/**

  * $Id: gdrom.c,v 1.9 2006-06-26 10:30:42 nkeynes Exp $

  *

  * GD-Rom  access 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 <stdio.h>

 #include <errno.h>

 #include "gdrom/ide.h"

 #include "gdrom/gdrom.h"

 #include "gdrom/packet.h"

 #include "dream.h"

 static void gdrom_image_destroy( gdrom_disc_t );

 static gdrom_error_t gdrom_image_read_sectors( gdrom_disc_t, uint32_t, uint32_t, int, char *, uint32_t * );

 gdrom_image_class_t gdrom_image_classes[] = { &nrg_image_class, &cdi_image_class, NULL };

 gdrom_disc_t gdrom_disc = NULL;

 char *gdrom_mode_names[] = { "Mode1", "Mode2", "XA 1", "XA2", "Audio", "GD-Rom" };

 uint32_t gdrom_sector_size[] = { 2048, 2336, 2048, 2324, 2352, 2336 };

 gdrom_disc_t gdrom_image_open( const gchar *filename )

 {

     const gchar *ext = strrchr(filename, '.');

     gdrom_disc_t disc = NULL;

     FILE *f = fopen(filename, "ro");

     int i,j;

     gdrom_image_class_t extclz = NULL;

     if( f == NULL ) {

 	ERROR("Unable to open file '%s': %s", filename, strerror(errno));

 	return NULL;

     }

     /* try extensions */

     if( ext != NULL ) {

 	ext++; /* Skip the '.' */

 	for( i=0; gdrom_image_classes[i] != NULL; i++ ) {

 	    if( strcasecmp( gdrom_image_classes[i]->extension, ext ) == 0 ) {

 		extclz = gdrom_image_classes[i];

 		if( extclz->is_valid_file(f) ) {

 		    disc = extclz->open_image_file(filename, f);

 		    if( disc != NULL )

 			return disc;

 		}

 		break;

 	    }

 	}

     }

     /* Okay, fall back to magic */

     for( i=0; gdrom_image_classes[i] != NULL; i++ ) {

 	if( gdrom_image_classes[i] != extclz &&

 	    gdrom_image_classes[i]->is_valid_file(f) ) {

 	    disc = gdrom_image_classes[i]->open_image_file(filename, f);

 	    if( disc != NULL )

 		return disc;

 	}

     }

     fclose(f);

     return NULL;

 }

 gdrom_disc_t gdrom_image_new( FILE *file )

 {

     struct gdrom_disc *disc = (struct gdrom_disc *)calloc(1, sizeof(struct gdrom_disc));

     if( disc == NULL )

 	return NULL;

     disc->read_sectors = gdrom_image_read_sectors;

     disc->close = gdrom_image_destroy;

     disc->disc_type = IDE_DISC_CDROM;

     disc->file = file;

     return disc;

 }

 static void gdrom_image_destroy( gdrom_disc_t disc )

 {

     if( disc->file != NULL ) {

 	fclose(disc->file);

 	disc->file = NULL;

     }

     free( disc );

 }

 static gdrom_error_t gdrom_image_read_sectors( gdrom_disc_t disc, uint32_t sector,

 					       uint32_t sector_count, int mode, char *buf,

 					       uint32_t *length )

 {

     int i, file_offset, read_len;

     struct gdrom_track *track = NULL;

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

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

 	    (sector + sector_count) <= (disc->track[i].lba + disc->track[i].sector_count) ) {

 	    track = &disc->track[i];

 	    break;

 	}

     }

     if( track == NULL )

 	return PKT_ERR_BADREAD;

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

     read_len = track->sector_size * sector_count;

     switch( mode ) {

     case GDROM_GD:

 	// Temporarily comment this out - it's wrong, but...

 	//	if( track->mode != GDROM_GD ) 

 	//    return PKT_ERR_BADREADMODE;

 	// break;

     case GDROM_MODE1:

 	switch( track->mode ) {

 	case GDROM_MODE1:

 	case GDROM_MODE2_XA1:

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

 	    fread( buf, track->sector_size, sector_count, disc->file );

 	    break;

 	case GDROM_MODE2:

 	    read_len = sector_count * 2048;

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

 	    while( sector_count > 0 ) {

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

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

 		file_offset += track->sector_size;

 		buf += 2048;

 		sector_count--;

 	    }

 	    break;

 	default:

 	    return PKT_ERR_BADREADMODE;

 	}

 	break;

     default:

 	return PKT_ERR_BADREADMODE;

     }

     *length = read_len;

     return PKT_ERR_OK;

 }

 uint32_t gdrom_read_sectors( uint32_t sector, uint32_t sector_count,

 			     int mode, char *buf, uint32_t *length )

 {

     if( gdrom_disc == NULL )

 	return PKT_ERR_NODISC; /* No media */

     return gdrom_disc->read_sectors( gdrom_disc, sector, sector_count, mode, buf, length );

 }

 void gdrom_dump_disc_info( gdrom_disc_t disc ) {

     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[2048];

 	    uint32_t length = sizeof(boot_sector);

 	    if( disc->read_sectors( disc, disc->track[boot_track].lba, 1, GDROM_MODE1,

 				    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" );

 }

 gdrom_error_t gdrom_get_toc( char *buf ) 

 {

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

     int i;

     if( gdrom_disc == NULL )

 	return PKT_ERR_NODISC;

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

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

     }

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

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

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

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

     for( ;i<99; i++ )

 	toc->track[i] = 0xFFFFFFFF;

     return PKT_ERR_OK;

 }

 gdrom_error_t gdrom_get_info( char *buf, int session )

 {

     if( gdrom_disc == NULL )

 	return PKT_ERR_NODISC;

     struct gdrom_track *last_track = &gdrom_disc->track[gdrom_disc->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<gdrom_disc->track_count; i++ ) {

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

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

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

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

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

 		return PKT_ERR_OK;

 	    }

 	}

 	return PKT_ERR_BADFIELD; /* No such session */

     }

 }

 void gdrom_mount_disc( gdrom_disc_t disc ) 

 {

     gdrom_unmount_disc();

     gdrom_disc = disc;

     idereg.disc = disc->disc_type | IDE_DISC_READY;

     gdrom_dump_disc_info( disc );

 }

 gdrom_disc_t gdrom_mount_image( const gchar *filename )

 {

     gdrom_disc_t disc = gdrom_image_open(filename);

     if( disc != NULL )

 	gdrom_mount_disc( disc );

     return disc;

 }

 void gdrom_unmount_disc( ) 

 {

     if( gdrom_disc != NULL ) {

 	gdrom_disc->close(gdrom_disc);

     }

     gdrom_disc = NULL;

     idereg.disc = IDE_DISC_NONE;

 }

 gboolean gdrom_is_mounted( void ) 

 {

     return gdrom_disc != NULL;

 }