/*
 * Copyright 2013 Canonical Ltd.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 3, 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 GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *     Ted Gould <ted.gould@canonical.com>
 */

#include "helpers.h"

/* Check to make sure we have the sections and keys we want */
static gboolean
verify_keyfile (GKeyFile * inkeyfile, const gchar * desktop)
{
	if (inkeyfile == NULL) return FALSE;

	if (!g_key_file_has_group(inkeyfile, "Desktop Entry")) {
		g_warning("Desktop file '%s' is missing the 'Desktop Entry' group", desktop);
		return FALSE;
	}

	if (!g_key_file_has_key(inkeyfile, "Desktop Entry", "Exec", NULL)) {
		g_warning("Desktop file '%s' is missing the 'Exec' key", desktop);
		return FALSE;
	}

	return TRUE;
}

/* Try to find a desktop file in a particular data directory */
static GKeyFile *
try_dir (const char * dir, const gchar * desktop)
{
	gchar * fullpath = g_build_filename(dir, "applications", desktop, NULL);
	GKeyFile * keyfile = g_key_file_new();

	/* NOTE: Leaving off the error here as we'll get a bunch of them,
	   so individuals aren't really useful */
	gboolean loaded = g_key_file_load_from_file(keyfile, fullpath, G_KEY_FILE_NONE, NULL);

	g_free(fullpath);

	if (!loaded) {
		g_key_file_free(keyfile);
		return NULL;
	}

	if (!verify_keyfile(keyfile, desktop)) {
		g_key_file_free(keyfile);
		return NULL;
	}

	return keyfile;
}

/* Find the keyfile that we need for a particular AppID and return it.
   Or NULL if we can't find it. */
GKeyFile *
keyfile_for_appid (const gchar * appid, gchar ** desktopfile)
{
	gchar * desktop = g_strdup_printf("%s.desktop", appid);

	const char * const * data_dirs = g_get_system_data_dirs();
	GKeyFile * keyfile = NULL;
	int i;

	keyfile = try_dir(g_get_user_data_dir(), desktop);
	if (keyfile != NULL && desktopfile != NULL && *desktopfile == NULL) {
		*desktopfile = g_build_filename(g_get_user_data_dir(), "applications", desktop, NULL);
	}

	for (i = 0; data_dirs[i] != NULL && keyfile == NULL; i++) {
		keyfile = try_dir(data_dirs[i], desktop);

		if (keyfile != NULL && desktopfile != NULL && *desktopfile == NULL) {
			*desktopfile = g_build_filename(data_dirs[i], "applications", desktop, NULL);
		}
	}

	g_free(desktop);

	return keyfile;
}