/* *****************************************************************************
 * libg1m/format/lang.h -- the G1M language file format description.
 * 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/>.
 * ************************************************************************** */
#ifndef LIBG1M_FORMAT_LANG_H
# define LIBG1M_FORMAT_LANG_H
# include <libg1m.h>
# pragma pack(1)

/* ************************************************************************** */
/*  G1L - Language files for fx calculators                                   */
/* ************************************************************************** */
/*	It all starts with a header: */

struct g1l_subheader {
	/* identifier: is "PowerUSB" on original things */
	uint8_t identifier[8];

	/* OS information (raw binary format), e.g. 0x02,0x09 for 2.09. */
	uint8_t os_major;
	uint8_t os_minor;

	/* unknown bytes */
	uint8_t _unknown[2];

	/* message count */
	uint16_t message_count;
};

/*	Then comes a list of offsets, and the messages.
 *
 *	Each element of the offsets list is 16-bytes long.
 *	It is relative to the first element (which starts right after the
 *	offsets list - no alignment).
 *
 *	The messages are null-terminated - once you get the offsets, you get
 *	them completely. */
/* ************************************************************************** */
/*  G3L - Language files for Prizm                                            */
/* ************************************************************************** */
/*	Thanks to amazonka for his (minimalist) description of the G3L format
 *	at Cemetech. So the G3L format starts off with a header: */

struct g3l_subheader {
	/* a checksum */
	uint32_t checksum;

	/* magic:
	 *	- 0x04, 0x01, 0x00, 0x00 for language files;
	 *	- 0x02, 0x01, 0x00, 0x00 for function key files. */
	uint8_t magic[4];

	/* lol */
	uint8_t undocumented[14];

	/* size of the message zone size - unreliable (valid could have zero) */
	uint32_t message_zone_size;

	/* undocumented, again */
	uint8_t undocumented5[6];

	/* name of the language */
	uint8_t language_name2[28];

	/* size of the entire file */
	uint32_t filesize;

	/* size of the entire file - starts with an '@' */
	uint8_t internal_name[8];

	/* undocumented */
	uint8_t undocumented2[200];

	/* version number string: "XX.XX.XXXX" */
	uint8_t version[10];

	/* unused */
	uint8_t unused2[2];

	/* creation time: "YYYY.MMDD.HHMM" */
	uint8_t datetime[14];

	/* big undocumented thing */
	uint8_t undocumented3[3410];

	/* language name (zero terminated) */
	uint8_t language_name[16];

	/* language salutation (zero terminated) */
	uint8_t language_salutation[16];

	/* filename (extension included) */
	uint8_t g3l_filename[16];

	/* undocumented */
	uint8_t undocumented4[308];
};

/*	Then there is something amazonka names the "executable code section".
 *	This is in fact the message zone. */

struct g3l_lang_header {
	/* sequence: '4C 59 37 35 35 00 00 00 02' (LY755   ) */
	uint8_t sequence[9];

	/* unused byte. */
	uint8_t unused;

	/* number of messages ("possibly 0 base indexed") */
	uint32_t num;

	/* unused bytes */
	uint8_t unused2[2];
};

/*	Then we have offsets of all messages (4 bytes each),
 *	then messages themselves, zero-terminated.
 *
 *	The four last bytes of the files are a little footer, which is: */

struct g3l_footer {
	/* copy of the first checksum in the subheader */
	uint32_t checksum;
};

/*	This footer is not counted as part of the file. */

# pragma pack()
#endif /* LIBG1M_FORMAT_LANG_H */