#include <glib.h>
#include <glib/gstdio.h>
#include <fcntl.h>
#include <gtk/gtk.h>

#define INCLUDE_SYMBOL ((gpointer) 1)
#define ENGINE_SYMBOL ((gpointer) 2)
#define COLOR_SCHEME_SYMBOL ((gpointer) 3)

static gint
str_nequal (gchar *a, gchar *b)
{
	return !g_str_equal (a, b);
}

gchar *
gtkrc_find_named (const gchar *name)
{
	/* find the gtkrc of the named theme
	 * taken from gtkrc.c (gtk_rc_parse_named)
	 */
	gchar *path = NULL;
	const gchar *home_dir;
	gchar *subpath;
	subpath = g_strdup ("gtk-2.0" G_DIR_SEPARATOR_S "gtkrc");

	/* First look in the users home directory
	*/
	home_dir = g_get_home_dir ();
	if (home_dir)
	{
		path = g_build_filename (home_dir, ".themes", name, subpath, NULL);
		if (!g_file_test (path, G_FILE_TEST_EXISTS))
		{
			g_free (path);
			path = NULL;
		}
	}

	if (!path)
	{
		gchar *theme_dir = gtk_rc_get_theme_dir ();
		path = g_build_filename (theme_dir, name, subpath, NULL);
		g_free (theme_dir);

		if (!g_file_test (path, G_FILE_TEST_EXISTS))
		{
			g_free (path);
			path = NULL;
		}
	}

	return path;

}

void
gtkrc_get_details (gchar *filename, GSList **engines, GSList **symbolic_colors)
{
	gint file = -1;
	GSList *files = NULL;
	GSList *read_files = NULL;
	GTokenType token;
	GScanner *scanner = g_scanner_new (NULL);

	g_scanner_scope_add_symbol (scanner, 0, "include", INCLUDE_SYMBOL);
	g_scanner_scope_add_symbol (scanner, 0, "engine", ENGINE_SYMBOL);

	files = g_slist_prepend (files, g_strdup (filename));
	while (files != NULL)
	{
		filename = files->data;
		files = g_slist_delete_link (files, files);

		if (g_slist_find_custom (read_files, filename, (GCompareFunc) str_nequal))
		{
			g_warning ("Recursion in the gtkrc detected!");
			continue; /* skip this file since we've done it before... */
		}

		read_files = g_slist_prepend (read_files, filename);

		file = g_open (filename, O_RDONLY);
		if (file == -1)
		{
			g_warning ("Could not open file \"%s\"", filename);
		}
		else
		{
			g_scanner_input_file (scanner, file);
			while ((token = g_scanner_get_next_token (scanner)) != G_TOKEN_EOF)
			{
				GTokenType string_token;
				if (token == '@')
				{
					token = g_scanner_get_next_token (scanner);
					if (token != G_TOKEN_IDENTIFIER)
						continue;
					if (!g_slist_find_custom (*symbolic_colors, scanner->value.v_identifier, (GCompareFunc) str_nequal))
						*symbolic_colors = g_slist_append (*symbolic_colors, g_strdup (scanner->value.v_identifier));
					continue;
				}

				if (token != G_TOKEN_SYMBOL)
					continue;

				if (scanner->value.v_symbol == INCLUDE_SYMBOL)
				{
					string_token = g_scanner_get_next_token (scanner);
					if (string_token != G_TOKEN_STRING)
						continue;
					if (g_path_is_absolute (scanner->value.v_string))
					{
						files = g_slist_prepend (files, g_strdup (scanner->value.v_string));
					}
					else
					{
						gchar *basedir = g_path_get_dirname (filename);
						files = g_slist_prepend (files, g_build_path (G_DIR_SEPARATOR_S, basedir, scanner->value.v_string, NULL));
						g_free (basedir);
					}
				}
				else if (scanner->value.v_symbol == ENGINE_SYMBOL)
				{
					string_token = g_scanner_get_next_token (scanner);
					if (string_token != G_TOKEN_STRING)
						continue;
					if (!g_slist_find_custom (*engines, scanner->value.v_string, (GCompareFunc) str_nequal))
						*engines = g_slist_append (*engines, g_strdup (scanner->value.v_string));
				}

			}
		}
	}
}


gchar *
gtkrc_get_color_scheme (gchar *filename)
{
	gint file = -1;
	gchar *result = NULL;
	GSList *files = NULL;
	GSList *read_files = NULL;
	GTokenType token;
	GScanner *scanner = g_scanner_new (NULL);

	g_scanner_scope_add_symbol (scanner, 0, "include", INCLUDE_SYMBOL);
	g_scanner_scope_add_symbol (scanner, 0, "gtk_color_scheme", COLOR_SCHEME_SYMBOL);

	files = g_slist_prepend (files, g_strdup (filename));
	while (files != NULL)
	{
		filename = files->data;
		files = g_slist_delete_link (files, files);

		if (g_slist_find_custom (read_files, filename, (GCompareFunc) str_nequal))
		{
			g_warning ("Recursion in the gtkrc detected!");
			continue; /* skip this file since we've done it before... */
		}

		read_files = g_slist_prepend (read_files, filename);

		file = g_open (filename, O_RDONLY);
		if (file == -1)
		{
			g_warning ("Could not open file \"%s\"", filename);
		}
		else
		{
			g_scanner_input_file (scanner, file);
			while ((token = g_scanner_get_next_token (scanner)) != G_TOKEN_EOF)
			{
				GTokenType string_token;

				if (token != G_TOKEN_SYMBOL)
					continue;
				if (scanner->value.v_symbol == COLOR_SCHEME_SYMBOL)
				{
					if (g_scanner_get_next_token (scanner) != '=')
						continue;
					string_token = g_scanner_get_next_token (scanner);
					if (string_token != G_TOKEN_STRING)
						continue;
					if (result)
						g_free (result);
					result = g_strdup (scanner->value.v_string);
				}
			}
		}
	}
	return result;
}