#include <gtk/gtk.h>

#include <libxfce4panel/xfce-panel-plugin.h>
#include <libxfce4panel/libxfce4panel.h>

#include <libwnck/libwnck.h>

#include <glib.h>
#include <glib-object.h>

typedef struct {
	XfcePanelPlugin *plugin;

	GtkWidget *button;
	GtkWidget *label;
	GtkWidget *menu;

	WnckScreen *screen;
	WnckWindow *window;

	gint screen_id;
	gint wnck_screen_id;
	gint wnck_window_id;
} TitlePlugin;

static void title_construct(XfcePanelPlugin *plugin);

XFCE_PANEL_PLUGIN_REGISTER(title_construct);

static void title_free(XfcePanelPlugin *plugin, TitlePlugin *title)
{
	if (title->screen_id != 0)
		g_signal_handler_disconnect(plugin, title->screen_id);

	if (title->wnck_screen_id != 0)
		g_signal_handler_disconnect(title->screen, title->wnck_screen_id);

	if (title->wnck_window_id != 0)
		g_signal_handler_disconnect(title->window, title->wnck_window_id);

	if (title->menu != NULL)
		gtk_widget_destroy(title->menu);

	title->screen_id = 0;
	title->wnck_screen_id = 0;
	title->wnck_window_id = 0;

	gtk_widget_destroy(title->button);
	panel_slice_free(TitlePlugin, title);
}

static gboolean title_size_changed(XfcePanelPlugin *plugin,
				   gint size,
				   G_GNUC_UNUSED TitlePlugin *title)
{
	GtkOrientation orientation;

	orientation = xfce_panel_plugin_get_orientation(plugin);

	if (orientation == GTK_ORIENTATION_HORIZONTAL)
		gtk_widget_set_size_request(GTK_WIDGET(plugin), -1, size);
	else
		gtk_widget_set_size_request(GTK_WIDGET(plugin), size, -1);

	return TRUE;
}

static void title_update_label(TitlePlugin *title, const char *label)
{
	gtk_label_set_label(GTK_LABEL(title->label), label);
	gtk_widget_set_tooltip_text(title->button, label);
}

static void title_window_name_changed(WnckWindow *window,
					     TitlePlugin *title)
{
	const gchar *name = wnck_window_get_name(window);
	title_update_label(title, name);
}

static int title_check_type(WnckWindow *window)
{
	WnckWindowType type = wnck_window_get_window_type(window);

	switch (type) {
	case WNCK_WINDOW_NORMAL:
	case WNCK_WINDOW_DIALOG:
		return 0;

	default:
		break;
	}

	return 1;
}

static void title_window_changed(WnckScreen *screen,
				 G_GNUC_UNUSED WnckWindow *window_,
				 TitlePlugin *title)
{
	WnckWindow *window;
	const gchar *name = NULL;

	if (title->wnck_window_id != 0) {
		g_signal_handler_disconnect(title->window, title->wnck_window_id);
		title->wnck_window_id = 0;
		title->window = NULL;
	}

	window = wnck_screen_get_active_window(screen);

	if (window == NULL || title_check_type(window))
		gtk_widget_hide(title->button);
	else {
		title->window = window;

		name = wnck_window_get_name(window);

		title->wnck_window_id = g_signal_connect(
			window, "name-changed",
			G_CALLBACK(title_window_name_changed), title
		);

		gtk_widget_show(title->button);
	}

	title_update_label(title, name);
}

static void title_screen_changed(XfcePanelPlugin *plugin,
				 GdkScreen *screen,
				 TitlePlugin *title)
{
	if (title->wnck_screen_id != 0) {
		g_signal_handler_disconnect(title->screen, title->wnck_screen_id);
		title->wnck_screen_id = 0;
	}

	if (title->wnck_window_id != 0) {
		g_signal_handler_disconnect(title->window, title->wnck_window_id);
		title->wnck_window_id = 0;
		title->window = NULL;
	}

	screen = gtk_widget_get_screen(GTK_WIDGET(plugin));
	if (screen != NULL) {
		G_GNUC_BEGIN_IGNORE_DEPRECATIONS
		title->screen = wnck_screen_get(gdk_screen_get_number(screen));
		G_GNUC_END_IGNORE_DEPRECATIONS

		title->wnck_screen_id = g_signal_connect(
			title->screen, "active-window-changed",
			G_CALLBACK(title_window_changed), title
		);

		title_window_changed(title->screen, NULL, title);
	}
}

static void title_menu_destroy(GtkWidget *menu, TitlePlugin *title)
{
	gtk_widget_destroy(menu);
	title->menu = NULL;
}

static void title_pressed(GtkButton *button, TitlePlugin *title)
{
	if (title->menu != NULL)
		gtk_widget_destroy(title->menu);

	if (title->window != NULL) {
		GtkWidget *menu = wnck_action_menu_new(title->window);

		title->menu = menu;

		g_signal_connect(G_OBJECT(menu), "selection-done", G_CALLBACK(title_menu_destroy), title);
		gtk_menu_attach_to_widget(GTK_MENU(menu), GTK_WIDGET(button), NULL);
		gtk_menu_popup_at_pointer(GTK_MENU(menu), NULL);
	}
}

static TitlePlugin *title_new(XfcePanelPlugin *plugin)
{
	TitlePlugin *title;

	title = g_slice_new0(TitlePlugin);

	title->plugin = plugin;

	title->button = xfce_create_panel_button();
	gtk_widget_show(title->button);

	title->label = gtk_label_new(NULL);
	gtk_label_set_ellipsize(GTK_LABEL(title->label), PANGO_ELLIPSIZE_END);
	gtk_widget_show(title->label);

	gtk_container_add(GTK_CONTAINER(title->button), title->label);

	return title;
}

static void title_construct(XfcePanelPlugin *plugin)
{
	TitlePlugin *title;

	title = title_new(plugin);

	gtk_container_add(GTK_CONTAINER(plugin), title->button);

	xfce_panel_plugin_add_action_widget(plugin, title->button);
	xfce_panel_plugin_set_expand(plugin, TRUE);

	g_signal_connect(plugin, "free-data",
			 G_CALLBACK(title_free), title);

	g_signal_connect(plugin, "size-changed",
			 G_CALLBACK(title_size_changed), NULL);

	g_signal_connect(title->button, "pressed",
			 G_CALLBACK(title_pressed), title);

	title_screen_changed(plugin, gtk_widget_get_screen(title->button),
			     title);

	title->screen_id = g_signal_connect(
		plugin, "screen-changed",
		G_CALLBACK(title_screen_changed), title
	);
}