# Copyright 2023 (c) Anna Schumaker.
"""A custom Gst.Bin with our audio filter effects."""
from gi.repository import GObject
from gi.repository import Gst
from . import replaygain


class Filter(Gst.Bin):
    """The audio filter element."""

    bg_enabled = GObject.Property(type=bool, default=False)
    bg_volume = GObject.Property(type=float, default=0.5)
    rg_mode = GObject.Property(type=str, default="disabled")

    def __init__(self):
        """Initialize the audio filter."""
        super().__init__()
        self._replaygain = replaygain.Filter()
        self._volume = Gst.ElementFactory.make("volume")

        self.add(self._replaygain)
        self.add(self._volume)

        rg_pad = self._replaygain.get_static_pad("src")
        rg_pad.link(self._volume.get_static_pad("sink"))

        self.__add_ghost_pad("sink", self._replaygain)
        self.__add_ghost_pad("src", self._volume)

        self.connect("notify", self.__notify)

    def __add_ghost_pad(self, pad: str, elm: Gst.Element) -> None:
        self.add_pad(Gst.GhostPad.new(pad, elm.get_static_pad(pad)))

    def __notify(self, filter: Gst.Bin, param: GObject.ParamSpec) -> None:
        match param.name:
            case "bg-enabled" | "bg-volume":
                vol = self.bg_volume if self.bg_enabled else 1.0
                if vol != self._volume.get_property("volume"):
                    vs = f"{round(vol * 100)}%" if self.bg_enabled else "off"
                    print(f"audio: setting background listening to {vs}")
                    self._volume.set_property("volume", vol)
            case "rg-mode":
                if self.rg_mode != self._replaygain.mode:
                    self._replaygain.mode = self.rg_mode