: dict[str, Any] = {}
        self.current: dict[str, Any] = {}
        self.default_ui_scale: float | None = None  # None == not yet known
        self.startup_ui_scale: int | None = None

    def register(self, widget: tk.Widget | tk.BitmapImage) -> None:  # noqa: CCR001
        # Note widget and children for later application of a theme. Note if
        # the widget has explicit fg or bg attributes.
        if not isinstance(widget, (tk.Widget, tk.BitmapImage)):
            raise TypeError(f'Expected widget, got {type(widget)}')
        if not self.defaults:
            self.defaults = {
                'fg': tk.Label()['foreground'],         # SystemButtonText, systemButtonText
                'bg': tk.Label()['background'],         # SystemButtonFace, White
                'font': tk.Label()['font'],               # TkDefaultFont
                'bitmapfg': tk.BitmapImage()['foreground'],   # '-foreground {} {} #000000 #000000'
                'bitmapbg': tk.BitmapImage()['background'],   # '-background {} {} {} {}'
                'entryfg': tk.Entry()['foreground'],         # SystemWindowText, Black
                'entrybg': tk.Entry()['background'],         # SystemWindow, systemWindowBody
                'entryfont': tk.Entry()['font'],               # TkTextFont
                'frame': tk.Frame()['background'],         # SystemButtonFace, systemWindowBody
                'menufg': tk.Menu()['foreground'],          # SystemMenuText,
                'menubg': tk.Menu()['background'],          # SystemMenu,
                'menufont': tk.Menu()['font'],                # TkTextFont
            }

        if widget not in self.widgets:
            # No general way to tell whether the user has overridden, so compare against widget-type specific defaults
            attribs = set()
            match widget:
                case tk.BitmapImage():
                    if widget['foreground'] not in ('', self.defaults['bitmapfg']):
                        attribs.add('fg')
                    if widget['background'] not in ('', self.defaults['bitmapbg']):
                        attribs.add('bg')
                case tk.Entry() | ttk.Entry():
                    if widget['foreground'] not in ('', self.defaults['entryfg']):
                        attribs.add('fg')
                    if widget['background'] not in ('', self.defaults['entrybg']):
                        attribs.add('bg')
                    if 'font' in widget.keys() and str(widget['font']) not in ('', self.defaults['entryfont']):
                        attribs.add('font')
                case tk.Canvas() | tk.Frame() | ttk.Frame():
                    if (('background' in widget.keys() or isinstance(widget, tk.Canvas))
                            and widget['background'] not in ('', self.defaults['frame'])):
                        attribs.add('bg')
                case HyperlinkLabel():
                    pass
                case tk.Menu():
                    if widget['foreground'] not in ('', self.defaults['menufg']):
                        attribs.add('fg')
                    if widget['background'] not in ('', self.defaults['menubg']):
                        attribs.add('bg')
                    if widget['font'] not in ('', self.defaults['menufont']):
                        attribs.add('font')
                case _:
                    w_keys = widget.keys() if hasattr(widget, 'keys') else []
                    if 'foreground' in w_keys and widget['foreground'] not in ('', self.defaults['fg']):
                        attribs.add('fg')
                    if 'background' in w_keys and widget['background'] not in ('', self.defaults['bg']):
                        attribs.add('bg')
                    if 'font' in w_keys and widget['font'] not in ('', self.defaults['font']):
                        attribs.add('font')
            self.widgets[widget] = attribs

        if isinstance(widget, (tk.Frame, ttk.Frame)):
            for child in widget.winfo_children():
                self.register(child)  # type: ignore

    def register_alternate(self, pair: tuple, gridopts: dict) -> None:
        self.widgets_pair.append((pair, gridopts))

    def button_bind(self, widget: tk.Widget, command: Callable, image: tk.BitmapImage | None = None) -> None:
        widget.bind('<Button-1>', command)
        widget.bind('<Enter>', lambda e: self._enter(e, widget=widget, image=image))
        widget.bind('<Leave>', lambda e: self._leave(e, widget=widget, image=image))

    def _enter(self, event: tk.Event, widget: tk.Widget | None = None,  # noqa: CCR001
               image: tk.BitmapImage | None = None) -> None:
        """Handle mouse entering a widget or image."""
        if widget is not None:
            # Only apply foreground/background if the widget supports them
            config_keys = widget.keys() if hasattr(widget, 'keys') else []
            kwargs = {}
            if 'foreground' in config_keys and self.current.get('highlightforeground'):
                kwargs['foreground'] = self.current['highlightforeground']
            if 'background' in config_keys and self.current.get('highlightbackground'):
                kwargs['background'] = self.current['highlightbackground']
            if kwargs:
                widget.configure(**kwargs)

        if image is not None and not isinstance(image, tk.PhotoImage):
            # PhotoImage cannot be configured with fg/bg, skip safely
            try:
                config_keys = image.keys() if hasattr(image, 'keys') else []
                kwargs = {}
                if 'foreground' in config_keys and self.current.get('highlightforeground'):
                    kwargs['foreground'] = self.current['highlightforeground']
                if 'background' in config_keys and self.current.get('highlightbackground'):
                    kwargs['background'] = self.current['highlightbackground']
                if kwargs:
                    image.configure(**kwargs)
            except tk.TclError:
                # silently ignore unsupported image types
                pass

    def _leave(self, event: tk.Event, widget: tk.Widget | None = None,   # noqa: CCR001
               image: tk.BitmapImage | None = None) -> None:
        """Handle mouse leaving a widget or image."""
        if widget is not None:
            config_keys = widget.keys() if hasattr(widget, 'keys') else []
            kwargs = {}
            if 'foreground' in config_keys and self.current.get('foreground'):
                kwargs['foreground'] = self.current['foreground']
            if 'background' in config_keys and self.current.get('background'):
                kwargs['background'] = self.current['background']
            if kwargs:
                widget.configure(**kwargs)

        if image is not None and not isinstance(image, tk.PhotoImage):
            # Skip PhotoImage objects; safely handle other types
            try:
                config_keys = image.keys() if hasattr(image, 'keys') else []
                kwargs = {}
                if 'foreground' in config_keys and self.current.get('foreground'):
                    kwargs['foreground'] = self.current['foreground']
                if 'background' in config_keys and self.current.get('background'):
                    kwargs['background'] = self.current['background']
                if kwargs:
                    image.configure(**kwargs)
            except tk.TclError:
                pass

    # Set up colors
    def _colors(self, root: tk.Tk, theme: int) -> None:
        style = ttk.Style()
        if sys.platform == 'linux':
            style.theme_use('clam')

        # Default dark theme colors
        if not config.get_str('dark_text'):
            config.set('dark_text', '#ff8000')  # "Tangerine" in OSX color picker
        if not config.get_str('dark_highlight'):
            config.set('dark_highlight', 'white')

        match theme:
            case self.THEME_DEFAULT:
                self.current = {
                    'background': style.lookup('TLabel', 'background'),
                    'foreground': style.lookup('TLabel', 'foreground'),
                    'activebackground': 'SystemHighlight' if sys.platform == 'win32' else style.lookup('TLabel',
                                                                                                       'background',
                                                                                                       ['active']),
                    'activeforeground': 'SystemHighlightText' if sys.platform == 'win32' else style.lookup('TLabel',
                                                                                                           'foreground',
                                                                                                           ['active']),
                    'disabledforeground': style.lookup('TLabel', 'foreground', ['disabled']),
                    'highlight': 'blue',
                    'font': 'TkDefaultFont',
                }
            case _:
                r, g, b = root.winfo_rgb(config.get_str('dark_text'))

                # Font only supports Latin 1 / Supplement / Extended, and a
                # few General Punctuation and Mathematical Operators
                # LANG: Label for commander name in main window
                use_euro_caps = theme > 1 and not (0x250 < ord(tr.tl('Cmdr')[0]) < 0x3000)
                chosen_font = tk_font.Font(family='Euro Caps', size=10,
                                           weight=tk_font.NORMAL) if use_euro_caps else 'TkDefaultFont'

                self.current = {
                    'background': 'grey4',
                    'foreground': config.get_str('dark_text'),
                    'activebackground': config.get_str('dark_text'),
                    'activeforeground': 'grey4',
                    'disabledforeground': f'#{int(r / 384):02x}{int(g / 384):02x}{int(b / 384):02x}',
                    'highlight': config.get_str('dark_highlight'),
                    'font': chosen_font,
                }

    def update(self, widget: tk.Widget) -> None:
        """
        Apply current theme to a widget and its children.

        Also, register it for future updates.
        :param widget: Target widget.
        """
        if not isinstance(widget, (tk.Widget, tk.BitmapImage)):
            raise TypeError(f'Expected widget, got {type(widget)}')
        if not self.current:
            return  # No need to call this for widgets created in plugin_app()

        self.register(widget)
        self._update_widget(widget)
        if isinstance(widget, (tk.Frame, ttk.Frame)):
            for child in widget.winfo_children():
                self._update_widget(child)  # type: ignore

    # Apply current theme to a single widget
    def _update_widget(self, widget: tk.Widget | tk.BitmapImage) -> None:  # noqa: CCR001
        if widget not in self.widgets:
            w_class = widget.winfo_class() if isinstance(widget, tk.Widget) else ''
            w_keys = widget.keys() if isinstance(widget, tk.Widget) else []
            w_text = widget["text"] if "text" in w_keys else ""
            raise ValueError(f'{w_class} {widget} "{w_text}"')

        attribs = self.widgets.get(widget, set())

        try:
            match widget:
                case tk.BitmapImage():
                    if 'fg' not in attribs:
                        widget['foreground'] = self.current['foreground']
                    if 'bg' not in attribs:
                        widget['background'] = self.current['background']

                case _ if 'cursor' in widget.keys() and str(widget['cursor']) not in ('', 'arrow'):
                    # Hack - highlight widgets like HyperlinkLabel with a non-default cursor
                    if 'fg' not in attribs:
                        widget['foreground'] = self.current['highlight']
                        if 'insertbackground' in widget.keys():  # tk.Entry
                            widget['insertbackground'] = self.current['foreground']
                    if 'bg' not in attribs:
                        widget['background'] = self.current['background']
                        if 'highlightbackground' in widget.keys():  # tk.Entry
                            widget['highlightbackground'] = self.current['background']
                    if 'font' not in attribs:
                        widget['font'] = self.current['font']

                case _ if 'activeforeground' in widget.keys():
                    # e.g. tk.Button, tk.Label, tk.Menu
                    if 'fg' not in attribs:
                        widget['foreground'] = self.current['foreground']
                        widget['activeforeground'] = self.current['activeforeground']
                        widget['disabledforeground'] = self.current['disabledforeground']
                    if 'bg' not in attribs:
                        widget['background'] = self.current['background']
                        widget['activebackground'] = self.current['activebackground']
                    if 'font' not in attribs:
                        widget['font'] = self.current['font']

                case _ if 'foreground' in widget.keys():
                    # e.g. ttk.Label
                    if 'fg' not in attribs:
                        widget['foreground'] = self.current['foreground']
                    if 'bg' not in attribs:
                        widget['background'] = self.current['background']
                    if 'font' not in attribs:
                        widget['font'] = self.current['font']

                case _ if 'background' in widget.keys() or isinstance(widget, tk.Canvas):
                    # e.g. Frame, Canvas
                    if 'bg' not in attribs:
                        widget['background'] = self.current['background']
                        widget['highlightbackground'] = self.current['disabledforeground']

        except Exception:
            logger.exception(f'Plugin widget issue? {widget=}')

    # Apply configured theme
    def apply(self, root: tk.Tk) -> None:  # noqa: CCR001
        theme = config.get_int('theme')
        self._colors(root, theme)

        # Apply colors
        for widget in list(self.widgets.keys()):
            if isinstance(widget, tk.Widget) and not widget.winfo_exists():
                self.widgets.pop(widget)  # has been destroyed
            else:
                self._update_widget(widget)

        # Switch menus
        for pair, gridopts in self.widgets_pair:
            for widget in pair:
                if isinstance(widget, tk.Widget):
                    widget.grid_remove()

            if isinstance(pair[0], tk.Menu):
                match theme:
                    case self.THEME_DEFAULT:
                        root['menu'] = pair[0]
                    case _:  # Dark *or* Transparent
                        root['menu'] = ''
                        pair[theme].grid(**gridopts)
            else:
                pair[theme].grid(**gridopts)

        if self.active == theme:
            return  # Don't need to mess with the window manager
        self.active = theme

        if sys.platform == 'win32':
            root.overrideredirect(theme != self.THEME_DEFAULT)
            root.attributes("-transparentcolor", 'grey4' if theme == self.THEME_TRANSPARENT else '')

            root.withdraw()
            root.update_idletasks()  # Size and windows styles get recalculated here
            hwnd = win32gui.GetParent(root.winfo_id())
            win32gui.SetWindowLong(
                hwnd,
                win32con.GWL_STYLE,
                win32gui.GetWindowLong(hwnd, win32con.GWL_STYLE) & ~win32con.WS_MAXIMIZEBOX
            )

            ex_style = win32con.WS_EX_APPWINDOW
            if theme == self.THEME_TRANSPARENT:
                ex_style |= win32con.WS_EX_LAYERED

            win32gui.SetWindowLong(hwnd, win32con.GWL_EXSTYLE, ex_style)
            root.deiconify()
            root.wait_visibility()  # need main window to be displayed before returning
        else:
            root.withdraw()
            root.update_idletasks()  # Size gets recalculated here
            if dpy:
                xroot, parent, children = Window(), Window(), Window()
                nchildren = c_uint()
                XQueryTree(dpy, root.winfo_id(), byref(xroot), byref(parent), byref(children), byref(nchildren))
                wm_hints = motif_wm_hints_normal if theme == self.THEME_DEFAULT else motif_wm_hints_dark
                XChangeProperty(dpy, parent, motif_wm_hints_property, motif_wm_hints_property, 32, PropModeReplace,
                                wm_hints, 5)
                XFlush(dpy)
            else:
                root.overrideredirect(theme != self.THEME_DEFAULT)
            root.deiconify()
            root.wait_visibility()  # need main window to be displayed before returning

        if not self.minwidth:
            self.minwidth = root.winfo_width()  # Minimum width = width on first creation
            root.minsize(self.minwidth, -1)


# Singleton
theme = _Theme()