Introduce SystemUpdateProvider interface

src/Application.vala

@@ -80,9 +80,9 @@ public sealed class SettingsDaemon.Application : Gtk.Application {
     protected override bool dbus_register (DBusConnection connection, string object_path) throws Error {
         base.dbus_register (connection, object_path);
 
-        if (!SettingsDaemon.Utils.is_sysupdate ()) {
-            connection.register_object (object_path, new Backends.SystemUpdate ());
+        connection.register_object (object_path, new Backends.SystemUpdate ());
 
+        if (!SettingsDaemon.Utils.is_sysupdate ()) {
 #if UBUNTU_DRIVERS
             connection.register_object (object_path, new Backends.UbuntuDrivers ());
 #endif

src/Backends/SystemUpdate.vala → src/Backends/SystemUpdate/PackageKit.vala

@@ -5,18 +5,9 @@
  * Authored by: Leonhard Kargl <leo.kargl@proton.me>
  */
 
-[DBus (name="io.elementary.settings_daemon.SystemUpdate")]
-public class SettingsDaemon.Backends.SystemUpdate : Object {
-    public struct UpdateDetails {
-        string[] packages;
-        uint64 size;
-        Pk.Info[] info;
-    }
-
+public class SettingsDaemon.Backends.PackageKit : Object, SystemUpdateProvider {
     private const string NOTIFICATION_ID = "system-update";
 
-    public signal void state_changed ();
-
     private static Settings settings = new GLib.Settings ("io.elementary.settings-daemon.system-update");
 
     private PkUtils.CurrentState current_state;

src/Backends/SystemUpdate/SystemUpdate.vala

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2023 elementary, Inc. (https://elementary.io)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * Authored by: Leonhard Kargl <leo.kargl@proton.me>
+ */
+
+[DBus (name="io.elementary.settings_daemon.SystemUpdate")]
+public class SettingsDaemon.Backends.SystemUpdate : Object {
+    public signal void state_changed ();
+
+    private SystemUpdateProvider? provider;
+
+    construct {
+        if (SettingsDaemon.Utils.is_sysupdate ()) {
+            return;
+        }
+
+        provider = new PackageKit ();
+        provider.state_changed.connect (() => state_changed ());
+    }
+
+    public async void check_for_updates (bool force, bool notify) throws DBusError, IOError {
+        if (provider == null) {
+            throw new IOError.NOT_SUPPORTED ("No system update provider available");
+        }
+
+        yield provider.check_for_updates (force, notify);
+    }
+
+    public async void update () throws DBusError, IOError {
+        if (provider == null) {
+            throw new IOError.NOT_SUPPORTED ("No system update provider available");
+        }
+
+        yield provider.update ();
+    }
+
+    public void cancel () throws DBusError, IOError {
+        if (provider == null) {
+            throw new IOError.NOT_SUPPORTED ("No system update provider available");
+        }
+
+        provider.cancel ();
+    }
+
+    public async PkUtils.CurrentState get_current_state () throws DBusError, IOError {
+        if (provider == null) {
+            throw new IOError.NOT_SUPPORTED ("No system update provider available");
+        }
+
+        return yield provider.get_current_state ();
+    }
+
+    public async SystemUpdateProvider.UpdateDetails get_update_details () throws DBusError, IOError {
+        if (provider == null) {
+            throw new IOError.NOT_SUPPORTED ("No system update provider available");
+        }
+
+        return yield provider.get_update_details ();
+    }
+
+    public async int64 get_last_refresh_time () throws DBusError, IOError {
+        if (provider == null) {
+            throw new IOError.NOT_SUPPORTED ("No system update provider available");
+        }
+
+        return yield provider.get_last_refresh_time ();
+    }
+}

src/Backends/SystemUpdate/SystemUpdateProvider.vala

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2023 elementary, Inc. (https://elementary.io)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * Authored by: Leonhard Kargl <leo.kargl@proton.me>
+ */
+
+public interface SettingsDaemon.Backends.SystemUpdateProvider : Object {
+    public struct UpdateDetails {
+        string[] packages;
+        uint64 size;
+        Pk.Info[] info;
+    }
+
+    public signal void state_changed ();
+
+    public abstract async void check_for_updates (bool force, bool notify) throws DBusError, IOError;
+    public abstract async void update () throws DBusError, IOError;
+    public abstract void cancel () throws DBusError, IOError;
+    public abstract async PkUtils.CurrentState get_current_state () throws DBusError, IOError;
+    public abstract async UpdateDetails get_update_details () throws DBusError, IOError;
+    public abstract async int64 get_last_refresh_time () throws DBusError, IOError;
+}

src/meson.build

@@ -10,7 +10,9 @@ sources = files(
     'Backends/NightLightSettings.vala',
     'Backends/PowerProfilesSync.vala',
     'Backends/PrefersColorSchemeSettings.vala',
-    'Backends/SystemUpdate.vala',
+    'Backends/SystemUpdate/PackageKit.vala',
+    'Backends/SystemUpdate/SystemUpdate.vala',
+    'Backends/SystemUpdate/SystemUpdateProvider.vala',
     'DBus/DesktopIntegration.vala',
     'DBus/ShellKeyGrabber.vala',
     'Utils/PkUtils.vala',