/**

 * $Id: nrg.c,v 1.7 2007-10-28 07:23:46 nkeynes Exp $

 *

 * Nero (NRG) CD file format. File information stolen shamelessly from

 * libcdio.

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 */

#include <assert.h>

#include <stdio.h>

#include <errno.h>

#include <netinet/in.h>

#include "gdrom/gdrom.h"

#include "dream.h"

static gboolean nrg_image_is_valid( FILE *f );

static gdrom_disc_t nrg_image_open( const gchar *filename, FILE *f );

struct gdrom_image_class nrg_image_class = { "Nero", "nrg", 

					     nrg_image_is_valid, nrg_image_open };

#define NERO_V55_ID  0x4e455235 

#define NERO_V50_ID  0x4e45524f 

/* Courtesy of libcdio */

/* 5.0 or earlier */

#define NERO_ID  0x4e45524f  /* Nero pre 5.5.x */

#define CUES_ID  0x43554553  /* Nero pre version 5.5.x-6.x */

#define DAOI_ID  0x44414f49

#define ETNF_ID  0x45544e46

#define SINF_ID  0x53494e46  /* Session information */

#define END_ID  0x454e4421

/* 5.5+ only */

#define NER5_ID  0x4e455235  /* Nero version 5.5.x */

#define CDTX_ID  0x43445458  /* CD TEXT */

#define CUEX_ID  0x43554558  /* Nero version 5.5.x-6.x */

#define DAOX_ID  0x44414f58  /* Nero version 5.5.x-6.x */

#define ETN2_ID  0x45544e32

#define MTYP_ID  0x4d545950  /* Disc Media type? */

union nrg_footer {

    struct nrg_footer_v50 {

	uint32_t dummy;

	uint32_t id;

	uint32_t offset;

    } v50;

    struct nrg_footer_v55 {

	uint32_t id;

	uint64_t offset;

    } v55;

};

struct nrg_chunk {

    uint32_t id;

    uint32_t length;

};

struct nrg_etnf {

    uint32_t offset;

    uint32_t length;

    uint32_t mode;

    uint32_t lba;

    uint32_t padding;

};

struct nrg_cues {

    uint8_t type;

    uint8_t track;

    uint8_t control;

    uint8_t pad;

    uint32_t addr;

};

struct nrg_daoi {

    uint32_t length;

    char mcn[14];

    uint8_t disc_mode;

    uint8_t unknown[2]; /* always 01 01? */

    uint8_t track_count;

    struct nrg_daoi_track {

	char unknown[10];

	uint32_t sector_size __attribute__((packed)); /* Always 0? */

	uint8_t mode;

	uint8_t unknown2[3]; /* Always 00 00 01? */

	uint32_t pregap __attribute__((packed));

	uint32_t offset __attribute__((packed));

	uint32_t end __attribute__((packed));

    } track[0];

} __attribute__((packed));

/**

 * Convert an 8-bit BCD number to normal integer form. 

 * Eg, 0x79 => 79

 */

uint8_t static bcd_to_uint8( uint8_t bcd )

{

    return (bcd & 0x0F) + (((bcd & 0xF0)>>4)*10);

}

/**

 * Convert a 32 bit MSF address (BCD coded) to the

 * equivalent LBA form. 

 * Eg, 0x

 */

uint32_t static msf_to_lba( uint32_t msf )

{

    msf = ntohl(msf);

    int f = bcd_to_uint8(msf);

    int s = bcd_to_uint8(msf>>8);

    int m = bcd_to_uint8(msf>>16);

    return (m * 60 + s) * 75 + f;

}

uint32_t static nrg_track_mode( uint8_t mode )

{

    switch( mode ) {

    case 0: return GDROM_MODE1;

    case 2: return GDROM_MODE2_XA1;

    case 3: return GDROM_MODE2;

    case 7: return GDROM_CDDA;

    default: 

	ERROR( "Unrecognized track mode %d in Nero image", mode );

	return -1;

    }

}

static gboolean nrg_image_is_valid( FILE *f )

{

    union nrg_footer footer;

    fseek( f, -12, SEEK_END );

    fread( &footer, sizeof(footer), 1, f );

    if( ntohl(footer.v50.id) == NERO_V50_ID ) {

	return TRUE;

    } else {

	return FALSE;

    }

}

static gdrom_disc_t nrg_image_open( const gchar *filename, FILE *f )

{

    union nrg_footer footer;

    struct nrg_chunk chunk;

    struct nrg_daoi *dao;

    gdrom_disc_t disc;

    gdrom_image_t image;

    gboolean end = FALSE;

    int session_id = 0;

    int session_track_id = 0;

    int track_id = 0;

    int cue_track_id = 0, cue_track_count = 0;

    int i;

    fseek( f, -12, SEEK_END );

    fread( &footer, sizeof(footer), 1, f );

    if( ntohl(footer.v50.id) == NERO_V50_ID ) {

	INFO( "Loading Nero 5.0 image" );

	fseek( f, ntohl(footer.v50.offset), SEEK_SET );

    } else if( ntohl(footer.v55.id) == NERO_V55_ID ) {

	INFO( "Loading Nero 5.5+ image" );

	fseek( f, ntohl(footer.v55.offset), SEEK_SET );

    } else {

	/* Not a (recognized) Nero image */

	return NULL;

    }

    disc = gdrom_image_new(filename, f);

    if( disc == NULL ) {

	ERROR("Unable to allocate memory!");

	return NULL;

    }

    image = (gdrom_image_t)disc;

    do {

	fread( &chunk, sizeof(chunk), 1, f );

	chunk.length = ntohl(chunk.length);

	char data[chunk.length];

	fread( data, chunk.length, 1, f );

	switch( ntohl(chunk.id) ) {

	case CUES_ID:

	    cue_track_id = track_id;

	    cue_track_count = ((chunk.length / sizeof(struct nrg_cues)) >> 1) - 1;

	    track_id += cue_track_count;

	    for( i=0; i<chunk.length; i+= sizeof(struct nrg_cues) ) {

		struct nrg_cues *cue = (struct nrg_cues *)(data+i);

		int track = 0;

		if( cue->track == 0 )

		    continue; /* Track 0. Leadin? always 0? */

		if( cue->track == 0xAA ) { /* end of disc */

		    image->track[track_id-1].sector_count =

			msf_to_lba( cue->addr ) - image->track[track_id-1].lba;

		} else {

		    track = cue_track_id + bcd_to_uint8(cue->track) - 1;

		    if( (cue->control & 0x01) == 0 ) { 

			/* Pre-gap address. */

			if( track != 0 ) {

			    image->track[track-1].sector_count = 

				msf_to_lba( cue->addr ) - image->track[track-1].lba;

			}

		    } else { /* Track-start address */

			image->track[track].lba = msf_to_lba( cue->addr );

			image->track[track].flags = cue->type;

		    }

		}

	    }

	    break;

	case DAOI_ID:

	    dao = (struct nrg_daoi *)data;

	    memcpy( image->mcn, dao->mcn, 13 );

	    image->mcn[13] = '\0';

	    assert( dao->track_count * 30 + 22 == chunk.length );

	    assert( dao->track_count == cue_track_count );

	    for( i=0; i<dao->track_count; i++ ) {

		image->track[cue_track_id].sector_size = ntohl(dao->track[i].sector_size);

		image->track[cue_track_id].offset = ntohl(dao->track[i].offset);

		image->track[cue_track_id].mode = nrg_track_mode( dao->track[i].mode );

		image->track[cue_track_id].sector_count =

		    (ntohl(dao->track[i].end) - ntohl(dao->track[i].offset))/

		    ntohl(dao->track[i].sector_size);

		cue_track_id++;

	    }

	    break;

	case SINF_ID: 

	    /* Data is a single 32-bit number representing number of tracks in session */

	    i = ntohl( *(uint32_t *)data );

	    while( i-- > 0 )

		image->track[session_track_id++].session = session_id;

	    session_id++;

	    break;

	case ETNF_ID:

	    for( i=0; i < chunk.length; i+= 0x14 ) {

		struct nrg_etnf *etnf = (struct nrg_etnf *)(data+i);

		image->track[track_id].offset = ntohl(etnf->offset);

		image->track[track_id].lba = ntohl(etnf->lba) + (i+1)*GDROM_PREGAP;

		image->track[track_id].mode = nrg_track_mode( ntohl(etnf->mode) );

		if( image->track[track_id].mode == -1 ) {

		    gdrom_image_destroy_no_close(disc);

		    return NULL;

		}

		if( image->track[track_id].mode == GDROM_CDDA )

		    image->track[track_id].flags = 0x01;

		else

		    image->track[track_id].flags = 0x01 | TRACK_DATA;

		image->track[track_id].sector_size = GDROM_SECTOR_SIZE(image->track[track_id].mode);

		image->track[track_id].sector_count = ntohl(etnf->length) / 

		    image->track[track_id].sector_size;

		track_id++;

	    }

	    break;

	case END_ID:

	    end = TRUE;

	    break;

	}

    } while( !end );

    image->track_count = track_id;

    return disc;

}