/*
A library to take the object model made consistent by libdbusmenu-glib
and visualize it in GTK.

Copyright 2009 Canonical Ltd.

Authors:
    Ted Gould <ted@canonical.com>

This program is free software: you can redistribute it and/or modify it 
under the terms of either or both of the following licenses:

1) the GNU Lesser General Public License version 3, as published by the 
Free Software Foundation; and/or
2) the GNU Lesser General Public License version 2.1, as published by 
the Free Software Foundation.

This program is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranties of 
MERCHANTABILITY, SATISFACTORY QUALITY or FITNESS FOR A PARTICULAR 
PURPOSE.  See the applicable version of the GNU Lesser General Public 
License for more details.

You should have received a copy of both the GNU Lesser General Public 
License version 3 and version 2.1 along with this program.  If not, see 
<http://www.gnu.org/licenses/>
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gtk/gtk.h>

#include "menu.h"
#include "libdbusmenu-glib/client.h"
#include "client.h"

/* Properties */
enum {
	PROP_0,
	PROP_DBUSOBJECT,
	PROP_DBUSNAME
};

/* Private */
struct _DbusmenuGtkMenuPrivate {
	DbusmenuGtkClient * client;
	DbusmenuMenuitem * root;

	gchar * dbus_object;
	gchar * dbus_name;
};

#define DBUSMENU_GTKMENU_GET_PRIVATE(o)  (DBUSMENU_GTKMENU(o)->priv)

/* Prototypes */
static void dbusmenu_gtkmenu_class_init (DbusmenuGtkMenuClass *klass);
static void dbusmenu_gtkmenu_init       (DbusmenuGtkMenu *self);
static void dbusmenu_gtkmenu_dispose    (GObject *object);
static void dbusmenu_gtkmenu_finalize   (GObject *object);
static void set_property (GObject * obj, guint id, const GValue * value, GParamSpec * pspec);
static void get_property (GObject * obj, guint id, GValue * value, GParamSpec * pspec);
/* Internal */
static void build_client (DbusmenuGtkMenu * self);
static void child_realized (DbusmenuMenuitem * child, gpointer userdata);
static void remove_child_signals (gpointer data, gpointer user_data);
static void root_changed (DbusmenuGtkClient * client, DbusmenuMenuitem * newroot, DbusmenuGtkMenu * menu);

/* GObject Stuff */
G_DEFINE_TYPE (DbusmenuGtkMenu, dbusmenu_gtkmenu, GTK_TYPE_MENU);

static void
dbusmenu_gtkmenu_class_init (DbusmenuGtkMenuClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);

	g_type_class_add_private (klass, sizeof (DbusmenuGtkMenuPrivate));

	object_class->dispose = dbusmenu_gtkmenu_dispose;
	object_class->finalize = dbusmenu_gtkmenu_finalize;
	object_class->set_property = set_property;
	object_class->get_property = get_property;

	g_object_class_install_property (object_class, PROP_DBUSOBJECT,
	                                 g_param_spec_string(DBUSMENU_CLIENT_PROP_DBUS_OBJECT, "DBus Object we represent",
	                                              "The Object on the client that we're getting our data from.",
	                                              NULL,
	                                              G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
	g_object_class_install_property (object_class, PROP_DBUSNAME,
	                                 g_param_spec_string(DBUSMENU_CLIENT_PROP_DBUS_NAME, "DBus Client we connect to",
	                                              "Name of the DBus client we're connecting to.",
	                                              NULL,
	                                              G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));

	return;
}

static void
menu_focus_cb(DbusmenuGtkMenu * menu, gpointer userdata)
{
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(menu);
	if (priv->client != NULL) {
		/* TODO: We should stop the display of the menu
		         until the about to show call returns. */
		dbusmenu_menuitem_send_about_to_show(priv->root, NULL, NULL);
	}
	return;
}

static void
dbusmenu_gtkmenu_init (DbusmenuGtkMenu *self)
{
	self->priv = G_TYPE_INSTANCE_GET_PRIVATE ((self), DBUSMENU_GTKMENU_TYPE, DbusmenuGtkMenuPrivate);

	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(self);

	priv->client = NULL;

	priv->dbus_object = NULL;
	priv->dbus_name = NULL;

	g_signal_connect(G_OBJECT(self), "focus", G_CALLBACK(menu_focus_cb), self);

	return;
}

static void
dbusmenu_gtkmenu_dispose (GObject *object)
{
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(object);

	/* Remove signals from the root */
	if (priv->root != NULL) {
		/* This will clear the root */
		root_changed(priv->client, NULL, DBUSMENU_GTKMENU(object));
	}

	if (priv->client != NULL) {
		g_object_unref(G_OBJECT(priv->client));
		priv->client = NULL;
	}

	G_OBJECT_CLASS (dbusmenu_gtkmenu_parent_class)->dispose (object);
	return;
}

static void
dbusmenu_gtkmenu_finalize (GObject *object)
{
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(object);

	g_free(priv->dbus_object);
	priv->dbus_object = NULL;

	g_free(priv->dbus_name);
	priv->dbus_name = NULL;

	G_OBJECT_CLASS (dbusmenu_gtkmenu_parent_class)->finalize (object);
	return;
}

static void
set_property (GObject * obj, guint id, const GValue * value, GParamSpec * pspec)
{
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(obj);

	switch (id) {
	case PROP_DBUSNAME:
		priv->dbus_name = g_value_dup_string(value);
		if (priv->dbus_name != NULL && priv->dbus_object != NULL) {
			build_client(DBUSMENU_GTKMENU(obj));
		}
		break;
	case PROP_DBUSOBJECT:
		priv->dbus_object = g_value_dup_string(value);
		if (priv->dbus_name != NULL && priv->dbus_object != NULL) {
			build_client(DBUSMENU_GTKMENU(obj));
		}
		break;
	default:
		g_warning("Unknown property %d.", id);
		return;
	}

	return;
}

static void
get_property (GObject * obj, guint id, GValue * value, GParamSpec * pspec)
{
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(obj);

	switch (id) {
	case PROP_DBUSNAME:
		g_value_set_string(value, priv->dbus_name);
		break;
	case PROP_DBUSOBJECT:
		g_value_set_string(value, priv->dbus_object);
		break;
	default:
		g_warning("Unknown property %d.", id);
		return;
	}

	return;
}

/* Internal Functions */

#ifdef MASSIVEDEBUGGING
typedef struct {
	GtkMenuItem * mi;
	gint finalpos;
	gboolean found;
} menu_pos_t;

static void
find_pos (GtkWidget * widget, gpointer data)
{
	menu_pos_t * menu_pos = (menu_pos_t *)data;
	if (menu_pos->found) return;
	if ((gpointer)(menu_pos->mi) == (gpointer)widget) {
		menu_pos->found = TRUE;
	} else {
		menu_pos->finalpos++;
	}
	return;
}
#endif


/* Called when a new child of the root item is
   added.  Sets up a signal for when it's actually
   realized. */
static void
root_child_added (DbusmenuMenuitem * root, DbusmenuMenuitem * child, guint position, DbusmenuGtkMenu * menu)
{
	#ifdef MASSIVEDEBUGGING
	g_debug("Root new child");
	#endif
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(menu);

	g_signal_connect(G_OBJECT(child), DBUSMENU_MENUITEM_SIGNAL_REALIZED, G_CALLBACK(child_realized), menu);

	GtkMenuItem * mi = dbusmenu_gtkclient_menuitem_get(priv->client, child);
	if (mi != NULL) {
		GtkWidget * item = GTK_WIDGET(mi);
		gtk_menu_shell_insert(GTK_MENU_SHELL(menu), item, dbusmenu_menuitem_get_position_realized(child, root));
		#ifdef MASSIVEDEBUGGING
		menu_pos_t menu_pos;
		menu_pos.mi = mi;
		menu_pos.finalpos = 0;
		menu_pos.found = FALSE;

		gtk_container_foreach(GTK_CONTAINER(menu), find_pos, &menu_pos);
		g_debug("Menu position requested was %d but got %d", position, menu_pos.finalpos);
		#endif
	}
	return;
}

/* When one of the children move we need to react to that and
   move it on the GTK side as well. */
static void
root_child_moved (DbusmenuMenuitem * root, DbusmenuMenuitem * child, guint newposition, guint oldposition, DbusmenuGtkMenu * menu)
{
	#ifdef MASSIVEDEBUGGING
	g_debug("Root child moved");
	#endif
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(menu);
	gtk_menu_reorder_child(GTK_MENU(menu), GTK_WIDGET(dbusmenu_gtkclient_menuitem_get(priv->client, child)), dbusmenu_menuitem_get_position_realized(child, root));
	return;
}

/* When a root child item disappears. */
static void
root_child_delete (DbusmenuMenuitem * root, DbusmenuMenuitem * child, DbusmenuGtkMenu * menu)
{
	#ifdef MASSIVEDEBUGGING
	g_debug("Root child deleted");
	#endif

	/* Remove signal for realized */
	remove_child_signals(child, menu);

	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(menu);
	GtkWidget * item = GTK_WIDGET(dbusmenu_gtkclient_menuitem_get(priv->client, child));
	if (item != NULL) {
		gtk_container_remove(GTK_CONTAINER(menu), item);
	}

	if (g_list_length(dbusmenu_menuitem_get_children(root)) == 0) {
		gtk_widget_hide(GTK_WIDGET(menu));
	}
	return;
}

/* Called when the child is realized, and thus has all of its
   properties and GTK-isms.  We can put it in our menu here. */
static void
child_realized (DbusmenuMenuitem * child, gpointer userdata)
{
	#ifdef MASSIVEDEBUGGING
	g_debug("Root child realized");
	#endif
	g_return_if_fail(DBUSMENU_IS_GTKMENU(userdata));

	DbusmenuGtkMenu * menu = DBUSMENU_GTKMENU(userdata);
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(menu);

	GtkWidget * child_widget = GTK_WIDGET(dbusmenu_gtkclient_menuitem_get(priv->client, child));

	if (child_widget != NULL) {
		gtk_menu_shell_append(GTK_MENU_SHELL(menu), child_widget);
		gtk_menu_reorder_child(GTK_MENU(menu), child_widget, dbusmenu_menuitem_get_position_realized(child, dbusmenu_client_get_root(DBUSMENU_CLIENT(priv->client))));
	} else {
		g_warning("Child is realized, but doesn't have a GTK Widget!");
	}

	return;
}

/* Remove any signals we attached to children -- just realized right now */
static void
remove_child_signals (gpointer data, gpointer user_data)
{
	g_signal_handlers_disconnect_by_func(G_OBJECT(data), child_realized, user_data);
	return;
}

/* Handler for all of the menu items on a root change to ensure that
   the menus are hidden before we start going and deleting things. */
static void
popdown_all (DbusmenuMenuitem * mi, gpointer user_data)
{
	GtkMenu * menu = dbusmenu_gtkclient_menuitem_get_submenu(DBUSMENU_GTKCLIENT(user_data), mi);
	if (menu != NULL) {
		gtk_menu_popdown(menu);
	}
	return;
}

/* When the root menuitem changes we need to resetup things so that
   we're back in the game. */
static void
root_changed (DbusmenuGtkClient * client, DbusmenuMenuitem * newroot, DbusmenuGtkMenu * menu) {
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(menu);

	/* Clear out our interest in the old root */
	if (priv->root != NULL) {
		GList * children = dbusmenu_menuitem_get_children(priv->root);
		g_list_foreach(children, remove_child_signals, menu);

		g_signal_handlers_disconnect_by_func(G_OBJECT(priv->root), root_child_added, menu);
		g_signal_handlers_disconnect_by_func(G_OBJECT(priv->root), root_child_moved, menu);
		g_signal_handlers_disconnect_by_func(G_OBJECT(priv->root), root_child_delete, menu);

		dbusmenu_menuitem_foreach(priv->root, popdown_all, client);

		g_object_unref(priv->root);
		priv->root = NULL;
	}

	if (newroot == NULL) {
		gtk_widget_hide(GTK_WIDGET(menu));
		return;
	}

	priv->root = newroot;
	g_object_ref(priv->root);

	g_signal_connect(G_OBJECT(newroot), DBUSMENU_MENUITEM_SIGNAL_CHILD_ADDED,   G_CALLBACK(root_child_added),  menu);
	g_signal_connect(G_OBJECT(newroot), DBUSMENU_MENUITEM_SIGNAL_CHILD_MOVED,   G_CALLBACK(root_child_moved),  menu);
	g_signal_connect(G_OBJECT(newroot), DBUSMENU_MENUITEM_SIGNAL_CHILD_REMOVED, G_CALLBACK(root_child_delete), menu);

	GList * child = NULL;
	guint count = 0;
	for (child = dbusmenu_menuitem_get_children(newroot); child != NULL; child = g_list_next(child)) {
		/* gtk_menu_append(menu, GTK_WIDGET(dbusmenu_gtkclient_menuitem_get(client, child->data))); */
		g_signal_connect(G_OBJECT(child->data), DBUSMENU_MENUITEM_SIGNAL_REALIZED, G_CALLBACK(child_realized), menu);
		count++;
	}

	if (count > 0) {
		gtk_widget_show(GTK_WIDGET(menu));
	} else {
		gtk_widget_hide(GTK_WIDGET(menu));
	}

	return;
}

/* Builds the client and connects all of the signals
   up for it so that it's happy-happy */
static void
build_client (DbusmenuGtkMenu * self)
{
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(self);

	if (priv->client == NULL) {
		priv->client = dbusmenu_gtkclient_new(priv->dbus_name, priv->dbus_object);

		/* Register for layout changes, this should come after the
		   creation of the client pulls it from DBus */
		g_signal_connect(G_OBJECT(priv->client), DBUSMENU_GTKCLIENT_SIGNAL_ROOT_CHANGED, G_CALLBACK(root_changed), self);
	}

	return;
}

/* Public API */

/**
 * dbusmenu_gtkmenu_new:
 * @dbus_name: Name of the #DbusmenuServer on DBus
 * @dbus_object: Name of the object on the #DbusmenuServer
 * 
 * Creates a new #DbusmenuGtkMenu object and creates a #DbusmenuClient
 * that connects across DBus to a #DbusmenuServer.
 * 
 * Return value: A new #DbusmenuGtkMenu sync'd with a server
 */
DbusmenuGtkMenu *
dbusmenu_gtkmenu_new (gchar * dbus_name, gchar * dbus_object)
{
	return g_object_new(DBUSMENU_GTKMENU_TYPE,
	                    DBUSMENU_CLIENT_PROP_DBUS_OBJECT, dbus_object,
	                    DBUSMENU_CLIENT_PROP_DBUS_NAME, dbus_name,
	                    NULL);
}

/**
 * dbusmenu_gtkmenu_get_client:
 * @menu: The #DbusmenuGtkMenu to get the client from
 * 
 * An accessor for the client that this menu is using to
 * communicate with the server.
 * 
 * Return value: (transfer none): A valid #DbusmenuGtkClient or NULL on error.
 */
DbusmenuGtkClient *
dbusmenu_gtkmenu_get_client (DbusmenuGtkMenu * menu)
{
	g_return_val_if_fail(DBUSMENU_IS_GTKMENU(menu), NULL);
	DbusmenuGtkMenuPrivate * priv = DBUSMENU_GTKMENU_GET_PRIVATE(menu);
	return priv->client;
}