/* *****************************************************************************
 * libg1m/internals.h -- the libg1m internals.
 * 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/>.
 *
 * This is the root of the libg1m internal headers. All source files shall
 * include this one to include all the headers (so they don't have to do
 * it themselves).
 * ************************************************************************** */
#ifndef LIBG1M_INTERNALS_H
# define LIBG1M_INTERNALS_H
# include <libg1m.h>
# include <libg1m/formatutils.h>
# include <libg1m/internals/log.h>
# include <string.h>
# include <libg1m/internals/endian.h>

/* ************************************************************************** */
/*  Macros and platform-specific functions                                    */
/* ************************************************************************** */
/* MS-Windows <3 (srsly) */
# if (defined(_WIN16) || defined(_WIN32) || defined(_WIN64)) \
	&& !defined(__WINDOWS__)
#  define __WINDOWS__
# endif

/* Macros */
# ifndef min
#  define min(A, B) ((A) < (B) ? (A) : (B))
# endif
# ifndef max
#  define max(A, B) ((A) > (B) ? (A) : (B))
# endif

/* Platform-specific functions */
# ifdef __WINDOWS__
#  define bzero(B, LEN) ((void)memset((B), 0, (LEN)))
# endif

/* ************************************************************************** */
/*  Macros and functions for parsing                                          */
/* ************************************************************************** */
/* read with EOF check */
#define READ(TO, SZ) { \
	int READ_err = (*buffer->read)(buffer->cookie, (void*)(TO), (SZ)); \
	if (READ_err) return (READ_err); \
}
#define GREAD(TO, SZ) \
	if ((err = (*buffer->read)(buffer->cookie, (void*)(TO), (SZ)))) \
		goto fail;
/* read with EOF check, declare var before */
#define DREAD(NAM, STRUCT) \
	struct STRUCT NAM; \
	READ(&NAM, sizeof(struct STRUCT))
#define GDREAD(NAM, STRUCT) \
	struct STRUCT NAM; \
	GREAD(&NAM, sizeof(struct STRUCT))
/* skip */
#define SKIP(SZ) { \
	int SKIP_err = g1m_skip(buffer, SZ, NULL); \
	if (SKIP_err) return (SKIP_err); \
}

/* ************************************************************************** */
/*  Specific parsing functions                                                */
/* ************************************************************************** */
typedef int (g1m_decode_function)(g1m_t*, g1m_buffer_t*,
	struct standard_header*);

/* types */
g1m_decode_function g1m_decode_g3p;
g1m_decode_function g1m_decode_c2p;
g1m_decode_function g1m_decode_mcs;
g1m_decode_function g1m_decode_eact;
g1m_decode_function g1m_decode_addin;
g1m_decode_function g1m_decode_addin_cg;
g1m_decode_function g1m_decode_lang;
g1m_decode_function g1m_decode_lang_cg;
g1m_decode_function g1m_decode_fkey;
g1m_decode_function g1m_decode_storage;

/* others */
int g1m_decode_fkey_cg_content(g1m_t *handle, g1m_buffer_t *buffer,
	uint_fast32_t zonesize, uint32_t *pchecksum);

/* ************************************************************************** */
/*  Picture utilities                                                         */
/* ************************************************************************** */
# define alloc_pixels(W, H) \
	malloc(sizeof(uint32_t*) * (H) + sizeof(uint32_t) * (W) * (H))
# define prepare_pixels(I, W, H) { \
	uint32_t *PIXPREP_line = (uint32_t*)&(I)[(H)]; \
	for (int PIXPREP_y = 0; PIXPREP_y < (H); PIXPREP_y++) { \
		(I)[PIXPREP_y] = PIXPREP_line; \
		PIXPREP_line += (W); \
	}}

/* just wanted to do this macro for fun. */
# define G1M_PROTOTYPE_PIX(NATURE) \
	void g1m_pixels_from_##NATURE(uint32_t **pixels, unsigned char *raw, \
		int width, int height); \
	void g1m_pixels_to_##NATURE(unsigned char *dest, uint32_t **pixels, \
		int width, int height);

G1M_PROTOTYPE_PIX(packed1bit)
G1M_PROTOTYPE_PIX(packed4bits)
G1M_PROTOTYPE_PIX(16bits)

/* ************************************************************************** */
/*  Utilities                                                                 */
/* ************************************************************************** */
/* Parsing */
int g1m_decode(g1m_t *handle, const char *path, g1m_buffer_t *buffer,
	g1m_type_t expected_type);

/* Making */
int g1m_make_mcs(g1m_t **h);

/* Free-ing */
void g1m_free_content(g1m_t *handle);
void g1m_free_mcsfile_content(g1m_mcsfile_t *handle);
void g1m_free_mcs(g1m_t *handle);
void g1m_free_line_content(g1m_line_t *line);

/* Skipping */
int g1m_skip(g1m_buffer_t *buffer, size_t size, uint_fast32_t *checksum);

/* Checksum-ing */
uint32_t g1m_checksum32(void *mem, size_t size, uint32_t checksum);

/* File buffer */
int g1m_filebuffer_read(void *vcookie, unsigned char *buf, size_t size);

#endif /* LIBG1M_INTERNALS_H */