/* *****************************************************************************
 * decode/std/lang.c -- decode a language 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>

/* ************************************************************************** */
/*  fx language files parsing                                                 */
/* ************************************************************************** */
/**
 *	g1m_decode_std_lang:
 *	Decode fx language files.
 *
 *	@arg	h			the libg1m handle to create.
 *	@arg	buffer		the buffer to read from.
 *	@return				the error code (0 if ok).
 */

int g1m_decode_std_lang(g1m_handle_t **h, g1m_buffer_t *buffer,
	struct standard_header *std)
{
	(void)std; int err;

	/* read the subheader */
	DREAD(hd, g1l_subheader)
	uint_fast16_t num = be16toh(hd.message_count) + 1;

	/* log */
	log_info("%" PRIuFAST16 " messages to read", num);

	/* beat the best, read the rest! */
	size_t data_size = std->filesize - sizeof(struct standard_header)
		- sizeof(struct g1l_subheader);
	uint8_t data[data_size];
	READ(data, data_size)

	/* make the handle */
	err = g1m_make_lang(h, g1m_platform_fx, num);
	if (err) return (err);
	g1m_handle_t *handle = *h;

	/* get the offset table */
	uint16_t *offsets = (uint16_t*)data;
	char *messages = (char*)(offsets + num);

	/* read messages */
	for (handle->g1m_handle_count = 0; handle->g1m_handle_count < (int)num;
	  handle->g1m_handle_count++) {
		int i = handle->g1m_handle_count;
		if (offsets[i] == (uint16_t)-1) {
			log_info("[#%d] -", i);
			continue;
		}

		/* correct offset and log */
		offsets[i] = be16toh(offsets[i]);
		log_info("[#%d] '%s' (0x%" PRIu16 ")", i,
			&messages[offsets[i]], offsets[i]);

		/* store */
		handle->g1m_handle_messages[i] = strdup(&messages[offsets[i]]);
		if (!handle->g1m_handle_messages[i]) goto fail;
		handle->g1m_handle_count++;
	}

	/* no error */
	return (0);

	/* omg fail! */
fail:
	g1m_free(*h); *h = NULL;
	return (err);
}

/* ************************************************************************** */
/*  Decoding language files for fx-CG/Prizm (G3L)                             */
/* ************************************************************************** */
/**
 *	g1m_decode_std_cg_lang:
 *	Decode fx-CG language file.
 *
 *	@arg	h			the handle to make.
 *	@arg	buffer		the buffer to read from.
 *	@arg	std			the standard header.
 *	@arg	sub			the standard subheader.
 *	@arg	prizm		the prizm-specific subheader.
 *	@arg	check		the checksum to feed.
 *	@return				the error code (0 if ok).
 */

int g1m_decode_std_cg_lang(g1m_handle_t **h, g1m_buffer_t *buffer,
	struct standard_header *std, struct standard_subheader *sub,
	struct _prizm_subheader *prizm, uint32_t *check)
{
	int err = g1m_error_alloc; uint8_t *data = NULL;
	(void)std; (void)prizm;

	/* read the subheader */
	DREAD(lhd, g3l_lang_header)
	*check = g1m_checksum32(&lhd, sizeof(struct g3l_lang_header), *check);

	/* read the data */
	size_t data_size = be32toh(sub->filesize) - sizeof(struct standard_header)
		- sizeof(struct standard_subheader) - sizeof(struct _prizm_subheader)
		- sizeof(struct g3l_lang_header) - 4;
	if (!(data = malloc(data_size))) goto fail;
	READ(data, data_size)
	*check = g1m_checksum32(data, data_size, *check);

	/* make the handle */
	int num = be32toh(lhd.num);
	err = g1m_make_lang(h, g1m_platform_cg, num);
	if (err) return (err);
	g1m_handle_t *handle = *h;

	/* setup the pointers */
	uint32_t *offsets = (void*)data;
	uint8_t *messages = (uint8_t*)&offsets[num + 1];

	/* read messages */
	for (handle->g1m_handle_count = 0; handle->g1m_handle_count < (int)num;
	  handle->g1m_handle_count++) {
		int i = handle->g1m_handle_count;
		if (offsets[i] == (uint32_t)-1) {
			log_info("[#%d] -", i);
			continue;
		}

		/* correct offset and log */
		offsets[i] = be32toh(offsets[i]);
		log_info("[#%d] '%s' (0x%" PRIu32 ")", i,
			&messages[offsets[i]], offsets[i]);

		/* store */
		handle->g1m_handle_messages[i] = strdup((char*)&messages[offsets[i]]);
		if (!handle->g1m_handle_messages[i]) goto fail;
	}

	/* done */
	free(data);
	return (0);

fail:
	free(data);
	g1m_free(*h); *h = NULL;
	return (err);
}