/* -*-C-*-

$Id$

Copyright (c) 2002 Massachusetts Institute of Technology

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.
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "filter-frame.h"

struct f_context
{
  unsigned int m;
  unsigned int delay;
  REAL mu;
  REAL * h;
};

static void usage (void);
static unsigned int convert_index_arg (char * s, unsigned int limit);
static REAL convert_real_arg (char * s);
static void cancel_noise (REAL * ib, REAL * ob, unsigned int ndata, void * cv);
static void cancel_tones (REAL * ib, REAL * ob, unsigned int ndata, void * cv);

void
main (int argc, char ** argv)
{
  struct f_context c;
  filter f;

  if (argc != 5)
    usage ();
  (c.m) = (convert_index_arg ((argv[1]), 8196));
  (c.delay) = (convert_index_arg ((argv[3]), 8196));
  (c.mu) = (convert_real_arg (argv[2]));
  (c.h) = (xmalloc ((c.m) * (sizeof (REAL))));
  {
    REAL * sh = (c.h);
    REAL * eh = (sh + (c.m));
    while (sh < eh)
      (*sh++) = 0.;
  }
  switch (convert_index_arg ((argv[4]), 2))
    {
    case 0:
      f = cancel_noise;
      break;
    case 1:
      f = cancel_tones;
      break;
    }
  apply_filter ((make_filter_state ((fileno (stdin)),
				    (fileno (stdout)),
				    8000,
				    ((c.m) + (c.delay)))),
		f,
		(&c));
  exit (0);
}

static void
usage (void)
{
  fprintf (stderr, "usage: PROGRAM ORDER MU DELAY TYPE\n");
  exit (1);
}

static unsigned int
convert_index_arg (char * s, unsigned int limit)
{
  char * ep;
  long i = (strtol (s, (&ep), 0));
  if ((*ep) != 0)
    {
      fprintf (stderr, "Ill-formed integer argument: %s\n", s);
      exit (1);
    }
  if ((i < 0) || (i >= limit))
    {
      fprintf (stderr, "Integer argument out of range: %d\n", i);
      exit (1);
    }
  return (i);
}

static REAL
convert_real_arg (char * s)
{
  char * ep;
  REAL i = (strtod (s, (&ep)));
  if ((*ep) != 0)
    {
      fprintf (stderr, "Ill-formed real argument: %s\n", s);
      exit (1);
    }
  return (i);
}

static void
cancel_noise (REAL * ib, REAL * ob, unsigned int ndata, void * cv)
{
  REAL * si = ib;
  REAL * ei = (si + ndata);
  REAL * so = ob;
  struct f_context * c = cv;
  unsigned int m = (c->m);
  unsigned int delay = (c->delay);
  REAL mu = (c->mu);
  REAL * h = (c->h);
  REAL * u;
  REAL * up;
  REAL * hp;
  REAL temp;

  while (si < ei)
    {
      u = (si - delay);
      up = (u - m);
      hp = (h + m);
      temp = ((*up++) * (*--hp));
      while (up < u)
	temp += ((*up++) * (*--hp));
      (*so++) = temp;
      temp = ((*si++) - temp);
      temp *= mu;
      up = (u - m);
      hp = (h + m);
      while (up < u)
	(*--hp) += ((*up++) * temp);
    }
}

static void
cancel_tones (REAL * ib, REAL * ob, unsigned int ndata, void * cv)
{
  REAL * si = ib;
  REAL * ei = (si + ndata);
  REAL * so = ob;
  struct f_context * c = cv;
  unsigned int m = (c->m);
  unsigned int delay = (c->delay);
  REAL mu = (c->mu);
  REAL * h = (c->h);
  REAL * u;
  REAL * up;
  REAL * hp;
  REAL temp;

  while (si < ei)
    {
      u = (si - delay);
      up = (u - m);
      hp = (h + m);
      temp = ((*up++) * (*--hp));
      while (up < u)
	temp += ((*up++) * (*--hp));
      temp = ((*si++) - temp);
      (*so++) = temp;
      temp *= mu;
      up = (u - m);
      hp = (h + m);
      while (up < u)
	(*--hp) += ((*up++) * temp);
    }
}