#include <sys/stat.h>
#include <gtk/gtk.h>

static GtkWidget *main_window = NULL;

#ifdef USE_GTK_DRAG_BEGIN
static gboolean in_drag_operation = FALSE;
static gint drag_button = 0;
static gint drag_x = 0;
static gint drag_y = 0;
#endif

#define DRAG_TEXT_URI_LIST 1
#define DRAG_TEXT_PLAIN    2

static GtkTargetEntry drag_targets[] = {
	{ "text/uri-list", 0, DRAG_TEXT_URI_LIST },
	{ "text/plain", 0, DRAG_TEXT_PLAIN }
};

static void make_uri_list(gchar ***uri_list)
{
	gchar **list;
	gchar *path;
	GDir *dir;
	const gchar *name;
	struct stat sb;
	GList *files = NULL;
	GList *cur;
	gchar *tmp;
	gchar *p;

	*uri_list = NULL;

	path = g_get_current_dir();
	dir = g_dir_open(path, 0, NULL);
	if (dir == NULL) {
		g_free(path);
		return;
	}
	while ((name = g_dir_read_name(dir)) != NULL) {
		tmp = g_build_filename(path, name, NULL);

		if (g_stat(tmp, &sb) == 0
			&& (sb.st_mode & S_IFMT) == S_IFREG) {

			p = g_strrstr(name, ".");
			if (p != NULL) {
				p++;
				if (g_ascii_strcasecmp(p, "c") == 0
					|| g_ascii_strcasecmp(p, "txt") == 0
					|| g_ascii_strcasecmp(p, "htm") == 0
					|| g_ascii_strcasecmp(p, "html") == 0) {
					files = g_list_append(files, tmp);
					continue;
				}
			}
		}
		g_free(tmp);
	}
	g_dir_close(dir);
	g_free(path);

	if (g_list_length(files) > 0) {
		list = g_new0(gchar *, g_list_length(files) + 1);
		*uri_list = list;

		for (cur = g_list_first(files); cur != NULL; cur = g_list_next(cur)) {
			p = g_filename_to_uri(cur->data, NULL, NULL);
			if (p == NULL) {
				continue;
			}
			*list++ = p;
		}
	}
	*list = NULL;
	g_list_foreach(files, (GFunc)g_free, NULL);
	g_list_free(files);
}

void drag_begin(GtkWidget	*widget,
				GdkDragContext	*context,
				gpointer		user_data)
{
	g_print("<<< DRAG BEGIN >>>\n");
}

void drag_data_get(GtkWidget		*widget,
				   GdkDragContext	*context,
				   GtkSelectionData	*data,
				   guint			info,
				   guint			time_,
				   gpointer		user_data)
{
	g_print("<<< DRAG DATA GET >>>\n");

	g_print("data->target=%d %s\n", data->target, gdk_atom_name((GdkAtom)data->target));
	g_print("info=%d\n", info);

	if (info == DRAG_TEXT_URI_LIST) {
		gchar **uri_list = NULL;
		gchar **ptr;

		make_uri_list(&uri_list);
		if (uri_list != NULL) {
			gtk_selection_data_set_uris(data, uri_list);

			for (ptr = uri_list; *ptr != NULL; ptr++) {
				g_free(*ptr);
			}
			g_free(uri_list);
		}
	} else if (info == DRAG_TEXT_PLAIN) {
		const char *msg = "hello, world!";
		gtk_selection_data_set_text(data, msg, strlen(msg));
	}
}

void drag_data_delete(GtkWidget		*widget,
					  GdkDragContext	*context,
					  gpointer		user_data)
{
	g_print("<<< DRAG DATA DELETE >>>\n");
}

void drag_end(GtkWidget		*widget,
			  GdkDragContext	*context,
			  gpointer		user_data)
{
	g_print("<<< DRAG END >>>\n");

#ifdef USE_GTK_DRAG_BEGIN
	in_drag_operation = FALSE;
	drag_button = 0;
#endif
}

#ifdef USE_GTK_DRAG_BEGIN
gboolean button_press_event(GtkWidget *widget,
							GdkEventButton *event,
							gpointer user_data)
{
	g_print("<<< BUTTON PRESS EVENT >>>\n");

	if (in_drag_operation) {
		return FALSE;
	}
	if (event == NULL) {
		return FALSE;
	}
	if (event->button != 1 && event->button != 2 && event->button != 3) {
		return FALSE;
	}

	if (drag_button == 0) {
		drag_button = event->button;
		drag_x = (gint)event->x;
		drag_y = (gint)event->y;
	} else if (event->button < drag_button) {
		drag_button = event->button;
	}

	return FALSE;
}
#endif

#ifdef USE_GTK_DRAG_BEGIN
gboolean button_release_event(GtkWidget *widget,
							  GdkEventButton *event,
							  gpointer user_data)
{
	g_print("<<< BUTTON RELEASE EVENT >>>\n");

	if (in_drag_operation) {
		return FALSE;
	}
	if (event == NULL) {
		return FALSE;
	}
	if (event->button != 1 && event->button != 2 && event->button != 3) {
		return FALSE;
	}
	drag_button = 0;

	return FALSE;
}
#endif

#ifdef USE_GTK_DRAG_BEGIN
gboolean motion_notify_event(GtkWidget *widget,
							 GdkEventMotion *event,
							 gpointer user_data)
{
	g_print("<<< MOTION NOTIFY EVENT >>>\n");

	if (in_drag_operation) {
		return FALSE;
	}
	if (event == NULL) {
		return FALSE;
	}
	if (drag_button == 0) {
		return FALSE;
	}

	if (gtk_drag_check_threshold(widget,
								 drag_x,
								 drag_y,
								 (gint)event->x,
								 (gint)event->y)) {
		GtkTargetList *list;

		in_drag_operation = TRUE;
		list = gtk_target_list_new(drag_targets,sizeof(drag_targets) / sizeof(drag_targets[0]));
		gtk_drag_begin(widget,
					   list,
					   GDK_ACTION_COPY | GDK_ACTION_MOVE | GDK_ACTION_LINK | GDK_ACTION_ASK,
					   drag_button,
					   (GdkEvent *)event);
		gtk_target_list_unref(list);
	}

	return FALSE;
}
#endif

#ifdef USE_GTK_DRAG_BEGIN
gboolean leave_notify_event(GtkWidget *widget,
							GdkEventCrossing *event,
							gpointer user_data)
{
	g_print("<<< LEAVE NOTIFY EVENT >>>\n");

	if (!in_drag_operation) {
		drag_button = 0;
	}

	return FALSE;
}
#endif

int main(int argc, char **argv)
{
	GtkWidget *window;
	GtkWidget *button;

	gtk_init(&argc, &argv);

	window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	gtk_window_set_title(GTK_WINDOW(window), "dnd drag test");
	gtk_window_set_default_size(GTK_WINDOW(window), 300, 150);
	g_signal_connect(G_OBJECT(window), "destroy",
					 G_CALLBACK(gtk_main_quit), NULL);

	button = gtk_button_new_with_label("ドラッグして！");
	g_signal_connect(G_OBJECT(button), "drag-begin",
					 G_CALLBACK(drag_begin), NULL);
	g_signal_connect(G_OBJECT(button), "drag-data-get",
					 G_CALLBACK(drag_data_get), NULL);
	g_signal_connect(G_OBJECT(button), "drag-data-delete",
					 G_CALLBACK(drag_data_delete), NULL);
	g_signal_connect(G_OBJECT(button), "drag-end",
					 G_CALLBACK(drag_end), NULL);
#ifdef USE_GTK_DRAG_BEGIN
	g_signal_connect(G_OBJECT(button), "button-press-event",
					 G_CALLBACK(button_press_event), NULL);
	g_signal_connect(G_OBJECT(button), "button-release-event",
					 G_CALLBACK(button_release_event), NULL);
	g_signal_connect(G_OBJECT(button), "motion-notify-event",
					 G_CALLBACK(motion_notify_event), NULL);
	g_signal_connect(G_OBJECT(button), "leave-notify-event",
					 G_CALLBACK(leave_notify_event), NULL);
	gtk_widget_set_events(button, gtk_widget_get_events(button) | GDK_POINTER_MOTION_MASK);
#else
	gtk_drag_source_set(button,
						GDK_BUTTON1_MASK | GDK_BUTTON2_MASK | GDK_BUTTON3_MASK,
						drag_targets,
						sizeof(drag_targets) / sizeof(drag_targets[0]),
						GDK_ACTION_COPY | GDK_ACTION_MOVE | GDK_ACTION_LINK | GDK_ACTION_ASK);
#endif
	gtk_container_add(GTK_CONTAINER(window), button);
	gtk_widget_show_all(window);

	gtk_main();
	return 0;
}