//
//  Copyright (c) 2018 elementary LLC. (https://elementary.io)
//
//  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, either version 3 of the License, or
//  (at your option) any later version.
//
//  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/>.
//

namespace Gala {
    const string DBUS_NAME = "org.pantheon.gala";
    const string DBUS_OBJECT_PATH = "/org/pantheon/gala";

    const string DAEMON_DBUS_NAME = "org.pantheon.gala.daemon";
    const string DAEMON_DBUS_OBJECT_PATH = "/org/pantheon/gala/daemon";

    [DBus (name = "org.pantheon.gala")]
    public interface WMDBus : GLib.Object {
        public abstract void perform_action (Gala.ActionType type) throws DBusError, IOError;
    }

    [DBus (name = "org.pantheon.gala.daemon")]
    public class MenuDaemon : Object {
        Gtk.Menu? window_menu = null;
        Gtk.MenuItem minimize;
        Gtk.MenuItem maximize;
        Gtk.MenuItem move;
        Gtk.MenuItem resize;
        Gtk.CheckMenuItem always_on_top;
        Gtk.CheckMenuItem on_visible_workspace;
        Gtk.MenuItem move_left;
        Gtk.MenuItem move_right;
        Gtk.MenuItem close;

        WMDBus? wm_proxy = null;

        ulong always_on_top_sid = 0U;
        ulong on_visible_workspace_sid = 0U;

        [DBus (visible = false)]
        public void setup_dbus () {
            var flags = BusNameOwnerFlags.ALLOW_REPLACEMENT | BusNameOwnerFlags.REPLACE;
            Bus.own_name (BusType.SESSION, DAEMON_DBUS_NAME, flags, on_bus_acquired, () => {}, null);

            Bus.watch_name (BusType.SESSION, DBUS_NAME, BusNameWatcherFlags.NONE, gala_appeared, lost_gala);
        }

        void on_gala_get (GLib.Object? o, GLib.AsyncResult? res) {
            try {
                wm_proxy = Bus.get_proxy.end (res);
            } catch (Error e) {
                warning ("Failed to get Gala proxy: %s", e.message);
            }
        }

        void lost_gala () {
            wm_proxy = null;
        }

        void gala_appeared () {
            if (wm_proxy == null) {
                Bus.get_proxy.begin<WMDBus> (BusType.SESSION, DBUS_NAME, DBUS_OBJECT_PATH, 0, null, on_gala_get);
            }
        }

        void on_bus_acquired (DBusConnection conn) {
            try {
                conn.register_object (DAEMON_DBUS_OBJECT_PATH, this);
            } catch (Error e) {
                stderr.printf ("Error registering MenuDaemon: %s\n", e.message);
            }
        }

        void perform_action (Gala.ActionType type) {
            if (wm_proxy != null) {
                try {
                    wm_proxy.perform_action (type);
                } catch (Error e) {
                    warning ("Failed to perform Gala action over DBus: %s", e.message);
                }
            }
        }

        void init_window_menu () {
            window_menu = new Gtk.Menu ();

            minimize = new Gtk.MenuItem.with_label (_("Minimize"));
            minimize.activate.connect (() => {
                perform_action (Gala.ActionType.MINIMIZE_CURRENT);
            });
            window_menu.append (minimize);

            maximize = new Gtk.MenuItem.with_label ("");
            maximize.activate.connect (() => {
                perform_action (Gala.ActionType.MAXIMIZE_CURRENT);
            });
            window_menu.append (maximize);

            move = new Gtk.MenuItem.with_label (_("Move"));
            move.activate.connect (() => {
                perform_action (Gala.ActionType.START_MOVE_CURRENT);
            });
            window_menu.append (move);

            resize = new Gtk.MenuItem.with_label (_("Resize"));
            resize.activate.connect (() => {
                perform_action (Gala.ActionType.START_RESIZE_CURRENT);
            });
            window_menu.append (resize);

            always_on_top = new Gtk.CheckMenuItem.with_label (_("Always on Top"));
            always_on_top_sid = always_on_top.activate.connect (() => {
                perform_action (Gala.ActionType.TOGGLE_ALWAYS_ON_TOP_CURRENT);
            });
            window_menu.append (always_on_top);

            on_visible_workspace = new Gtk.CheckMenuItem.with_label (_("Always on Visible Workspace"));
            on_visible_workspace_sid = on_visible_workspace.activate.connect (() => {
                perform_action (Gala.ActionType.TOGGLE_ALWAYS_ON_VISIBLE_WORKSPACE_CURRENT);
            });
            window_menu.append (on_visible_workspace);

            move_left = new Gtk.MenuItem.with_label (_("Move to Workspace Left"));
            move_left.activate.connect (() => {
                perform_action (Gala.ActionType.MOVE_CURRENT_WORKSPACE_LEFT);
            });
            window_menu.append (move_left);

            move_right = new Gtk.MenuItem.with_label (_("Move to Workspace Right"));
            move_right.activate.connect (() => {
                perform_action (Gala.ActionType.MOVE_CURRENT_WORKSPACE_RIGHT);
            });
            window_menu.append (move_right);

            close = new Gtk.MenuItem.with_label (_("Close"));
            close.activate.connect (() => {
                perform_action (Gala.ActionType.CLOSE_CURRENT);
            });
            window_menu.append (close);

            window_menu.show_all ();
        }

        public void show_window_menu (Gala.WindowFlags flags, int x, int y) throws DBusError, IOError {
            if (window_menu == null) {
                init_window_menu ();
            }

            minimize.visible = Gala.WindowFlags.CAN_MINIMIZE in flags;
            maximize.visible = Gala.WindowFlags.CAN_MAXIMIZE in flags;
            maximize.label = Gala.WindowFlags.IS_MAXIMIZED in flags ? _("Unmaximize") : _("Maximize");
            move.visible = Gala.WindowFlags.ALLOWS_MOVE in flags;
            resize.visible = Gala.WindowFlags.ALLOWS_RESIZE in flags;

            // Setting active causes signal fires on activate so
            // we temporarily block those signals from emissions
            SignalHandler.block (always_on_top, always_on_top_sid);
            SignalHandler.block (on_visible_workspace, on_visible_workspace_sid);

            always_on_top.active = Gala.WindowFlags.ALWAYS_ON_TOP in flags;
            on_visible_workspace.active = Gala.WindowFlags.ON_ALL_WORKSPACES in flags;

            SignalHandler.unblock (always_on_top, always_on_top_sid);
            SignalHandler.unblock (on_visible_workspace, on_visible_workspace_sid);

            move_right.visible = !on_visible_workspace.active;
            move_left.visible = !on_visible_workspace.active;
            close.visible = Gala.WindowFlags.CAN_CLOSE in flags;

            window_menu.popup (null, null, (m, ref px, ref py, out push_in) => {
                var scale = m.scale_factor;
                px = x / scale;
                // Move the menu 1 pixel outside of the pointer or else it closes instantly
                // on the mouse up event
                py = (y / scale) + 1;
                push_in = true;
            }, 3, Gdk.CURRENT_TIME);
        }
    }
}