/* ****************************************************************************
 * fontchar/open.c -- parse the binary set file produced from the
 *                    community-made FONTCHARACTER reference.
 * Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
 *
 * This file is part of libcasio.
 * libcasio 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.
 *
 * libcasio 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 libcasio; if not, see <http://www.gnu.org/licenses/>.
 * ************************************************************************* */
#include "fontchar.h"
#include "reference.h"

/* Globals. */

casio_uint8_t* CASIO_EXPORT casio_fontchar_leaders = NULL;

/**
 *	casio_open_fontchar_ref:
 *	Open the FONTCHARACTER reference.
 */

int CASIO_EXPORT casio_open_fontchar_ref(void)
{
	int err, num, i;
	casio_stream_t *stream;
	struct file_magic magic;
	struct file_header header;
	size_t char_size;
	const char *chars = NULL;
	const char *pool = NULL;

	/* Open the file. */
	err = casio_open_nat(casio_local_fs, &stream, PATH,
		0, CASIO_OPENMODE_READ);
	if (err) return (err);

	/* Read the magic. */
	err = casio_read(stream, &magic, sizeof(magic));
	if (err) goto fail;
	if (memcmp(magic.magic, FONTCHAR_MAGIC, 8)) {
		msg((ll_error, "Invalid FONTCHARACTER file magic."));

		err = casio_error_magic;
		goto fail;
	}
	if (magic.version != 0x01) {
		msg((ll_error, "Unsupported FONTCHARACTER file version."))

		err = casio_error_magic;
		goto fail;
	}

	/* Read the rest of the header. */
	err = casio_read(stream, &header, sizeof(header));
	if (err) goto fail;
	if (~header.flags & FONTCHAR_FLAG_UNI) {
		msg((ll_error, "Unicode support is required by the library!"));

		err = casio_error_magic;
		goto fail;
	}

	header.total = be16toh(header.total);
	header.format = be16toh(header.format);
	header.checksum = be32toh(header.checksum);
	header.filesize = be32toh(header.filesize);
	header.datasize = be32toh(header.datasize);

	char_size = 16;
	if (header.flags & FONTCHAR_FLAG_CAT)
		char_size += 4;
	if (header.flags & FONTCHAR_FLAG_NEWCAT)
		char_size += 4;
	if (header.flags & FONTCHAR_FLAG_CTF)
		char_size += 4;
	if (header.flags & FONTCHAR_FLAG_CASEMUL)
		char_size += 4;

	/* Check that the filesize corresponds. */
	if (header.filesize != sizeof(struct file_lead)
		+ sizeof(struct file_header)
		+ sizeof(struct file_lead) * header.leading
		+ char_size * header.total) {
		msg((ll_error, "Erroneous file size field!"));

		err = casio_error_magic;
		goto fail;
	}

	/* Get the leading characters. */
	num = header.leading;
	casio_fontchar_leaders = casio_alloc(num, 1);
	for (i = 0; i < num; i++) {
		struct file_lead lead;

		err = casio_read(stream, &lead, sizeof(lead));
		if (err) goto fail;

		casio_fontchar_leaders[i] = lead.code;
	}

	/* Prepare gathering of the characters and data pool. */
	chars = casio_alloc(char_size, num);
	if (!chars) {
		err = casio_error_alloc;
		goto fail;
	}

	err = casio_read(stream, &chars, char_size * num);
	if (err)
		goto fail;

	pool = casio_alloc(

	/* Get the characters. */
	num = header.total;
	chars = casio_alloc(char_size, num);
	if (!chars) {
		err = casio_error_alloc;
		goto fail;
	}
	for (i = 0; i < num; i++) {
		struct file_char ch;

		/* Careful: char_size can not be `sizeof(char_size)`!
		 * (but `ch` is always big enough to read the character data
		 *  into it) */
		err = casio_read(stream, &ch, char_size);
		if (err) goto fail;


	}

	/* TODO */
	return (0);
fail:
	casio_free(stream);
	return (casio_error_op);
}