/* -*- c++ -*- */
/*
 * Copyright 2004,2007,2008,2010 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_fft_vcc_fftw.h>
#include <gr_io_signature.h>
#include <gri_fft.h>
#include <math.h>
#include <string.h>

gr_fft_vcc_sptr
gr_make_fft_vcc_fftw (int fft_size, bool forward,
		      const std::vector<float> &window,
		      bool shift, int nthreads)
{
  return gnuradio::get_initial_sptr(new gr_fft_vcc_fftw
				    (fft_size, forward, window,
				     shift, nthreads));
}

gr_fft_vcc_fftw::gr_fft_vcc_fftw (int fft_size, bool forward,
				  const std::vector<float> &window,
				  bool shift, int nthreads)
  : gr_fft_vcc("fft_vcc_fftw", fft_size, forward, window, shift)
{
  d_fft = new gri_fft_complex (d_fft_size, forward, nthreads);
}

gr_fft_vcc_fftw::~gr_fft_vcc_fftw ()
{
  delete d_fft;
}

void
gr_fft_vcc_fftw::set_nthreads(int n)
{
  d_fft->set_nthreads(n);
}

int
gr_fft_vcc_fftw::nthreads() const
{
  return d_fft->nthreads();
}

int
gr_fft_vcc_fftw::work (int noutput_items,
		  gr_vector_const_void_star &input_items,
		  gr_vector_void_star &output_items)
{
  const gr_complex *in = (const gr_complex *) input_items[0];
  gr_complex *out = (gr_complex *) output_items[0];

  unsigned int input_data_size = input_signature()->sizeof_stream_item (0);
  unsigned int output_data_size = output_signature()->sizeof_stream_item (0);

  int count = 0;

  while (count++ < noutput_items){

    // copy input into optimally aligned buffer

    if (d_window.size()){
      gr_complex *dst = d_fft->get_inbuf();
      if(!d_forward && d_shift){
        unsigned int offset = (!d_forward && d_shift)?(d_fft_size/2):0;
        int fft_m_offset = d_fft_size - offset;
        for (unsigned int i = 0; i < offset; i++)		// apply window
            dst[i+fft_m_offset] = in[i] * d_window[i];
        for (unsigned int i = offset; i < d_fft_size; i++)		// apply window
            dst[i-offset] = in[i] * d_window[i];
      } else {
        for (unsigned int i = 0; i < d_fft_size; i++)		// apply window
          dst[i] = in[i] * d_window[i];
      }
    }
    else {
      if(!d_forward && d_shift) {  // apply an ifft shift on the data
	gr_complex *dst = d_fft->get_inbuf();
	unsigned int len = (unsigned int)(floor(d_fft_size/2.0)); // half length of complex array
	memcpy(&dst[0], &in[len], sizeof(gr_complex)*(d_fft_size - len));
	memcpy(&dst[d_fft_size - len], &in[0], sizeof(gr_complex)*len);
      }
      else {
	memcpy (d_fft->get_inbuf(), in, input_data_size);
      }
    }

    // compute the fft
    d_fft->execute ();

    // copy result to our output
    if(d_forward && d_shift) {  // apply a fft shift on the data
      unsigned int len = (unsigned int)(ceil(d_fft_size/2.0));
      memcpy(&out[0], &d_fft->get_outbuf()[len], sizeof(gr_complex)*(d_fft_size - len));
      memcpy(&out[d_fft_size - len], &d_fft->get_outbuf()[0], sizeof(gr_complex)*len);
    }
    else {
      memcpy (out, d_fft->get_outbuf (), output_data_size);
    }

    in  += d_fft_size;
    out += d_fft_size;
  }

  return noutput_items;
}