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

/*

 * Copyright 2007,2011 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.

 */

#ifndef INCLUDED_DIGITAL_OFDM_FRAME_SINK_H

#define INCLUDED_DIGITAL_OFDM_FRAME_SINK_H

#include <gr_sync_block.h>

#include <gr_msg_queue.h>

class digital_ofdm_frame_sink;

typedef boost::shared_ptr<digital_ofdm_frame_sink> digital_ofdm_frame_sink_sptr;

digital_ofdm_frame_sink_sptr 

digital_make_ofdm_frame_sink (const std::vector<gr_complex> &sym_position, 

                              const std::vector<unsigned char> &sym_value_out,

                              gr_msg_queue_sptr target_queue, unsigned int occupied_tones,

                              float phase_gain=0.25, float freq_gain=0.25*0.25/4.0);

/*!

 * \brief Takes an OFDM symbol in, demaps it into bits of 0's and 1's, packs

 * them into packets, and sends to to a message queue sink.

 * \ingroup sink_blk

 * \ingroup ofdm_blk

 *

 * NOTE: The mod input parameter simply chooses a pre-defined demapper/slicer. Eventually,

 * we want to be able to pass in a reference to an object to do the demapping and slicing

 * for a given modulation type.

 */

class digital_ofdm_frame_sink : public gr_sync_block

{

  friend digital_ofdm_frame_sink_sptr 

  digital_make_ofdm_frame_sink (const std::vector<gr_complex> &sym_position, 

                                const std::vector<unsigned char> &sym_value_out,

                                gr_msg_queue_sptr target_queue, unsigned int occupied_tones,

                                float phase_gain, float freq_gain);

 private:

  enum state_t {STATE_SYNC_SEARCH, STATE_HAVE_SYNC, STATE_HAVE_HEADER};

  static const int MAX_PKT_LEN    = 4096;

  static const int HEADERBYTELEN   = 4;

  gr_msg_queue_sptr  d_target_queue;                // where to send the packet when received

  state_t            d_state;

  unsigned int       d_header;                        // header bits

  int                     d_headerbytelen_cnt;        // how many so far

  unsigned char      *d_bytes_out;              // hold the current bytes produced by the demapper    

  unsigned int       d_occupied_carriers;

  unsigned int       d_byte_offset;

  unsigned int       d_partial_byte;

  unsigned char      d_packet[MAX_PKT_LEN];        // assembled payload

  int                      d_packetlen;                // length of packet

  int                d_packet_whitener_offset;  // offset into whitener string to use

  int                     d_packetlen_cnt;                // how many so far

  gr_complex * d_derotated_output;  // Pointer to output stream to send deroated symbols out

  std::vector<gr_complex>    d_sym_position;

  std::vector<unsigned char> d_sym_value_out;

  std::vector<gr_complex>    d_dfe;

  unsigned int d_nbits;

  unsigned char d_resid;

  unsigned int d_nresid;

  float d_phase;

  float d_freq;

  float d_phase_gain;

  float d_freq_gain;

  float d_eq_gain;

  std::vector<int> d_subcarrier_map;

 protected:

  digital_ofdm_frame_sink(const std::vector<gr_complex> &sym_position, 

                          const std::vector<unsigned char> &sym_value_out,

                          gr_msg_queue_sptr target_queue, unsigned int occupied_tones,

                          float phase_gain, float freq_gain);

  void enter_search();

  void enter_have_sync();

  void enter_have_header();

  bool header_ok()

  {

    // confirm that two copies of header info are identical

    return ((d_header >> 16) ^ (d_header & 0xffff)) == 0;

  }

  unsigned char slicer(const gr_complex x);

  unsigned int demapper(const gr_complex *in,

                        unsigned char *out);

  bool set_sym_value_out(const std::vector<gr_complex> &sym_position, 

                         const std::vector<unsigned char> &sym_value_out);

 public:

  ~digital_ofdm_frame_sink();

  int work(int noutput_items,

           gr_vector_const_void_star &input_items,

           gr_vector_void_star &output_items);

};

#endif /* INCLUDED_GR_OFDM_FRAME_SINK_H */