/**

 * $Id$

 *

 * CDI CD-image file support

 *

 * 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 <stdlib.h>

#include <stdio.h>

#include <stdint.h>

#include <fcntl.h>

#include <errno.h>

#include <sys/stat.h>

#include "gdrom/gdrom.h"

#define CDI_V2_ID 0x80000004

#define CDI_V3_ID 0x80000005

#define CDI_V35_ID 0x80000006

static gboolean cdi_image_is_valid( FILE *f );

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

struct gdrom_image_class cdi_image_class = { "DiscJuggler", "cdi", 

					     cdi_image_is_valid, cdi_image_open };

static const char TRACK_START_MARKER[20] = { 0,0,1,0,0,0,255,255,255,255,

                                       0,0,1,0,0,0,255,255,255,255 };

static const char EXT_MARKER[9] = {0,255,255,255,255,255,255,255,255 };

struct cdi_trailer {

    uint32_t cdi_version;

    uint32_t header_offset;

};

struct cdi_track_data {

    uint32_t pregap_length;

    uint32_t length;

    char unknown2[6];

    uint32_t mode;

    char unknown3[0x0c];

    uint32_t start_lba;

    uint32_t total_length;

    char unknown4[0x10];

    uint32_t sector_size;

    char unknown5[0x1D];

} __attribute__((packed));

gboolean cdi_image_is_valid( FILE *f )

{

    int len;

    struct cdi_trailer trail;

    fseek( f, -8, SEEK_END );

    len = ftell(f)+8;

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

    if( trail.header_offset >= len ||

        trail.header_offset == 0 )

	return FALSE;

    return trail.cdi_version == CDI_V2_ID || trail.cdi_version == CDI_V3_ID ||

	trail.cdi_version == CDI_V35_ID;

}

gdrom_disc_t cdi_image_open( const gchar *filename, FILE *f )

{

    gdrom_disc_t disc = NULL;

    gdrom_image_t image;

    int i,j;

    uint16_t session_count;

    uint16_t track_count;

    int total_tracks = 0;

    int posn = 0;

    long len;

    struct cdi_trailer trail;

    char marker[20];

    fseek( f, -8, SEEK_END );

    len = ftell(f)+8;

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

    if( trail.header_offset >= len ||

        trail.header_offset == 0 )

	return NULL;

    if( trail.cdi_version != CDI_V2_ID && trail.cdi_version != CDI_V3_ID &&

	trail.cdi_version != CDI_V35_ID ) {

	return NULL;

    }

    if( trail.cdi_version == CDI_V35_ID ) {

	fseek( f, -trail.header_offset, SEEK_END );

    } else {

	fseek( f, trail.header_offset, SEEK_SET );

    }

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

    disc = gdrom_image_new(filename, f);

    if( disc == NULL ) {

	ERROR("Unable to allocate memory!");

	return NULL;

    }

    image = (gdrom_image_t)disc;

    for( i=0; i< session_count; i++ ) {        

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

	if( track_count + total_tracks > 99 ) {

	    ERROR( "Invalid number of tracks, bad cdi image\n" );

	    gdrom_image_destroy_no_close(disc);

	    return NULL;

	}

        for( j=0; j<track_count; j++ ) {

            struct cdi_track_data trk;

            uint32_t new_fmt = 0;

	    uint8_t fnamelen = 0;

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

            if( new_fmt != 0 ) { /* Additional data 3.00.780+ ?? */

		fseek( f, 8, SEEK_CUR ); /* Skip */

            }

            fread( marker, 20, 1, f );

            if( memcmp( marker, TRACK_START_MARKER, 20) != 0 ) {

		ERROR( "Track start marker not found, error reading cdi image\n" );

		gdrom_image_destroy_no_close(disc);

		return NULL;

	    }

	    fseek( f, 4, SEEK_CUR );

            fread( &fnamelen, 1, 1, f );

            fseek( f, (int)fnamelen, SEEK_CUR ); /* skip over the filename */

	    fseek( f, 19, SEEK_CUR );

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

	    if( new_fmt == 0x80000000 ) {

		fseek( f, 10, SEEK_CUR );

	    } else {

		fseek( f, 2, SEEK_CUR );

	    }

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

	    image->track[total_tracks].session = i;

	    image->track[total_tracks].lba = trk.start_lba + 150;

	    image->track[total_tracks].sector_count = trk.length;

	    switch( trk.mode ) {

	    case 0:

		image->track[total_tracks].mode = GDROM_CDDA;

		image->track[total_tracks].sector_size = 2352;

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

		if( trk.sector_size != 2 ) {

		    ERROR( "Invalid combination of mode %d with size %d", trk.mode, trk.sector_size );

		    gdrom_image_destroy_no_close(disc);

		    return NULL;

		}

		break;

	    case 1:

		image->track[total_tracks].mode = GDROM_MODE1;

		image->track[total_tracks].sector_size = 2048;

		image->track[total_tracks].flags = 0x41;

		if( trk.sector_size != 0 ) {

		    ERROR( "Invalid combination of mode %d with size %d", trk.mode, trk.sector_size );

		    gdrom_image_destroy_no_close(disc);

		    return NULL;

		}

		break;

	    case 2:

		image->track[total_tracks].flags = 0x41;

		switch( trk.sector_size ) {

		case 0:

		    image->track[total_tracks].mode = GDROM_MODE2_FORM1;

		    image->track[total_tracks].sector_size = 2048;

		    break;

		case 1:

		    image->track[total_tracks].mode = GDROM_SEMIRAW_MODE2;

		    image->track[total_tracks].sector_size = 2336;

		    break;

		case 2:

		default:

		    ERROR( "Invalid combination of mode %d with size %d", trk.mode, trk.sector_size );

		    gdrom_image_destroy_no_close(disc);

		    return NULL;

		}

		break;

	    default:

		ERROR( "Unsupported track mode %d", trk.mode );

		gdrom_image_destroy_no_close(disc);

		return NULL;

	    }

	    image->track[total_tracks].offset = posn + 

		trk.pregap_length * image->track[total_tracks].sector_size ;

	    posn += trk.total_length * image->track[total_tracks].sector_size;

	    total_tracks++;

	    fread( marker, 1, 9, f );

	    if( memcmp( marker, EXT_MARKER, 9 ) == 0 ) {

		fseek( f, 79, SEEK_CUR );

	    } else {

		fseek( f, -9, SEEK_CUR );

	    }

	}

	fseek( f, 12, SEEK_CUR );

    }

    image->track_count = total_tracks;

    return disc;

}