# Copyright 2021 (c) Anna Schumaker.
from gi.repository import GObject
from gi.repository import Gst


class ReplayGainSink(Gst.Bin):
    def __init__(self):
        Gst.Bin.__init__(self)
        self.selector  = Gst.ElementFactory.make("output-selector")
        self.funnel    = Gst.ElementFactory.make("funnel")
        self.audiosink = Gst.ElementFactory.make("autoaudiosink")
        self.rgvolume  = Gst.ElementFactory.make("rgvolume")
        self.rglimiter = Gst.ElementFactory.make("rglimiter")

        for element in [ self.selector, self.funnel, self.audiosink,
                         self.rgvolume, self.rglimiter ]:
            self.add(element)

        # No ReplayGain: selector -> funnel -> audiosink
        self.shortcut = self.selector.get_request_pad("src_%u")
        self.shortcut.link(self.funnel.get_request_pad("sink_%u"))
        self.funnel.link(self.audiosink)

        # Replaygain: selector -> rgvolume -> rglimiter -> funnel -> audiosink
        self.replaygain = self.selector.get_request_pad("src_%u")
        self.replaygain.link(self.rgvolume.get_static_pad("sink"))
        self.rgvolume.link(self.rglimiter)
        self.rglimiter.get_static_pad("src").link(
                                    self.funnel.get_request_pad("sink_%u"))

        self.selector.set_property("pad-negotiation-mode", 1)
        self.selector.set_property("active-pad", self.shortcut)

        pad = self.selector.get_static_pad("sink")
        ghost = Gst.GhostPad.new("sink", pad)
        ghost.set_active(True)
        self.add_pad(ghost)

    @GObject.Property
    def mode(self):
        if self.selector.get_property("active-pad") == self.shortcut:
            return "disabled"
        album_mode = self.rgvolume.get_property("album-mode")
        return "album" if album_mode else "track"

    @mode.setter
    def mode(self, mode):
        if mode == "disabled":
            self.selector.set_property("active-pad", self.shortcut)
        else:
            self.rgvolume.set_property("album-mode", mode == "album")
            self.selector.set_property("active-pad", self.replaygain)