/**

 * $Id: gdimage.c,v 1.1 2007-01-31 10:58:42 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 "gdrom/gdrom.h"

#include "gdrom/packet.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, 

					      char *buf, uint32_t *readlength );

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

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

static gdrom_error_t gdrom_image_read_position( gdrom_disc_t disc, uint32_t lba, 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( 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);

    return disc;

}

static void gdrom_image_destroy( gdrom_disc_t disc )

{

    gdrom_image_t img = (gdrom_image_t)disc;

    if( img->file != NULL ) {

	fclose(img->file);

	img->file = 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;

}

static gdrom_error_t gdrom_image_read_sector( gdrom_disc_t disc, uint32_t lba,

					      int mode, char *buf, uint32_t *length )

{

    gdrom_image_t image = (gdrom_image_t)disc;

    int i, file_offset, read_len, track_no;

    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;

    switch( mode ) {

    case 0x24:

    case 0x28:

	switch( track->mode ) {

	case GDROM_MODE1:

	case GDROM_MODE2_XA1:

	    fseek( image->file, file_offset, SEEK_SET );

	    fread( buf, track->sector_size, 1, image->file );

	    break;

	case GDROM_MODE2:

	    read_len = 2048;

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

	    fseek( image->file, file_offset, SEEK_SET );

	    fread( buf, 2048, 1, image->file );

	    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, 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, 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, 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;

}

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 ) {

	    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" );

    }

}