nix-flake/home/ags-config/modules/media.ts

import { Accessor, createConnection, getScope, Scope } from "ags";
import { createScopedConnection, decoder } from "./utils";

import AstalMpris from "gi://AstalMpris";
import GObject from "gi://GObject?version=2.0";
import { property, register } from "ags/gobject";


@register({ GTypeName: "Media" })
export default class Media extends GObject.Object {
    private static instance: Media;
    public static readonly dummyPlayer = {
        available: false,
        busName: "dummy_player",
        bus_name: "dummy_player"
    } as AstalMpris.Player;

    @property(AstalMpris.Player)
    player: AstalMpris.Player = Media.dummyPlayer;

    constructor(scope: Scope) {
        super();
        
        scope.run(() => {
            const firstPlayer = AstalMpris.get_default().players[0];
            if(firstPlayer) 
                this.player = firstPlayer;

            createScopedConnection(
                AstalMpris.get_default(), 
                "player-added", 
                (player) => {
                    if(player.available) 
                        this.player = player;
                }
            );

            createScopedConnection(
                AstalMpris.get_default(),
                "player-closed", (closedPlayer) => {
                    const players = AstalMpris.get_default().players.filter(pl => pl?.available && 
                        pl.busName !== closedPlayer.busName);

                    // go back to first player(if available) when the active player is closed
                    if(players.length > 0 && players[0]) {
                        this.player = players[0];
                        return;
                    } 
                    
                    this.player = Media.dummyPlayer;
                }
            );
        });
    }

    public static getDefault(): Media {
        if(!this.instance)
            this.instance = new Media(getScope());

        return this.instance;
    }

    public static accessMediaUrl(player: AstalMpris.Player): Accessor<string|undefined> {
        return createConnection(player.get_meta("xesam:url"),
            [player, "notify::metadata", () => player.get_meta("xesam:url")]
        ).as(url => {
            const byteString = url?.get_data_as_bytes();

            return byteString ? 
                decoder.decode(byteString.toArray())
            : undefined;
          })
    }

    
    public static getMediaUrl(player: AstalMpris.Player): string|undefined {
        if(!player.available) return;

        const meta = player.get_meta("xesam:url");
        const byteString = meta?.get_data_as_bytes();

        return byteString ? 
            decoder.decode(byteString.toArray())
        : undefined;
    }
}