/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2017 Richard Hughes <richard@hughsie.com>
 *
 * Licensed under the GNU Lesser General Public License Version 2.1
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include "config.h"

#include "fwupd-common-private.h"

#include <string.h>

/**
 * fwupd_checksum_guess_kind:
 * @checksum: A checksum
 *
 * Guesses the checksum kind based on the length of the hash.
 *
 * Returns: a #GChecksumType, e.g. %G_CHECKSUM_SHA1
 *
 * Since: 0.9.3
 **/
GChecksumType
fwupd_checksum_guess_kind (const gchar *checksum)
{
	guint len;
	if (checksum == NULL)
		return G_CHECKSUM_SHA1;
	len = strlen (checksum);
	if (len == 32)
		return G_CHECKSUM_MD5;
	if (len == 40)
		return G_CHECKSUM_SHA1;
	if (len == 64)
		return G_CHECKSUM_SHA256;
	if (len == 128)
		return G_CHECKSUM_SHA512;
	return G_CHECKSUM_SHA1;
}

static const gchar *
_g_checksum_type_to_string (GChecksumType checksum_type)
{
	if (checksum_type == G_CHECKSUM_MD5)
		return "MD5";
	if (checksum_type == G_CHECKSUM_SHA1)
		return "SHA1";
	if (checksum_type == G_CHECKSUM_SHA256)
		return "SHA256";
	if (checksum_type == G_CHECKSUM_SHA512)
		return "SHA512";
	return NULL;
}

/**
 * fwupd_checksum_format_for_display:
 * @checksum: A checksum
 *
 * Formats a checksum for display.
 *
 * Returns: text, or %NULL for invalid
 *
 * Since: 0.9.3
 **/
gchar *
fwupd_checksum_format_for_display (const gchar *checksum)
{
	GChecksumType kind = fwupd_checksum_guess_kind (checksum);
	return g_strdup_printf ("%s(%s)", _g_checksum_type_to_string (kind), checksum);
}

/**
 * fwupd_checksum_get_by_kind:
 * @checksums: (element-type utf8): checksums
 * @kind: a #GChecksumType, e.g. %G_CHECKSUM_SHA512
 *
 * Gets a specific checksum kind.
 *
 * Returns: a checksum from the array, or %NULL if not found
 *
 * Since: 0.9.4
 **/
const gchar *
fwupd_checksum_get_by_kind (GPtrArray *checksums, GChecksumType kind)
{
	for (guint i = 0; i < checksums->len; i++) {
		const gchar *checksum = g_ptr_array_index (checksums, i);
		if (fwupd_checksum_guess_kind (checksum) == kind)
			return checksum;
	}
	return NULL;
}

/**
 * fwupd_checksum_get_best:
 * @checksums: (element-type utf8): checksums
 *
 * Gets a the best possible checksum kind.
 *
 * Returns: a checksum from the array, or %NULL if nothing was suitable
 *
 * Since: 0.9.4
 **/
const gchar *
fwupd_checksum_get_best (GPtrArray *checksums)
{
	GChecksumType checksum_types[] = {
		G_CHECKSUM_SHA512,
		G_CHECKSUM_SHA256,
		G_CHECKSUM_SHA1,
		0 };
	for (guint i = 0; checksum_types[i] != 0; i++) {
		for (guint j = 0; j < checksums->len; j++) {
			const gchar *checksum = g_ptr_array_index (checksums, j);
			if (fwupd_checksum_guess_kind (checksum) == checksum_types[i])
				return checksum;
		}
	}
	return NULL;
}