/*
 * -*- Mode:Vala; indent-tabs-mode:t; tab-width:4; encoding:utf8 -*-
 * Copyright 2016 Canonical Ltd.
 *
 * 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:
 *      Xavi Garcia <xavi.garcia.mena@canonical.com>
 */

using PulseAudio;
using Notify;
using Gee;

[DBus (name="org.ayatana.Greeter.List")]
interface GreeterListInterfaceAccess : Object
{
    public abstract async string get_active_entry () throws GLib.DBusError, GLib.IOError;
    public signal void entry_selected (string entry_name);
}

public class AccountsServiceAccess : Object
{
    private DBusProxy _user_proxy;
    private GreeterListInterfaceAccess _greeter_proxy;
    private double _volume = 0.0;
    private string _last_running_player = "";
    private bool _mute = false;
    private Cancellable _dbus_call_cancellable;

    public AccountsServiceAccess ()
    {
        _dbus_call_cancellable = new Cancellable ();
        setup_accountsservice.begin ();
    }

    ~AccountsServiceAccess ()
    {
        _dbus_call_cancellable.cancel ();
    }

    public string last_running_player
    {
        get
        {
            return _last_running_player;
        }
        set
        {
            sync_last_running_player_to_accountsservice.begin (value);
        }
    }

    public bool mute
    {
        get
        {
            return _mute;
        }
        set
        {
            sync_mute_to_accountsservice.begin (value);
        }
    }

    public double volume
    {
        get
        {
            return _volume;
        }
        set
        {
            sync_volume_to_accountsservice.begin (value);
        }
    }

    /* AccountsService operations */
    private void accountsservice_props_changed_cb (DBusProxy proxy, Variant changed_properties, string[]? invalidated_properties)
    {
        Variant volume_variant = changed_properties.lookup_value ("Volume", VariantType.DOUBLE);
        if (volume_variant != null) {
            var volume = volume_variant.get_double ();
            if (volume >= 0 && _volume != volume) {
                _volume = volume;
                this.notify_property("volume");
            }
        }

        Variant mute_variant = changed_properties.lookup_value ("Muted", VariantType.BOOLEAN);
        if (mute_variant != null) {
            _mute = mute_variant.get_boolean ();
            this.notify_property("mute");
        }

        Variant last_running_player_variant = changed_properties.lookup_value ("LastRunningPlayer", VariantType.STRING);
        if (last_running_player_variant != null) {
            _last_running_player = last_running_player_variant.get_string ();
            this.notify_property("last-running-player");
        }
    }

    private async void setup_user_proxy (string? username_in = null)
    {
        var username = username_in;
        _user_proxy = null;

        // Look up currently selected greeter user, if asked
        if (username == null) {
            try {
                username = yield _greeter_proxy.get_active_entry ();
                if (username == "" || username == null)
                    return;
            } catch (GLib.Error e) {
                warning ("unable to find Accounts path for user %s: %s", username == null ? "null" : username, e.message);
                return;
            }
        }

        // Get master AccountsService object
        DBusProxy accounts_proxy;
        try {
            accounts_proxy = yield DBusProxy.create_for_bus (BusType.SYSTEM, DBusProxyFlags.DO_NOT_LOAD_PROPERTIES | DBusProxyFlags.DO_NOT_CONNECT_SIGNALS, null, "org.freedesktop.Accounts", "/org/freedesktop/Accounts", "org.freedesktop.Accounts");
        } catch (GLib.Error e) {
            warning ("unable to get greeter proxy: %s", e.message);
            return;
        }

        // Find user's AccountsService object
        try {
            var user_path_variant = yield accounts_proxy.call ("FindUserByName", new Variant ("(s)", username), DBusCallFlags.NONE, -1);
            string user_path;
            if (user_path_variant.check_format_string ("(o)", true)) {
                user_path_variant.get ("(o)", out user_path);
#if HAS_UT_ACCTSERVICE_SOUND_SETTINGS
                _user_proxy = yield DBusProxy.create_for_bus (BusType.SYSTEM, DBusProxyFlags.GET_INVALIDATED_PROPERTIES, null, "org.freedesktop.Accounts", user_path, "com.ubuntu.AccountsService.Sound");
#else
                _user_proxy = yield DBusProxy.create_for_bus (BusType.SYSTEM, DBusProxyFlags.GET_INVALIDATED_PROPERTIES, null, "org.freedesktop.Accounts", user_path, "org.ayatana.AccountsService.Sound");
#endif
            } else {
                warning ("Unable to find user name after calling FindUserByName. Expected type: %s and obtained %s", "(o)", user_path_variant.get_type_string () );
                return;
            }
        } catch (GLib.Error e) {
            warning ("unable to find Accounts path for user %s: %s", username, e.message);
            return;
        }

        // Get current values and listen for changes
        _user_proxy.g_properties_changed.connect (accountsservice_props_changed_cb);
        try {
            var props_variant = yield _user_proxy.get_connection ().call (_user_proxy.get_name (), _user_proxy.get_object_path (), "org.freedesktop.DBus.Properties", "GetAll", new Variant ("(s)", _user_proxy.get_interface_name ()), null, DBusCallFlags.NONE, -1);
            if (props_variant.check_format_string ("(@a{sv})", true)) {
                Variant props;
                props_variant.get ("(@a{sv})", out props);
                accountsservice_props_changed_cb(_user_proxy, props, null);
            } else {
                warning ("Unable to get accounts service properties after calling GetAll. Expected type: %s and obtained %s", "(@a{sv})", props_variant.get_type_string () );
                return;
            }
        } catch (GLib.Error e) {
            debug("Unable to get properties for user %s at first try: %s", username, e.message);
        }
    }

    private void greeter_user_changed (string username)
    {
        setup_user_proxy.begin (username);
    }

    private async void setup_accountsservice ()
    {
        if (Environment.get_variable ("XDG_SESSION_CLASS") == "greeter") {
            try {
                _greeter_proxy = yield Bus.get_proxy (BusType.SESSION, "org.ayatana.Greeter", "/list");
            } catch (GLib.Error e) {
                warning ("unable to get greeter proxy: %s", e.message);
                return;
            }
            _greeter_proxy.entry_selected.connect (greeter_user_changed);
            yield setup_user_proxy ();
        } else {
            // We are in a user session.  We just need our own proxy
            unowned string username = Environment.get_variable ("USER");
            if (username != null && username != "") {
                yield setup_user_proxy (username);
            }
        }
    }

    private async void sync_last_running_player_to_accountsservice (string last_running_player)
    {
        if (_user_proxy == null)
            return;

        try {
            yield _user_proxy.get_connection ().call (_user_proxy.get_name (), _user_proxy.get_object_path (), "org.freedesktop.DBus.Properties", "Set", new Variant ("(ssv)", _user_proxy.get_interface_name (), "LastRunningPlayer", new Variant ("s", last_running_player)), null, DBusCallFlags.NONE, -1, _dbus_call_cancellable);
        } catch (GLib.Error e) {
            warning ("unable to sync last running player %s to AccountsService: %s",last_running_player, e.message);
        }
        _last_running_player = last_running_player;
    }

    private async void sync_volume_to_accountsservice (double volume)
    {
        if (_user_proxy == null)
            return;

        try {
            yield _user_proxy.get_connection ().call (_user_proxy.get_name (), _user_proxy.get_object_path (), "org.freedesktop.DBus.Properties", "Set", new Variant ("(ssv)", _user_proxy.get_interface_name (), "Volume", new Variant ("d", volume)), null, DBusCallFlags.NONE, -1, _dbus_call_cancellable);
        } catch (GLib.Error e) {
            warning ("unable to sync volume %f to AccountsService: %s", volume, e.message);
        }
    }

    private async void sync_mute_to_accountsservice (bool mute)
    {
        if (_user_proxy == null)
            return;

        try {
            yield _user_proxy.get_connection ().call (_user_proxy.get_name (), _user_proxy.get_object_path (), "org.freedesktop.DBus.Properties", "Set", new Variant ("(ssv)", _user_proxy.get_interface_name (), "Muted", new Variant ("b", mute)), null, DBusCallFlags.NONE, -1, _dbus_call_cancellable);
        } catch (GLib.Error e) {
            warning ("unable to sync mute %s to AccountsService: %s", mute ? "true" : "false", e.message);
        }
    }
}