/**

 * $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;

}