/* *****************************************************************************
 * decode/mcs/var.c -- decode an MCS variable/alpha memory file.
 * Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
 *
 * This file is part of libg1m.
 * libg1m 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 3.0 of the License,
 * or (at your option) any later version.
 *
 * libg1m 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 libg1m; if not, see <http://www.gnu.org/licenses/>.
 * ************************************************************************** */
#include <libg1m/internals.h>

/**
 *	g1m_decode_mcs_var:
 *	Decode alpha memory (variables).
 *
 *	@arg	handle		the handle to make.
 *	@arg	buffer		the buffer to read from.
 *	@arg	head		the pre-filled head to complete and use.
 *	@return				the error code (0 if ok).
 */

int g1m_decode_mcs_var(g1m_mcsfile_t **handle, g1m_buffer_t *buffer,
	g1m_mcshead_t *head)
{
	uint_fast32_t length = head->g1m_mcshead_size;
	uint8_t *buf = alloca(length);
	int i;

	/* read the data */
	READ(buf, length)

	/* complete header */
	head->g1m_mcshead_count = length / (2 * sizeof(g1m_mcsbcd_t));
	int err = g1m_make_mcsfile(handle, head);
	if (err) return (err);
	g1m_mcsfile_t *h = *handle;

	/* copy */
	const g1m_mcsbcd_t *b = (void*)buf;
	for (i = 0; i < head->g1m_mcshead_count; i++) {
		g1m_bcd_frommcs(b++, &h->g1m_mcsfile_vars[i].g1m_mcscell_real);
		g1m_bcd_frommcs(b++, &h->g1m_mcsfile_vars[i].g1m_mcscell_imgn);
		h->g1m_mcsfile_vars[i].g1m_mcscell_flags = g1m_mcscellflag_used;
	}

	/* no problem, woop woop */
	return (0);
}