//dtmf.c:

/*
 *      Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2012
 *
 *  This file is part of libroardsp a part of RoarAudio,
 *  a cross-platform sound system for both, home and professional use.
 *  See README for details.
 *
 *  This file is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 3
 *  as published by the Free Software Foundation.
 *
 *  libroardsp 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 software; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include "libroardsp.h"

ssize_t roar_dtmf_mus2samples(const int_least32_t t, const uint32_t rate) {
 int64_t ret = t;

 if ( t < 0 || rate == 0 ) {
  roar_err_set(ROAR_ERROR_INVAL);
  return -1;
 }

 ret *= (int64_t)rate;
 ret /= (int64_t)1000000;

 return ret;
}

int roar_dtmf_break(int16_t * samples, const size_t len, const uint32_t rate, const int options) {
 (void)rate, (void)options;

 ROAR_DBG("roar_dtmf_break(samples=%p, len=%llu, rate=%lu, options=%i) = ?", samples, (long long unsigned int)len, (long unsigned int)rate, options);

 if ( samples == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 memset(samples, 0, len*sizeof(int16_t));

 return 0;
}

static const struct tone {
 const uint16_t c;
 const float f0;
 const float f1;
} _roardsp_tones[] = {
 {'1', 697, 1209},
 {'2', 697, 1336},
 {'3', 697, 1477},
 {'A', 697, 1633},

 {'4', 770, 1209},
 {'5', 770, 1336},
 {'6', 770, 1477},
 {'B', 770, 1633},

 {'7', 852, 1209},
 {'8', 852, 1336},
 {'9', 852, 1477},
 {'C', 852, 1633},

 {'*', 941, 1209},
 {'0', 941, 1336},
 {'#', 941, 1477},
 {'D', 941, 1633},

 {0, -1, -1}
};

static const struct tone * __lookup_tone(const int options, uint16_t c) {
 size_t i;

 (void)options;

 if ( c >= 'a' )
  c -= 'a' - 'A';

 for (i = 0; _roardsp_tones[i].c != 0; i++) {
  if ( _roardsp_tones[i].c == c ) {
   return &(_roardsp_tones[i]);
  }
 }

 roar_err_set(ROAR_ERROR_NOENT);
 return NULL;
}

int roar_dtmf_tone (int16_t * samples, const size_t len, const uint32_t rate, const int options, const uint16_t c) {
 const struct tone * ct = NULL;
 size_t i;
 float t;
 float t_inc = 1./rate;
 float fc0, fc1;

 ROAR_DBG("roar_dtmf_tone(samples=%p, len=%llu, rate=%lu, options=%i, c=%i) = ?", samples, (long long unsigned int)len, (long unsigned int)rate, options, (int)c);

 if ( samples == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 ct = __lookup_tone(options, c);

 if ( ct == NULL ) {
  roar_err_set(ROAR_ERROR_NOENT);
  return -1;
 }

 fc0 = 2. * M_PI * ct->f0;
 fc1 = 2. * M_PI * ct->f1;

// memset(samples, 0, len);

 for (i = 0, t = 0.; i < len; t += t_inc, i++) {
  samples[i] = (sinf(fc0*t) + sinf(fc1*t))*8192.0;
 }

 return 0;
}


//ll