/* *****************************************************************************
 * decode/mcs/matrix.c -- decode an MCS matrix.
 * 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_matrix:
 *	Decode a matrix.
 *
 *	@arg	handle		the handle.
 *	@arg	buffer		the buffer to read from.
 *	@arg	length		the data length.
 *	@return				the error code (0 if ok).
 */

int g1m_decode_mcs_matrix(g1m_mcsfile_t *handle, g1m_buffer_t *buffer,
	uint_fast32_t length)
{
	g1m_mcs_cell_t **tab, *rws;
	int err = g1m_error_alloc;

	/* read header */
	DREAD(hd, mcs_matheader)

	/* correct endianess */
	hd.width = be16toh(hd.width);
	hd.height = be16toh(hd.height);

	/* log info */
	uint_fast32_t w = hd.width, h = hd.height;
	log_info("Matrix size is %" PRIuFAST32 "*%" PRIuFAST32, w, h);

	/* store dimensions */
	handle->head.width = w;
	handle->head.height = h;
	handle->cells = NULL;

	if (w && h) {
		/* alloc real matrix */
		tab = malloc(sizeof(g1m_mcs_cell_t*) * h);
		if (!tab) return (g1m_error_alloc);
		rws = malloc(sizeof(g1m_mcs_cell_t) * h * w);
		if (!rws) { free(tab); return (g1m_error_alloc); }

		/* copy */
		int one_imgn = 0;
		g1m_bcd_t bcd;
		for (uint_fast32_t y = 0; y < h; y++) {
			/* prepare index */
			tab[y] = &rws[y * w];

			/* read squares */
			for (uint_fast32_t x = 0; x < w; x++) {
				/* read the cell */
				GDREAD(rawbcd, bcd)
				one_imgn |= g1m_bcd_frommcs(&rawbcd, &bcd);

				/* store it */
				tab[y][x] = (g1m_mcs_cell_t){
					.real = bcd,
					.imgn = {},
					.used = 1
				};
			}
		}

		/* check imaginary parts */
		if (one_imgn) {
			for (uint_fast32_t y = 0; y < h; y++)
			  for (uint_fast32_t x = 0; x < w; x++) {
				GDREAD(rawbcd, bcd)
				if (g1m_bcd_has_special(&tab[y][x].real)) {
					g1m_bcd_frommcs(&rawbcd, &bcd);
					tab[y][x].imgn = bcd;
				}
			}
		}

		/* your sandwich, monsieur. */
		handle->cells = tab;
	}

	/* no error */
	return (0);

	/* in case of unexpected EOF */
fail:
	free(tab);
	free(rws);
	return (err);
}