/*
A library to communicate a menu object set accross DBus and
track updates and maintain consistency.

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 <libxml/parser.h>
#include <libxml/tree.h>

#include "client.h"
#include "menuitem.h"
#include "menuitem-private.h"
#include "client-menuitem.h"
#include "dbusmenu-client.h"
#include "server-marshal.h"

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

/* Signals */
enum {
	LAYOUT_UPDATED,
	ROOT_CHANGED,
	NEW_MENUITEM,
	LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

typedef struct _DbusmenuClientPrivate DbusmenuClientPrivate;
struct _DbusmenuClientPrivate
{
	DbusmenuMenuitem * root;
	
	gchar * dbus_object;
	gchar * dbus_name;

	DBusGConnection * session_bus;
	DBusGProxy * menuproxy;
	DBusGProxy * propproxy;
	DBusGProxyCall * layoutcall;

	gint current_revision;
	gint my_revision;

	DBusGProxy * dbusproxy;

	GHashTable * type_handlers;
};

typedef struct _newItemPropData newItemPropData;
struct _newItemPropData
{
	DbusmenuClient * client;
	DbusmenuMenuitem * item;
	DbusmenuMenuitem * parent;
};

#define DBUSMENU_CLIENT_GET_PRIVATE(o) \
(G_TYPE_INSTANCE_GET_PRIVATE ((o), DBUSMENU_TYPE_CLIENT, DbusmenuClientPrivate))

/* GObject Stuff */
static void dbusmenu_client_class_init (DbusmenuClientClass *klass);
static void dbusmenu_client_init       (DbusmenuClient *self);
static void dbusmenu_client_dispose    (GObject *object);
static void dbusmenu_client_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);
/* Private Funcs */
static void layout_update (DBusGProxy * proxy, guint revision, gint parent, DbusmenuClient * client);
static void id_prop_update (DBusGProxy * proxy, gint id, gchar * property, GValue * value, DbusmenuClient * client);
static void id_update (DBusGProxy * proxy, gint id, DbusmenuClient * client);
static void build_proxies (DbusmenuClient * client);
static gint parse_node_get_id (xmlNodePtr node);
static DbusmenuMenuitem * parse_layout_xml(DbusmenuClient * client, xmlNodePtr node, DbusmenuMenuitem * item, DbusmenuMenuitem * parent, DBusGProxy * proxy);
static gint parse_layout (DbusmenuClient * client, const gchar * layout);
static void update_layout_cb (DBusGProxy * proxy, guint rev, gchar * xml, GError * in_error, void * data);
static void update_layout (DbusmenuClient * client);
static void menuitem_get_properties_cb (DBusGProxy * proxy, GHashTable * properties, GError * error, gpointer data);

/* Build a type */
G_DEFINE_TYPE (DbusmenuClient, dbusmenu_client, G_TYPE_OBJECT);

static void
dbusmenu_client_class_init (DbusmenuClientClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);

	g_type_class_add_private (klass, sizeof (DbusmenuClientPrivate));

	object_class->dispose = dbusmenu_client_dispose;
	object_class->finalize = dbusmenu_client_finalize;
	object_class->set_property = set_property;
	object_class->get_property = get_property;

	/**
		DbusmenuClient::layout-update:
		@arg0: The #DbusmenuClient object

		Tells that the layout has been updated and parsed by
		this object and is ready for grabbing by the calling
		application.
	*/
	signals[LAYOUT_UPDATED]  = g_signal_new(DBUSMENU_CLIENT_SIGNAL_LAYOUT_UPDATED,
	                                        G_TYPE_FROM_CLASS (klass),
	                                        G_SIGNAL_RUN_LAST,
	                                        G_STRUCT_OFFSET (DbusmenuClientClass, layout_updated),
	                                        NULL, NULL,
	                                        g_cclosure_marshal_VOID__VOID,
	                                        G_TYPE_NONE, 0, G_TYPE_NONE);
	/**
		DbusmenuClient::root-changed:
		@arg0: The #DbusmenuClient object
		@arg1: The new root #DbusmenuMenuitem

		The layout has changed in a way that can not be
		represented by the individual items changing as the
		root of this client has changed.
	*/
	signals[ROOT_CHANGED]    = g_signal_new(DBUSMENU_CLIENT_SIGNAL_ROOT_CHANGED,
	                                        G_TYPE_FROM_CLASS (klass),
	                                        G_SIGNAL_RUN_LAST,
	                                        G_STRUCT_OFFSET (DbusmenuClientClass, root_changed),
	                                        NULL, NULL,
	                                        g_cclosure_marshal_VOID__OBJECT,
	                                        G_TYPE_NONE, 1, G_TYPE_OBJECT);
	/**
		DbusmenuClient::new-menuitem:
		@arg0: The #DbusmenuClient object
		@arg1: The new #DbusmenuMenuitem created

		Signaled when the client creates a new menuitem.  This
		doesn't mean that it's placed anywhere.  The parent that
		it's applied to will signal #DbusmenuMenuitem::child-added
		when it gets parented.
	*/
	signals[NEW_MENUITEM]    = g_signal_new(DBUSMENU_CLIENT_SIGNAL_NEW_MENUITEM,
	                                        G_TYPE_FROM_CLASS (klass),
	                                        G_SIGNAL_RUN_LAST,
	                                        G_STRUCT_OFFSET (DbusmenuClientClass, new_menuitem),
	                                        NULL, NULL,
	                                        g_cclosure_marshal_VOID__OBJECT,
	                                        G_TYPE_NONE, 1, G_TYPE_OBJECT);

	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
dbusmenu_client_init (DbusmenuClient *self)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(self);

	priv->root = NULL;

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

	priv->session_bus = NULL;
	priv->menuproxy = NULL;
	priv->propproxy = NULL;
	priv->layoutcall = NULL;

	priv->current_revision = 0;
	priv->my_revision = 0;

	priv->dbusproxy = NULL;

	priv->type_handlers = g_hash_table_new_full(g_str_hash, g_str_equal,
	                                            g_free, NULL);

	return;
}

static void
dbusmenu_client_dispose (GObject *object)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(object);

	if (priv->layoutcall != NULL) {
		dbus_g_proxy_cancel_call(priv->menuproxy, priv->layoutcall);
		priv->layoutcall = NULL;
	}
	if (priv->menuproxy != NULL) {
		g_object_unref(G_OBJECT(priv->menuproxy));
		priv->menuproxy = NULL;
	}
	if (priv->propproxy != NULL) {
		g_object_unref(G_OBJECT(priv->propproxy));
		priv->propproxy = NULL;
	}
	if (priv->dbusproxy != NULL) {
		g_object_unref(G_OBJECT(priv->dbusproxy));
		priv->dbusproxy = NULL;
	}
	priv->session_bus = NULL;

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

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

static void
dbusmenu_client_finalize (GObject *object)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(object);

	g_free(priv->dbus_name);
	g_free(priv->dbus_object);

	if (priv->type_handlers != NULL) {
		g_hash_table_destroy(priv->type_handlers);
	}

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

static void
set_property (GObject * obj, guint id, const GValue * value, GParamSpec * pspec)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_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_proxies(DBUSMENU_CLIENT(obj));
		}
		break;
	case PROP_DBUSOBJECT:
		priv->dbus_object = g_value_dup_string(value);
		if (priv->dbus_name != NULL && priv->dbus_object != NULL) {
			build_proxies(DBUSMENU_CLIENT(obj));
		}
		break;
	default:
		g_warning("Unknown property %d.", id);
		return;
	}

	return;
}

static void
get_property (GObject * obj, guint id, GValue * value, GParamSpec * pspec)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_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 funcs */

/* Annoying little wrapper to make the right function update */
static void
layout_update (DBusGProxy * proxy, guint revision, gint parent, DbusmenuClient * client)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
	priv->current_revision = revision;
	if (priv->current_revision > priv->my_revision) {
		update_layout(client);
	}
	return;
}

/* Signal from the server that a property has changed
   on one of our menuitems */
static void
id_prop_update (DBusGProxy * proxy, gint id, gchar * property, GValue * value, DbusmenuClient * client)
{
	#ifdef MASSIVEDEBUGGING
	GValue valstr = {0};
	g_value_init(&valstr, G_TYPE_STRING);
	g_value_transform(value, &valstr);
	g_debug("Property change sent to client for item %d property %s value %s", id, property, g_utf8_strlen(g_value_get_string(&valstr), 50) < 25 ? g_value_get_string(&valstr) : "<too long>");
	g_value_unset(&valstr);
	#endif

	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);

	g_return_if_fail(priv->root != NULL);

	DbusmenuMenuitem * menuitem = dbusmenu_menuitem_find_id(priv->root, id);
	if (menuitem == NULL) {
		#ifdef MASSIVEDEBUGGING
		g_debug("Property update '%s' on id %d which couldn't be found", property, id);
		#endif
		return;
	}

	dbusmenu_menuitem_property_set_value(menuitem, property, value);

	return;
}

/* Oh, lots of updates now.  That silly server, they want
   to change all kinds of stuff! */
static void
id_update (DBusGProxy * proxy, gint id, DbusmenuClient * client)
{
	#ifdef MASSIVEDEBUGGING
	g_debug("Client side ID update: %d", id);
	#endif 

	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
	g_return_if_fail(priv->root != NULL);

	DbusmenuMenuitem * menuitem = dbusmenu_menuitem_find_id(priv->root, id);
	g_return_if_fail(menuitem != NULL);

	gchar * properties[1] = {NULL}; /* This gets them all */
	g_debug("Getting properties");
	org_ayatana_dbusmenu_get_properties_async(proxy, id, (const gchar **)properties, menuitem_get_properties_cb, menuitem);
	return;
}

/* Watches to see if our DBus savior comes onto the bus */
static void
dbus_owner_change (DBusGProxy * proxy, const gchar * name, const gchar * prev, const gchar * new, DbusmenuClient * client)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
	/* g_debug("Owner change: %s %s %s", name, prev, new); */

	if (!(new[0] != '\0' && prev[0] == '\0')) {
		/* If it's not someone new getting on the bus, sorry we
		   simply just don't care.  It's not that your service isn't
		   important to someone, just not us.  You'll find the right
		   process someday, there's lots of processes out there. */
		return;
	}

	if (g_strcmp0(name, priv->dbus_name)) {
		/* Again, someone else's service. */
		return;
	}

	/* Woot!  A service for us to love and to hold for ever
	   and ever and ever! */
	return build_proxies(client);
}

/* This function builds the DBus proxy which will look out for
   the service coming up. */
static void
build_dbus_proxy (DbusmenuClient * client)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
	GError * error = NULL;

	if (priv->dbusproxy != NULL) {
		return;
	}

	priv->dbusproxy = dbus_g_proxy_new_for_name_owner (priv->session_bus,
	                                                   DBUS_SERVICE_DBUS,
	                                                   DBUS_PATH_DBUS,
	                                                   DBUS_INTERFACE_DBUS,
	                                                   &error);
	if (error != NULL) {
		g_debug("Oh, that's bad.  That's really bad.  We can't get a proxy to DBus itself?  Seriously?  Here's all I know: %s", error->message);
		g_error_free(error);
		return;
	}

	dbus_g_proxy_add_signal(priv->dbusproxy, "NameOwnerChanged",
	                        G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
	                        G_TYPE_INVALID);
	dbus_g_proxy_connect_signal(priv->dbusproxy, "NameOwnerChanged",
	                            G_CALLBACK(dbus_owner_change), client, NULL);

	return;
}

/* A signal handler that gets called when a proxy is destoryed a
   so it needs to clean up a little.  Make sure we don't think we
   have a layout and setup the dbus watcher. */
static void
proxy_destroyed (GObject * gobj_proxy, gpointer userdata)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(userdata);

	if (priv->root != NULL) {
		g_object_unref(G_OBJECT(priv->root));
		priv->root = NULL;
		#ifdef MASSIVEDEBUGGING
		g_debug("Proxies destroyed, signaling a root change and a layout update.");
		#endif
		g_signal_emit(G_OBJECT(userdata), signals[ROOT_CHANGED], 0, NULL, TRUE);
		g_signal_emit(G_OBJECT(userdata), signals[LAYOUT_UPDATED], 0, TRUE);
	}

	if ((gpointer)priv->menuproxy == (gpointer)gobj_proxy) {
		priv->layoutcall = NULL;
	}

	priv->current_revision = 0;
	priv->my_revision = 0;

	build_dbus_proxy(DBUSMENU_CLIENT(userdata));
	return;
}

/* When we have a name and an object, build the two proxies and get the
   first version of the layout */
static void
build_proxies (DbusmenuClient * client)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
	GError * error = NULL;

	g_return_if_fail(priv->dbus_object != NULL);
	g_return_if_fail(priv->dbus_name != NULL);

	priv->session_bus = dbus_g_bus_get(DBUS_BUS_SESSION, &error);
	if (error != NULL) {
		g_error("Unable to get session bus: %s", error->message);
		g_error_free(error);
		build_dbus_proxy(client);
		return;
	}

	priv->propproxy = dbus_g_proxy_new_for_name_owner(priv->session_bus,
	                                                  priv->dbus_name,
	                                                  priv->dbus_object,
	                                                  DBUS_INTERFACE_PROPERTIES,
	                                                  &error);
	if (error != NULL) {
		g_warning("Unable to get property proxy for %s on %s: %s", priv->dbus_name, priv->dbus_object, error->message);
		g_error_free(error);
		build_dbus_proxy(client);
		return;
	}
	g_object_add_weak_pointer(G_OBJECT(priv->propproxy), (gpointer *)&priv->propproxy);
	g_signal_connect(G_OBJECT(priv->propproxy), "destroy", G_CALLBACK(proxy_destroyed), client);

	priv->menuproxy = dbus_g_proxy_new_for_name_owner(priv->session_bus,
	                                                  priv->dbus_name,
	                                                  priv->dbus_object,
	                                                  "org.ayatana.dbusmenu",
	                                                  &error);
	if (error != NULL) {
		g_warning("Unable to get dbusmenu proxy for %s on %s: %s", priv->dbus_name, priv->dbus_object, error->message);
		g_error_free(error);
		build_dbus_proxy(client);
		return;
	}
	g_object_add_weak_pointer(G_OBJECT(priv->menuproxy), (gpointer *)&priv->menuproxy);
	g_signal_connect(G_OBJECT(priv->menuproxy), "destroy", G_CALLBACK(proxy_destroyed), client);

	/* If we get here, we don't need the DBus proxy */
	if (priv->dbusproxy != NULL) {
		g_object_unref(G_OBJECT(priv->dbusproxy));
		priv->dbusproxy = NULL;
	}

	dbus_g_object_register_marshaller(_dbusmenu_server_marshal_VOID__UINT_INT, G_TYPE_NONE, G_TYPE_UINT, G_TYPE_INT, G_TYPE_INVALID);
	dbus_g_proxy_add_signal(priv->menuproxy, "LayoutUpdated", G_TYPE_UINT, G_TYPE_INT, G_TYPE_INVALID);
	dbus_g_proxy_connect_signal(priv->menuproxy, "LayoutUpdated", G_CALLBACK(layout_update), client, NULL);

	dbus_g_object_register_marshaller(_dbusmenu_server_marshal_VOID__INT_STRING_POINTER, G_TYPE_NONE, G_TYPE_INT, G_TYPE_STRING, G_TYPE_VALUE, G_TYPE_INVALID);
	dbus_g_proxy_add_signal(priv->menuproxy, "ItemPropertyUpdated", G_TYPE_INT, G_TYPE_STRING, G_TYPE_VALUE, G_TYPE_INVALID);
	dbus_g_proxy_connect_signal(priv->menuproxy, "ItemPropertyUpdated", G_CALLBACK(id_prop_update), client, NULL);

	dbus_g_proxy_add_signal(priv->menuproxy, "ItemUpdated", G_TYPE_INT, G_TYPE_INVALID);
	dbus_g_proxy_connect_signal(priv->menuproxy, "ItemUpdated", G_CALLBACK(id_update), client, NULL);

	update_layout(client);

	return;
}

/* Get the ID attribute of the node, parse it and
   return it.  Also we're checking to ensure the node
   is a 'menu' here. */
static gint
parse_node_get_id (xmlNodePtr node)
{
	if (g_strcmp0((gchar *)node->name, "menu") != 0) {
		/* This kills some nodes early */
		g_warning("XML Node is not 'menu' it is '%s'", node->name);
		return -1;
	}

	xmlAttrPtr attrib;
	for (attrib = node->properties; attrib != NULL; attrib = attrib->next) {
		if (g_strcmp0((gchar *)attrib->name, "id") == 0) {
			if (attrib->children != NULL) {
				gint id = (guint)g_ascii_strtoll((gchar *)attrib->children->content, NULL, 10);
				/* g_debug ("Found ID: %d", id); */
				return id;
			}
			break;
		}
	}

	g_warning("Unable to find an ID on the node");
	return -1;
}

/* A small helper that calls _property_set on each hash table
   entry in the properties hash. */
static void
get_properties_helper (gpointer key, gpointer value, gpointer data)
{
	dbusmenu_menuitem_property_set_value((DbusmenuMenuitem *)data, (gchar *)key, (GValue *)value);
	return;
}

/* This is the callback for the properties on a menu item.  There
   should be all of them in the Hash, and they we use foreach to
   copy them into the menuitem.
   This isn't the most efficient way.  We can optimize this by
   somehow removing the foreach.  But that is for later.  */
static void
menuitem_get_properties_cb (DBusGProxy * proxy, GHashTable * properties, GError * error, gpointer data)
{
	g_return_if_fail(DBUSMENU_IS_MENUITEM(data));
	if (error != NULL) {
		g_warning("Error getting properties on a menuitem: %s", error->message);
		return;
	}
	g_hash_table_foreach(properties, get_properties_helper, data);
	g_hash_table_destroy(properties);
	return;
}

/* This function is called to refresh the properites on an item that
   is getting recycled with the update, but we think might have prop
   changes. */
static void
menuitem_get_properties_replace_cb (DBusGProxy * proxy, GHashTable * properties, GError * error, gpointer data)
{
	g_return_if_fail(DBUSMENU_IS_MENUITEM(data));
	gboolean have_error = FALSE;

	if (error != NULL) {
		g_warning("Unable to replace properties on %d: %s", dbusmenu_menuitem_get_id(DBUSMENU_MENUITEM(data)), error->message);
		have_error = TRUE;
	}

	GList * current_props = NULL;

	for (current_props = dbusmenu_menuitem_properties_list(DBUSMENU_MENUITEM(data));
			current_props != NULL ; current_props = g_list_next(current_props)) {
		if (have_error || g_hash_table_lookup(properties, current_props->data) == NULL) {
			dbusmenu_menuitem_property_remove(DBUSMENU_MENUITEM(data), (const gchar *)current_props->data);
		}
	}

	if (!have_error) {
		menuitem_get_properties_cb(proxy, properties, error, data);
	}

	return;
}

/* This is a different get properites call back that also sends
   new signals.  It basically is a small wrapper around the original. */
static void
menuitem_get_properties_new_cb (DBusGProxy * proxy, GHashTable * properties, GError * error, gpointer data)
{
	if (error != NULL) {
		g_warning("Error getting properties on a new menuitem: %s", error->message);
		return;
	}
	g_return_if_fail(data != NULL);

	newItemPropData * propdata = (newItemPropData *)data;
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(propdata->client);

	menuitem_get_properties_cb (proxy, properties, error, propdata->item);

	gboolean handled = FALSE;

	const gchar * type;
	DbusmenuClientTypeHandler newfunc = NULL;
	
	type = dbusmenu_menuitem_property_get(propdata->item, DBUSMENU_MENUITEM_PROP_TYPE);
	if (type != NULL) {
		newfunc = g_hash_table_lookup(priv->type_handlers, type);
	} else {
		newfunc = g_hash_table_lookup(priv->type_handlers, DBUSMENU_CLIENT_TYPES_DEFAULT);
	}

	if (newfunc != NULL) {
		handled = newfunc(propdata->item, propdata->parent, propdata->client);
	}

	#ifdef MASSIVEDEBUGGING
	g_debug("Client has realized a menuitem: %d", dbusmenu_menuitem_get_id(propdata->item));
	#endif
	dbusmenu_menuitem_set_realized(propdata->item);

	if (!handled) {
		g_signal_emit(G_OBJECT(propdata->client), signals[NEW_MENUITEM], 0, propdata->item, TRUE);
	}

	g_free(propdata);

	return;
}

/* Respond to the call function to make sure that the other side
   got it, or print a warning. */
static void
menuitem_call_cb (DBusGProxy * proxy, GError * error, gpointer userdata)
{
	if (error != NULL) {
		g_warning("Unable to call menu item %d: %s", GPOINTER_TO_INT(userdata), error->message);
	}

	return;
}

/* Sends the event over DBus to the server on the other side
   of the bus. */
void
dbusmenu_client_send_event (DbusmenuClient * client, gint id, const gchar * name, const GValue * value, guint timestamp)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
	org_ayatana_dbusmenu_event_async (priv->menuproxy, id, name, value, timestamp, menuitem_call_cb, GINT_TO_POINTER(id));
	return;
}

typedef struct _about_to_show_t about_to_show_t;
struct _about_to_show_t {
	DbusmenuClient * client;
	void (*cb) (gpointer data);
	gpointer cb_data;
};

/* Reports errors and responds to update request that were a result
   of sending the about to show signal. */
static void
about_to_show_cb (DBusGProxy * proxy, gboolean need_update, GError * error, gpointer userdata)
{
	about_to_show_t * data = (about_to_show_t *)userdata;

	if (error != NULL) {
		g_warning("Unable to send about_to_show: %s", error->message);
		/* Note: we're just ensuring only the callback gets called */
		need_update = FALSE;
	}

	/* If we need to update, do that first. */
	if (need_update) {
		update_layout(data->client);
	}

	if (data->cb != NULL) {
		data->cb(data->cb_data);
	}

	g_object_unref(data->client);
	g_free(data);

	return;
}

/* Sends the about to show signal for a given id to the
   server on the other side of DBus */
void
dbusmenu_client_send_about_to_show(DbusmenuClient * client, gint id, void (*cb)(gpointer data), gpointer cb_data)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);

	about_to_show_t * data = g_new0(about_to_show_t, 1);
	data->client = client;
	data->cb = cb;
	data->cb_data = cb_data;
	g_object_ref(client);

	org_ayatana_dbusmenu_about_to_show_async (priv->menuproxy, id, about_to_show_cb, data);
	return;
}

/* Parse recursively through the XML and make it into
   objects as need be */
static DbusmenuMenuitem *
parse_layout_xml(DbusmenuClient * client, xmlNodePtr node, DbusmenuMenuitem * item, DbusmenuMenuitem * parent, DBusGProxy * proxy)
{
	gint id = parse_node_get_id(node);
	if (id < 0) {
		return NULL;
	}
	#ifdef MASSIVEDEBUGGING
	g_debug("Client looking at node with id: %d", id);
	#endif
	/* If we don't have any item, or the IDs don't match */
	if (item == NULL || dbusmenu_menuitem_get_id(item) != id) {
		if (item != NULL) {
			if (parent != NULL) {
				dbusmenu_menuitem_child_delete(parent, item);
			}
			/* XXX: Should this be an unref?  Who's reffing this that it exists without a parent? */
			g_object_unref(G_OBJECT(item));
			item = NULL;
		}

		/* Build a new item */
		item = DBUSMENU_MENUITEM(dbusmenu_client_menuitem_new(id, client));
		if (parent == NULL) {
			dbusmenu_menuitem_set_root(item, TRUE);
		}

		/* Get the properties queued up for this item */
		/* Not happy about this, but I need these :( */
		newItemPropData * propdata = g_new0(newItemPropData, 1);
		if (propdata != NULL) {
			propdata->client  = client;
			propdata->item    = item;
			propdata->parent  = parent;

			gchar * properties[1] = {NULL}; /* This gets them all */
			org_ayatana_dbusmenu_get_properties_async(proxy, id, (const gchar **)properties, menuitem_get_properties_new_cb, propdata);
		} else {
			g_warning("Unable to allocate memory to get properties for menuitem.  This menuitem will never be realized.");
		}
	} else {
		/* Refresh the properties */
		/* XXX: We shouldn't need to get the properties everytime we reuse an entry */
		gchar * properties[1] = {NULL}; /* This gets them all */
		org_ayatana_dbusmenu_get_properties_async(proxy, id, (const gchar **)properties, menuitem_get_properties_replace_cb, item);
	}

	xmlNodePtr children;
	guint position;
	GList * oldchildren = g_list_copy(dbusmenu_menuitem_get_children(item));
	/* g_debug("Starting old children: %d", g_list_length(oldchildren)); */

	for (children = node->children, position = 0; children != NULL; children = children->next, position++) {
		/* g_debug("Looking at child: %d", position); */
		gint childid = parse_node_get_id(children);
		if (childid < 0) {
			continue;
		}
		DbusmenuMenuitem * childmi = NULL;

		GList * childsearch = NULL;
		for (childsearch = oldchildren; childsearch != NULL; childsearch = g_list_next(childsearch)) {
			DbusmenuMenuitem * cs_mi = DBUSMENU_MENUITEM(childsearch->data);
			if (childid == dbusmenu_menuitem_get_id(cs_mi)) {
				oldchildren = g_list_remove(oldchildren, cs_mi);
				childmi = cs_mi;
				break;
			}
		}

		DbusmenuMenuitem * newchildmi = parse_layout_xml(client, children, childmi, item, proxy);

		if (newchildmi != childmi) {
			if (childmi != NULL) {
				dbusmenu_menuitem_child_delete(item, childmi);
			}
			dbusmenu_menuitem_child_add_position(item, newchildmi, position);
			g_object_unref(newchildmi);
		} else {
			dbusmenu_menuitem_child_reorder(item, childmi, position);
		}
	}

	/* g_debug("Stopping old children: %d", g_list_length(oldchildren)); */
	GList * oldchildleft = NULL;
	for (oldchildleft = oldchildren; oldchildleft != NULL; oldchildleft = g_list_next(oldchildleft)) {
		DbusmenuMenuitem * oldmi = DBUSMENU_MENUITEM(oldchildleft->data);
		#ifdef MASSIVEDEBUGGING
		g_debug("Unref'ing menu item with layout update. ID: %d", dbusmenu_menuitem_get_id(oldmi));
		#endif
		dbusmenu_menuitem_child_delete(item, oldmi);
	}
	g_list_free(oldchildren);

	return item;
}

/* Take the layout passed to us over DBus and turn it into
   a set of beautiful objects */
static gint
parse_layout (DbusmenuClient * client, const gchar * layout)
{
	#ifdef MASSIVEDEBUGGING
	g_debug("Client Parsing a new layout");
	#endif 

	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);

	xmlDocPtr xmldoc;

	xmldoc = xmlReadMemory(layout, g_utf8_strlen(layout, 16*1024), "dbusmenu.xml", NULL, 0);

	xmlNodePtr root = xmlDocGetRootElement(xmldoc);

	DbusmenuMenuitem * oldroot = priv->root;

	priv->root = parse_layout_xml(client, root, priv->root, NULL, priv->menuproxy);
	xmlFreeDoc(xmldoc);

	if (priv->root == NULL) {
		g_warning("Unable to parse layout on client %s object %s: %s", priv->dbus_name, priv->dbus_object, layout);
	}

	if (priv->root != oldroot) {
		#ifdef MASSIVEDEBUGGING
		g_debug("Client signaling root changed.");
		#endif 

		/* If they are different, and there was an old root we must
		   clean up that old root */
		if (oldroot != NULL) {
			dbusmenu_menuitem_set_root(oldroot, FALSE);
		}

		/* If the root changed we can signal that */
		g_signal_emit(G_OBJECT(client), signals[ROOT_CHANGED], 0, priv->root, TRUE);
	}

	/* We need to unref it in this function no matter */
	if (oldroot != NULL) {
		g_object_unref(oldroot);
	}

	return 1;
}

/* When the layout property returns, here's where we take care of that. */
static void
update_layout_cb (DBusGProxy * proxy, guint rev, gchar * xml, GError * error, void * data)
{
	DbusmenuClient * client = DBUSMENU_CLIENT(data);
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);

	if (error != NULL) {
		g_warning("Getting layout failed on client %s object %s: %s", priv->dbus_name, priv->dbus_object, error->message);
		return;
	}

	if (!parse_layout(client, xml)) {
		g_warning("Unable to parse layout!");
		return;
	}

	priv->my_revision = rev;
	/* g_debug("Root is now: 0x%X", (unsigned int)priv->root); */
	priv->layoutcall = NULL;
	#ifdef MASSIVEDEBUGGING
	g_debug("Client signaling layout has changed.");
	#endif 
	g_signal_emit(G_OBJECT(client), signals[LAYOUT_UPDATED], 0, TRUE);

	/* Check to see if we got another update in the time this
	   one was issued. */
	if (priv->my_revision < priv->current_revision) {
		update_layout(client);
	}

	return;
}

/* Call the property on the server we're connected to and set it up to
   be async back to _update_layout_cb */
static void
update_layout (DbusmenuClient * client)
{
	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);

	if (priv->menuproxy == NULL) {
		return;
	}

	if (priv->layoutcall != NULL) {
		return;
	}

	priv->layoutcall = org_ayatana_dbusmenu_get_layout_async(priv->menuproxy,
	                                                         0, /* Parent is the root */
	                                                         update_layout_cb,
	                                                         client);

	return;
}

/* Public API */
/**
	dbusmenu_client_new:
	@name: The DBus name for the server to connect to
	@object: The object on the server to monitor

	This function creates a new client that connects to a specific
	server on DBus.  That server is at a specific location sharing
	a known object.  The interface is assumed by the code to be 
	the DBus menu interface.  The newly created client will start
	sending out events as it syncs up with the server.

	Return value: A brand new #DbusmenuClient
*/
DbusmenuClient *
dbusmenu_client_new (const gchar * name, const gchar * object)
{
	DbusmenuClient * self = g_object_new(DBUSMENU_TYPE_CLIENT,
	                                     DBUSMENU_CLIENT_PROP_DBUS_NAME, name,
	                                     DBUSMENU_CLIENT_PROP_DBUS_OBJECT, object,
	                                     NULL);

	return self;
}

/**
	dbusmenu_client_get_root:
	@client: The #DbusmenuClient to get the root node from

	Grabs the root node for the specified client @client.  This
	function may block.  It will block if there is currently a
	call to update the layout, it will block on that layout 
	updated and then return the newly updated layout.  Chances
	are that this update is in the queue for the mainloop as
	it would have been requested some time ago, but in theory
	it could block longer.

	Return value: A #DbusmenuMenuitem representing the root of
		menu on the server.  If there is no server or there is
		an error receiving its layout it'll return #NULL.
*/
DbusmenuMenuitem *
dbusmenu_client_get_root (DbusmenuClient * client)
{
	g_return_val_if_fail(DBUSMENU_IS_CLIENT(client), NULL);

	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);

	if (priv->propproxy == NULL) {
		return NULL;
	}

	#ifdef MASSIVEDEBUGGING
	g_debug("Client get root: %X", (guint)priv->root);
	#endif

	return priv->root;
}

/**
	dbusmenu_client_add_type_handler:
	@client: Client where we're getting types coming in
	@type: A text string that will be matched with the 'type'
	    property on incoming menu items
	@newfunc: The function that will be executed with those new
	    items when they come in.

	This function connects into the type handling of the #DbusmenuClient.
	Every new menuitem that comes in immediately gets asked for it's
	properties.  When we get those properties we check the 'type'
	property and look to see if it matches a handler that is known
	by the client.  If so, the @newfunc function is executed on that
	#DbusmenuMenuitem.  If not, then the DbusmenuClient::new-menuitem
	signal is sent.

	In the future the known types will be sent to the server so that it
	can make choices about the menu item types availble.

	Return value: If registering the new type was successful.
*/
gboolean
dbusmenu_client_add_type_handler (DbusmenuClient * client, const gchar * type, DbusmenuClientTypeHandler newfunc)
{
	g_return_val_if_fail(DBUSMENU_IS_CLIENT(client), FALSE);
	g_return_val_if_fail(type != NULL, FALSE);

	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);

	#ifdef MASSIVEDEBUGGING
	g_debug("Adding a type handler for '%s'", type);
	#endif

	if (priv->type_handlers == NULL) {
		g_warning("Type handlers hashtable not built");
		return FALSE;
	}

	gpointer value = g_hash_table_lookup(priv->type_handlers, type);
	if (value != NULL) {
		g_warning("Type '%s' already had a registered handler.", type);
		return FALSE;
	}

	g_hash_table_insert(priv->type_handlers, g_strdup(type), newfunc);
	return TRUE;
}
