/*
 * Copyright 2014 Canonical Ltd.
 * Copyright 2021-2023 Robert Tari
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *      Ted Gould <ted@canonical.com>
 *      Robert Tari <robert@tari.in>
 */

[DBus (name="org.ayatana.greeter")]
public interface AyatanaGreeterList : Object {
    public abstract async string GetUser () throws GLib.DBusError, GLib.IOError;
    public signal void UserChanged (string user);
}

public class MediaPlayerListGreeter : MediaPlayerList {
    string? selected_user = null;
    AyatanaGreeterList? proxy = null;
    HashTable<string, MediaPlayerUser> players = new HashTable<string, MediaPlayerUser>(str_hash, str_equal);

    public MediaPlayerListGreeter () {
        Bus.get_proxy.begin<AyatanaGreeterList> (
            BusType.SESSION,
            "org.ayatana.greeter",
            "/org/ayatana/greeter",
            DBusProxyFlags.NONE,
            null,
            new_proxy);
    }

    void new_proxy (GLib.Object? obj, AsyncResult res) {
        try {
            this.proxy = Bus.get_proxy.end(res);

            this.proxy.UserChanged.connect(active_user_changed);
            this.proxy.GetUser.begin ((obj, res) => {
                try {
                    var list = (obj as AyatanaGreeterList);

                    if (list != null)
                    {
                        var value = list.GetUser.end(res);
                        active_user_changed(value);
                    }
                } catch (Error e) {
                    warning("Unable to get active entry: %s", e.message);
                }
            });
        } catch (Error e) {
            this.proxy = null;
            warning("Unable to create proxy to the greeter: %s", e.message);
        }
    }

    void active_user_changed (string active_user) {
        /* No change, move along */
        if (selected_user == active_user) {
            return;
        }

        debug(@"Active user changed to: $active_user");

        var old_user = selected_user;

        /* Protect against a null user */
        if (active_user != "" && active_user[0] != '*') {
            selected_user = active_user;
        } else {
            debug(@"Blocking active user change for '$active_user'");
            selected_user = null;
        }

        if (selected_user != null && !players.contains(selected_user)) {
            players.insert(selected_user, new MediaPlayerUser(selected_user));
        }

        if (old_user != null) {
            var old_player = players.lookup(old_user);
            debug("Removing player for user: %s", old_user);
            player_removed(old_player);
        }

        if (selected_user != null) {
            var new_player = players.lookup(selected_user);

            if (new_player != null) {
                debug("Adding player for user: %s", selected_user);
                player_added(new_player);
            }
        }
    }

    /* We need to have an iterator for the interface, but eh, we can
       only ever have one player for the current user */
    public class Iterator : MediaPlayerList.Iterator {
        int i = 0;
        MediaPlayerListGreeter list;

        public Iterator (MediaPlayerListGreeter in_list) {
            list = in_list;
        }

        public override MediaPlayer? next_value () {
            MediaPlayer? retval = null;

            if (i == 0 && list.selected_user != null) {
                retval = list.players.lookup(list.selected_user);
            }
            i++;

            return retval;
        }
    }

    public override MediaPlayerList.Iterator iterator() {
        return new Iterator(this) as MediaPlayerList.Iterator;
    }
}