/* -*- c++ -*- */
/*
 * Copyright 2011,2012 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 "constellation_receiver_cb_impl.h"
#include <gr_io_signature.h>
#include <gr_prefs.h>
#include <gr_math.h>
#include <gr_expj.h>
#include <stdexcept>

namespace gr {
  namespace digital {

#define M_TWOPI (2*M_PI)
#define VERBOSE_MM     0     // Used for debugging symbol timing loop
#define VERBOSE_COSTAS 0     // Used for debugging phase and frequency tracking

    constellation_receiver_cb::sptr 
    constellation_receiver_cb::make(constellation_sptr constell,
				    float loop_bw, float fmin, float fmax)
    {
      return gnuradio::get_initial_sptr
	(new constellation_receiver_cb_impl(constell, loop_bw,
					    fmin, fmax));
    }
 
    static int ios[] = {sizeof(char), sizeof(float), sizeof(float), sizeof(float), sizeof(gr_complex)};
    static std::vector<int> iosig(ios, ios+sizeof(ios)/sizeof(int));
    constellation_receiver_cb_impl::constellation_receiver_cb_impl(constellation_sptr constellation, 
								   float loop_bw, float fmin, float fmax)
      : gr_block("constellation_receiver_cb",
		 gr_make_io_signature(1, 1, sizeof(gr_complex)),
		 gr_make_io_signaturev(1, 5, iosig)),
	gri_control_loop(loop_bw, fmax, fmin),
	d_constellation(constellation),
	d_current_const_point(0)
    {
      if(d_constellation->dimensionality() != 1)
	throw std::runtime_error("This receiver only works with constellations of dimension 1.");
    }

    constellation_receiver_cb_impl::~constellation_receiver_cb_impl()
    {
    }

    void
    constellation_receiver_cb_impl::phase_error_tracking(float phase_error)
    {
      advance_loop(phase_error);
      phase_wrap();
      frequency_limit();
  
#if VERBOSE_COSTAS
      printf("cl: phase_error: %f  phase: %f  freq: %f  sample: %f+j%f  constellation: %f+j%f\n",
	     phase_error, d_phase, d_freq, sample.real(), sample.imag(), 
	     d_constellation->points()[d_current_const_point].real(),
	     d_constellation->points()[d_current_const_point].imag());
#endif
    }

    int
    constellation_receiver_cb_impl::general_work(int noutput_items,
						 gr_vector_int &ninput_items,
						 gr_vector_const_void_star &input_items,
						 gr_vector_void_star &output_items)
    {
      const gr_complex *in = (const gr_complex *)input_items[0];
      unsigned char *out = (unsigned char *)output_items[0];

      int i=0;

      float phase_error;
      unsigned int sym_value;
      gr_complex sample, nco;

      float *out_err = 0, *out_phase = 0, *out_freq = 0;
      gr_complex *out_symbol;
      if(output_items.size() == 5) {
	out_err = (float*)output_items[1];
	out_phase = (float*)output_items[2];
	out_freq = (float*)output_items[3];
	out_symbol = (gr_complex*)output_items[4];
      }

      while((i < noutput_items) && (i < ninput_items[0])) {
	sample = in[i];
	nco = gr_expj(d_phase);   // get the NCO value for derotating the current sample
	sample = nco*sample;      // get the downconverted symbol

	sym_value = d_constellation->decision_maker_pe(&sample, &phase_error);
	phase_error_tracking(phase_error);  // corrects phase and frequency offsets

	out[i] = sym_value;

	if(output_items.size() == 5) {
	  out_err[i] = phase_error;
	  out_phase[i] = d_phase;
	  out_freq[i] = d_freq;
	  out_symbol[i] = sample;
	}
	i++;
      }

      consume_each(i);
      return i;
    }

  } /* namespace digital */
} /* namespace gr */