/* -*- c++ -*- */

/*

 * Copyright 2007 Free Software Foundation, Inc.

 * 

 * This file is part of GNU Radio

 * 

 * GNU Radio 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 3, or (at your option)

 * any later version.

 * 

 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street,

 * Boston, MA 02110-1301, USA.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <gr_ofdm_sampler.h>

#include <gr_io_signature.h>

#include <gr_expj.h>

gr_ofdm_sampler_sptr

gr_make_ofdm_sampler (unsigned int fft_length, 

                      unsigned int symbol_length)

{

  return gr_ofdm_sampler_sptr (new gr_ofdm_sampler (fft_length, symbol_length));

}

gr_ofdm_sampler::gr_ofdm_sampler (unsigned int fft_length, 

                                  unsigned int symbol_length)

  : gr_block ("ofdm_sampler",

              gr_make_io_signature2 (2, 2, sizeof (gr_complex), sizeof(char)),

              gr_make_io_signature (1, 1, sizeof (gr_complex)*fft_length)),

    d_fft_length(fft_length), d_symbol_length(symbol_length)

{

}

void

gr_ofdm_sampler::forecast (int noutput_items, gr_vector_int &ninput_items_required)

{

  // FIXME do we need more

  int nreqd  = (noutput_items-1) * d_symbol_length + d_fft_length;

  unsigned ninputs = ninput_items_required.size ();

  for (unsigned i = 0; i < ninputs; i++)

    ninput_items_required[i] = nreqd;

}

int

gr_ofdm_sampler::general_work (int noutput_items,

                               gr_vector_int &ninput_items,

                               gr_vector_const_void_star &input_items,

                               gr_vector_void_star &output_items)

{

  gr_complex *iptr = (gr_complex *) input_items[0];

  char *trigger = (char *) input_items[1];

  gr_complex *optr = (gr_complex *) output_items[0];

  int found=0;

  int i=d_fft_length-1;

  while(!found && i<std::min(ninput_items[0],ninput_items[1]) ) {

    if(trigger[i])

      found = 1;

    else

      i++;

  }

  if(found) {

    assert(i-d_fft_length+1 >= 0);

    for(int j=i-d_fft_length+1;j<=i;j++)

      *optr++ = iptr[j];

    consume_each(i-d_fft_length+2);

    //printf("OFDM Sampler found:  ninput_items: %d/%d   noutput_items: %d  consumed: %d   found: %d\n", 

    //   ninput_items[0], ninput_items[1], noutput_items, (i-d_fft_length+2), found);

  }

  else {

    consume_each(i-d_fft_length+1);

    //printf("OFDM Sampler not found:  ninput_items: %d/%d   noutput_items: %d  consumed: %d   found: %d\n", 

    //  ninput_items[0], ninput_items[1], noutput_items, (i-d_fft_length+1), found);

 }

  return found;

}