"""Kivy observable adapter for the framework-neutral translator."""

from kivy._event import Observable

from katrain.core.lang import DEFAULT_LANGUAGE, Lang as CoreLang
from katrain.gui.theme import Theme


class Lang(CoreLang, Observable):
    observers = []

    def __init__(self, lang):
        Observable.__init__(self)
        self.callbacks = []
        super().__init__(lang)

    def set_widget_font(self, widget):
        widget.font_name = self.font_name or Theme.DEFAULT_FONT
        for sub_widget in [getattr(widget, "_hint_lbl", None), getattr(widget, "_msg_lbl", None)]:
            if sub_widget:
                sub_widget.font_name = widget.font_name

    def fbind(self, name, func, *args):
        if name != "_":
            return Observable.fbind(self, name, func, *args)
        widget, _property, *_ = args[0]
        self.observers.append((widget, func, args))
        self.set_widget_font(widget)

    def funbind(self, name, func, *args):
        if name != "_":
            return Observable.funbind(self, name, func, *args)
        widget, *_ = args[0]
        key = (widget, func, args)
        if key in self.observers:
            self.observers.remove(key)

    def switch_lang(self, lang):
        previous = self.lang
        super().switch_lang(lang)
        if lang == previous:
            return
        for widget, func, args in self.observers:
            try:
                func(args[0], None, None)
                self.set_widget_font(widget)
            except ReferenceError:
                pass
        for callback in self.callbacks:
            callback(self)


i18n = Lang(DEFAULT_LANGUAGE)


def rank_label(rank):
    if rank is None:
        return "??k"
    if rank >= 0.5:
        return f"{rank:.0f}{i18n._('strength:dan')}"
    return f"{1-rank:.0f}{i18n._('strength:kyu')}"

__all__ = ["DEFAULT_LANGUAGE", "i18n", "rank_label"]