# Copyright 2022 (c) Anna Schumaker.
"""A custom Gtk.Box with controls for adjusting the volume."""
from gi.repository import GObject
from gi.repository import Gtk

STEP_SIZE = 0.05


def format_value_func(scale, value: float) -> str:
    """Format the volume value to a percentage."""
    return f"{round(value*100)} %"


class Controls(Gtk.Box):
    """A Gtk.Box containing widgets for adjusting the volume."""

    volume = GObject.Property(type=float, default=1.0)

    def __init__(self):
        """Initialize our volume controls."""
        super().__init__()
        self._decrement = Gtk.Button(icon_name="list-remove-symbolic",
                                     valign=Gtk.Align.END, has_frame=False,
                                     margin_bottom=6)
        self._adjustment = Gtk.Adjustment.new(1.0, 0.0, 1.0, STEP_SIZE, 0, 0)
        self._scale = Gtk.Scale(adjustment=self._adjustment, draw_value=True,
                                valign=Gtk.Align.END, hexpand=True)
        self._increment = Gtk.Button(icon_name="list-add-symbolic",
                                     valign=Gtk.Align.END, has_frame=False,
                                     margin_bottom=6)

        self._scale.set_format_value_func(format_value_func)

        self.append(self._decrement)
        self.append(self._scale)
        self.append(self._increment)

        self._decrement.connect("clicked", self.__decrement)
        self._scale.connect("value-changed", self.__value_changed)
        self._increment.connect("clicked", self.__increment)

        self.bind_property("volume", self._adjustment, "value",
                           GObject.BindingFlags.BIDIRECTIONAL)

    def __decrement(self, button: Gtk.Button) -> None:
        self._scale.set_value(self._scale.get_value() - STEP_SIZE)

    def __increment(self, button: Gtk.Button) -> None:
        self._scale.set_value(self._scale.get_value() + STEP_SIZE)

    def __value_changed(self, range: Gtk.Range) -> None:
        self.volume = range.get_value()