/*
  $Id: common_interface.c,v 1.4 2005/01/06 03:09:11 rocky Exp $

  Copyright (C) 2004 Rocky Bernstein <rocky@panix.com>
  Copyright (C) 1998, 2002 Monty monty@xiph.org
  
  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.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
/******************************************************************
 *
 * CDROM communication common to all interface methods is done here 
 * (mostly ioctl stuff, but not ioctls specific to the 'cooked'
 * interface) 
 *
 ******************************************************************/

#include <math.h>
#include "common_interface.h"
#include <cdio/bytesex.h>
#include "utils.h"
#include "smallft.h"

int 
data_bigendianp(cdrom_drive_t *d)
{
  float lsb_votes=0;
  float msb_votes=0;
  int i,checked;
  int endiancache=d->bigendianp;
  float *a=calloc(1024,sizeof(float));
  float *b=calloc(1024,sizeof(float));
  long readsectors=5;
  int16_t *buff=malloc(readsectors*CDIO_CD_FRAMESIZE_RAW);

  /* look at the starts of the audio tracks */
  /* if real silence, tool in until some static is found */

  /* Force no swap for now */
  d->bigendianp=-1;
  
  cdmessage(d,"\nAttempting to determine drive endianness from data...");
  d->enable_cdda(d,1);
  for(i=0,checked=0;i<d->tracks;i++){
    float lsb_energy=0;
    float msb_energy=0;
    if(cdda_track_audiop(d,i+1)==1){
      long firstsector=cdda_track_firstsector(d,i+1);
      long lastsector=cdda_track_lastsector(d,i+1);
      int zeroflag=-1;
      long beginsec=0;
      
      /* find a block with nonzero data */
      
      while(firstsector+readsectors<=lastsector){
	int j;
	
	if(d->read_audio(d,buff,firstsector,readsectors)>0){
	  
	  /* Avoid scanning through jitter at the edges */
	  for(beginsec=0;beginsec<readsectors;beginsec++){
	    int offset=beginsec*CDIO_CD_FRAMESIZE_RAW/2;
	    /* Search *half* */
	    for(j=460;j<128+460;j++)
	      if(buff[offset+j]!=0){
		zeroflag=0;
		break;
	      }
	    if(!zeroflag)break;
	  }
	  if(!zeroflag)break;
	  firstsector+=readsectors;
	}else{
	  d->enable_cdda(d,0);
	  free(a);
	  free(b);
	  free(buff);
	  return(-1);
	}
      }

      beginsec*=CDIO_CD_FRAMESIZE_RAW/2;
      
      /* un-interleave for an fft */
      if(!zeroflag){
	int j;
	
	for(j=0;j<128;j++)
	  a[j]=UINT16_FROM_LE(buff[j*2+beginsec+460]);
	for(j=0;j<128;j++)
	  b[j]=UINT16_FROM_LE(buff[j*2+beginsec+461]);

	fft_forward(128,a,NULL,NULL);
	fft_forward(128,b,NULL,NULL);

	for(j=0;j<128;j++)
	  lsb_energy+=fabs(a[j])+fabs(b[j]);
	
	for(j=0;j<128;j++)
	  a[j]=UINT16_FROM_BE(buff[j*2+beginsec+460]);

	for(j=0;j<128;j++)
	  b[j]=UINT16_FROM_BE(buff[j*2+beginsec+461]);

	fft_forward(128,a,NULL,NULL);
	fft_forward(128,b,NULL,NULL);
	for(j=0;j<128;j++)msb_energy+=fabs(a[j])+fabs(b[j]);
      }
    }
    if(lsb_energy<msb_energy){
      lsb_votes+=msb_energy/lsb_energy;
      checked++;
    }else
      if(lsb_energy>msb_energy){
	msb_votes+=lsb_energy/msb_energy;
	checked++;
      }

    if(checked==5 && (lsb_votes==0 || msb_votes==0))break;
    cdmessage(d,".");
  }

  free(buff);
  free(a);
  free(b);
  d->bigendianp=endiancache;
  d->enable_cdda(d,0);

  /* How did we vote?  Be potentially noisy */
  if(lsb_votes>msb_votes){
    char buffer[256];
    cdmessage(d,"\n\tData appears to be coming back little endian.\n");
    sprintf(buffer,"\tcertainty: %d%%\n",(int)
	    (100.*lsb_votes/(lsb_votes+msb_votes)+.5));
    cdmessage(d,buffer);
    return(0);
  }else{
    if(msb_votes>lsb_votes){
      char buffer[256];
      cdmessage(d,"\n\tData appears to be coming back big endian.\n");
      sprintf(buffer,"\tcertainty: %d%%\n",(int)
	      (100.*msb_votes/(lsb_votes+msb_votes)+.5));
      cdmessage(d,buffer);
      return(1);
    }

    cdmessage(d,"\n\tCannot determine CDROM drive endianness.\n");
    return(bigendianp());
    return(-1);
  }
}

/************************************************************************/
/* Here we fix up a couple of things that will never happen.  yeah,
   right.  The multisession stuff is from Hannu's code; it assumes it
   knows the leadoud/leadin size. */

int 
FixupTOC(cdrom_drive_t *d, track_t i_tracks)
{
  int j;
  
  /* First off, make sure the 'starting sector' is >=0 */
  
  for( j=0; j<i_tracks; j++){
    if (d->disc_toc[j].dwStartSector<0 ) {
      cdmessage(d,"\n\tTOC entry claims a negative start offset: massaging"
		".\n");
      d->disc_toc[j].dwStartSector=0;
    }
    if( j<i_tracks-1 && d->disc_toc[j].dwStartSector>
       d->disc_toc[j+1].dwStartSector ) {
      cdmessage(d,"\n\tTOC entry claims an overly large start offset: massaging"
		".\n");
      d->disc_toc[j].dwStartSector=0;
    }

  }
  /* Make sure the listed 'starting sectors' are actually increasing.
     Flag things that are blatant/stupid/wrong */
  {
    lsn_t last=d->disc_toc[0].dwStartSector;
    for ( j=1; j<i_tracks; j++){
      if ( d->disc_toc[j].dwStartSector<last ) {
	cdmessage(d,"\n\tTOC entries claim non-increasing offsets: massaging"
		  ".\n");
	 d->disc_toc[j].dwStartSector=last;
	
      }
      last=d->disc_toc[j].dwStartSector;
    }
  }

#if LOOKED_OVER
  /* For a scsi device, the ioctl must go to the specialized SCSI
     CDROM device, not the generic device. */

  if (d->ioctl_fd != -1) {
    struct cdrom_multisession ms_str;
    int result;

    ms_str.addr_format = CDROM_LBA;
    result = ioctl(d->ioctl_fd, CDROMMULTISESSION, &ms_str);
    if (result == -1) return -1;

    if (ms_str.addr.lba > 100) {

      /* This is an odd little piece of code --Monty */

      /* believe the multisession offset :-) */
      /* adjust end of last audio track to be in the first session */
      for (j = i_tracks-1; j >= 0; j--) {
	if (j > 0 && !IS_AUDIO(d,j) && IS_AUDIO(d,j-1)) {
	  if ((d->disc_toc[j].dwStartSector > ms_str.addr.lba - 11400) &&
	      (ms_str.addr.lba - 11400 > d->disc_toc[j-1].dwStartSector))
	    d->disc_toc[j].dwStartSector = ms_str.addr.lba - 11400;
	  break;
	}
      }
      return 1;
    }
  }
#endif

  return 0;
}