/**

  * $Id: gdimage.c,v 1.6 2007-11-06 08:35:16 nkeynes Exp $

  *

  * GD-Rom image-file common functions. 

  *

  * 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 <netinet/in.h>

 #include "gdrom/gdrom.h"

 #include "gdrom/packet.h"

 #include "bootstrap.h"

 static void gdrom_image_destroy( gdrom_disc_t disc );

 static gdrom_error_t gdrom_image_read_sector( gdrom_disc_t disc, uint32_t lba, int mode, 

 					      unsigned char *buf, uint32_t *readlength );

 static gdrom_error_t gdrom_image_read_toc( gdrom_disc_t disc, unsigned char *buf );

 static gdrom_error_t gdrom_image_read_session( gdrom_disc_t disc, int session, unsigned char *buf );

 static gdrom_error_t gdrom_image_read_position( gdrom_disc_t disc, uint32_t lba, unsigned char *buf );

 static int gdrom_image_drive_status( gdrom_disc_t disc );

 /**

  * Initialize a gdrom_disc structure with the gdrom_image_* methods

  */

 void gdrom_image_init( gdrom_disc_t disc )

 {

     memset( disc, 0, sizeof(struct gdrom_disc) ); /* safety */

     disc->read_sector = gdrom_image_read_sector;

     disc->read_toc = gdrom_image_read_toc;

     disc->read_session = gdrom_image_read_session;

     disc->read_position = gdrom_image_read_position;

     disc->drive_status = gdrom_image_drive_status;

     disc->play_audio = NULL; /* not supported yet */

     disc->run_time_slice = NULL; /* not needed */

     disc->close = gdrom_image_destroy;

 }

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

 {

     gdrom_image_t image = (gdrom_image_t)calloc(sizeof(struct gdrom_image), 1);

     if( image == NULL ) {

 	return NULL;

     }

     image->disc_type = IDE_DISC_CDROM;

     image->file = f;

     gdrom_disc_t disc = (gdrom_disc_t)image;

     gdrom_image_init(disc);

     if( filename == NULL ) {

 	disc->name = NULL;

     } else {

 	disc->name = g_strdup(filename);

     }

     return disc;

 }

 static void gdrom_image_destroy( gdrom_disc_t disc )

 {

     int i;

     FILE *lastfile = NULL;

     gdrom_image_t img = (gdrom_image_t)disc;

     if( img->file != NULL ) {

 	fclose(img->file);

 	img->file = NULL;

     }

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

 	if( img->track[i].file != NULL && img->track[i].file != lastfile ) {

 	    lastfile = img->track[i].file;

 	    fclose(lastfile);

 	    img->track[i].file = NULL;

 	}

     }

     if( disc->name != NULL ) {

 	g_free( (gpointer)disc->name );

 	disc->name = NULL;

     }

     free( disc );

 }

 void gdrom_image_destroy_no_close( gdrom_disc_t disc )

 {

     int i;

     FILE *lastfile = NULL;

     gdrom_image_t img = (gdrom_image_t)disc;

     if( img->file != NULL ) {

 	img->file = NULL;

     }

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

 	if( img->track[i].file != NULL && img->track[i].file != lastfile ) {

 	    lastfile = img->track[i].file;

 	    fclose(lastfile);

 	    img->track[i].file = NULL;

 	}

     }

     if( disc->name != NULL ) {

 	g_free( (gpointer)disc->name );

 	disc->name = NULL;

     }

     free( disc );

 }

 static int gdrom_image_get_track_by_lba( gdrom_image_t image, uint32_t lba )

 {

     int i;

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

 	if( image->track[i].lba <= lba && 

 	    lba < (image->track[i].lba + image->track[i].sector_count) ) {

 	    return i+1;

 	}

     }

     return -1;

 }

 /**

  * Read a block from an image file, handling negative file offsets

  * with 0-fill.

  */

 static void gdrom_read_block( char *buf, int file_offset, int length, FILE *f )

 {

     if( file_offset < 0 ) {

 	int size = -file_offset;

 	if( size >= length ) {

 	    memset( buf, 0, length );

 	    return;

 	} else {

 	    memset( buf, 0, size );

 	    file_offset = 0;

 	    length -= size;

 	}

     }

     fseek( f, file_offset, SEEK_SET );

     fread( buf, length, 1, f );

 }

 static gdrom_error_t gdrom_image_read_sector( gdrom_disc_t disc, uint32_t lba,

 					      int mode, unsigned char *buf, uint32_t *length )

 {

     gdrom_image_t image = (gdrom_image_t)disc;

     int file_offset, read_len, track_no;

     FILE *f;

     track_no = gdrom_image_get_track_by_lba( image, lba );

     if( track_no == -1 ) {

 	return PKT_ERR_BADREAD;

     }

     struct gdrom_track *track = &image->track[track_no-1];

     file_offset = track->offset + track->sector_size * (lba - track->lba);

     read_len = track->sector_size;

     if( track->file != NULL ) {

 	f = track->file;

     } else {

 	f = image->file;

     }

     switch( mode ) {

     case 0x24:

     case 0x28:

 	switch( track->mode ) {

 	case GDROM_MODE1:

 	case GDROM_MODE2_XA1:

 	    gdrom_read_block( buf, file_offset, track->sector_size, f );

 	    break;

 	case GDROM_MODE2:

 	    read_len = 2048;

 	    file_offset += 8; /* skip the subheader */

 	    gdrom_read_block( buf, file_offset, 2048, f );

 	    break;

 	default:

 	    return PKT_ERR_BADREADMODE;

 	}

 	break;

     default:

 	return PKT_ERR_BADREADMODE;

     }

     *length = read_len;

     return PKT_ERR_OK;

 }

 static gdrom_error_t gdrom_image_read_toc( gdrom_disc_t disc, unsigned char *buf ) 

 {

     gdrom_image_t image = (gdrom_image_t)disc;

     struct gdrom_toc *toc = (struct gdrom_toc *)buf;

     int i;

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

 	toc->track[i] = htonl( image->track[i].lba ) | image->track[i].flags;

     }

     toc->first = 0x0100 | image->track[0].flags;

     toc->last = (image->track_count<<8) | image->track[i-1].flags;

     toc->leadout = htonl(image->track[i-1].lba + image->track[i-1].sector_count) |

 	image->track[i-1].flags;

     for( ;i<99; i++ )

 	toc->track[i] = 0xFFFFFFFF;

     return PKT_ERR_OK;

 }

 static gdrom_error_t gdrom_image_read_session( gdrom_disc_t disc, int session, unsigned char *buf )

 {

     gdrom_image_t image = (gdrom_image_t)disc;

     struct gdrom_track *last_track = &image->track[image->track_count-1];

     unsigned int end_of_disc = last_track->lba + last_track->sector_count;

     int i;

     buf[0] = 0x01; /* Disc status? */

     buf[1] = 0;

     if( session == 0 ) {

 	buf[2] = last_track->session+1; /* last session */

 	buf[3] = (end_of_disc >> 16) & 0xFF;

 	buf[4] = (end_of_disc >> 8) & 0xFF;

 	buf[5] = end_of_disc & 0xFF;

 	return PKT_ERR_OK;

     } else {

 	session--;

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

 	    if( image->track[i].session == session ) {

 		buf[2] = i+1; /* first track of session */

 		buf[3] = (image->track[i].lba >> 16) & 0xFF;

 		buf[4] = (image->track[i].lba >> 8) & 0xFF;

 		buf[5] = image->track[i].lba & 0xFF;

 		return PKT_ERR_OK;

 	    }

 	}

 	return PKT_ERR_BADFIELD; /* No such session */

     }

 }

 static gdrom_error_t gdrom_image_read_position( gdrom_disc_t disc, uint32_t lba, unsigned char *buf )

 {

     gdrom_image_t image = (gdrom_image_t)disc;

     int track_no = gdrom_image_get_track_by_lba( image, lba );

     if( track_no == -1 ) {

 	track_no = 1;

 	lba = 150;

     }

     struct gdrom_track *track = &image->track[track_no-1];

     uint32_t offset = lba - track->lba;

     buf[4] = track->flags;

     buf[5] = track_no;

     buf[6] = 0x01; /* ?? */

     buf[7] = (offset >> 16) & 0xFF;

     buf[8] = (offset >> 8) & 0xFF;

     buf[9] = offset & 0xFF;

     buf[10] = 0;

     buf[11] = (lba >> 16) & 0xFF;

     buf[12] = (lba >> 8) & 0xFF;

     buf[13] = lba & 0xFF;

     return PKT_ERR_OK;

 }

 static int gdrom_image_drive_status( gdrom_disc_t disc ) 

 {

     gdrom_image_t image = (gdrom_image_t)disc;

     return image->disc_type | IDE_DISC_READY;

 }

 void gdrom_image_dump_info( gdrom_disc_t d ) {

     gdrom_image_t disc = (gdrom_image_t)d;

     int i;

     int last_session = disc->track[disc->track_count-1].session;

     gboolean is_bootable = FALSE;

     INFO( "Disc ID: %s, %d tracks in %d sessions", disc->mcn, disc->track_count, 

 	  disc->track[disc->track_count-1].session + 1 );

     if( last_session > 0 ) {

 	/* Boot track is the first data track of the last session, provided that it 

 	 * cannot be a single-session disc.

 	 */

 	int boot_track = -1;

 	for( i=disc->track_count-1; i>=0 && disc->track[i].session == last_session; i-- ) {

 	    if( disc->track[i].flags & TRACK_DATA ) {

 		boot_track = i;

 	    }

 	}

 	if( boot_track != -1 ) {

 	    unsigned char boot_sector[MAX_SECTOR_SIZE];

 	    uint32_t length = sizeof(boot_sector);

 	    if( d->read_sector( d, disc->track[boot_track].lba, 0x28,

 				   boot_sector, &length ) == PKT_ERR_OK ) {

 		bootstrap_dump(boot_sector, FALSE);

 		is_bootable = TRUE;

 	    }

 	}

     }

     if( !is_bootable ) {

 	WARN( "Disc does not appear to be bootable" );

     }

 }