/**

  * $Id: cdi.c,v 1.7 2007-10-06 08:58:00 nkeynes Exp $

  *

  * 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 {

     char unknown[0x19];

     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;

 }

 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 = 2;

     else if( trail.cdi_version == CDI_V3_ID ) trail.cdi_version = 3;

     else return NULL; 

     fseek( f, trail.header_offset, SEEK_SET );

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

     disc = gdrom_image_new(f);

     if( disc == NULL ) {

 	fclose(f);

 	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" );

 	    disc->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" );

 		disc->close(disc);

 		return NULL;

 	    }

 	    fseek( f, 4, SEEK_CUR );

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

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

             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 );

 		    disc->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 );

 		    disc->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_XA1;

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

 		    break;

 		case 1:

 		    image->track[total_tracks].mode = GDROM_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 );

 		    disc->close(disc);

 		    return NULL;

 		}

 		break;

 	    default:

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

 		disc->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, 91, SEEK_CUR );

 	    } else {

 		fseek( f, 3, SEEK_CUR );

 	    }

 	}

     }

     image->track_count = total_tracks;

     image->filename = filename;

     return disc;

 }