/*

 * Copyright 2006 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 2, 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_PAGER_FLEX_SYNC_H

#define INCLUDED_PAGER_FLEX_SYNC_H

#include <gr_block.h>

class pager_flex_sync;

typedef boost::shared_ptr<pager_flex_sync> pager_flex_sync_sptr;

typedef std::vector<gr_int64> gr_int64_vector;

pager_flex_sync_sptr pager_make_flex_sync(int rate);

/*!

 * \brief flex sync description

 * \ingroup block

 */

class pager_flex_sync : public gr_block

{

private:

    // Constructors

    friend pager_flex_sync_sptr pager_make_flex_sync(int rate);

    pager_flex_sync(int rate);

    // State machine transitions

    void enter_idle();

    void enter_syncing();

    void enter_sync1();

    void enter_sync2();

    void enter_data();

    int index_avg(int start, int end);

    bool test_sync(unsigned char sym);

    void parse_fiw();

    int output_symbol(unsigned char sym);    

    // Simple state machine

    enum state_t { ST_IDLE, ST_SYNCING, ST_SYNC1, ST_SYNC2, ST_DATA };

    state_t d_state;     

    int d_rate;     // Incoming sample rate

    int d_index;    // Index into current baud

    int d_start;    // Start of good sync 

    int d_center;   // Center of bit

    int d_end;      // End of good sync

    int d_count;    // Bit counter

    int d_mode;     // Current packet mode

    int d_baudrate; // Current decoding baud rate

    int d_levels;   // Current decoding levels

    int d_spb;      // Current samples per baud

    bool d_hibit;   // Alternating bit indicator for 3200 bps

    gr_int32 d_fiw; // Frame information word

    int d_frame;    // Current FLEX frame

    int d_cycle;    // Current FLEX cycle

    int d_unknown1;

    int d_unknown2;

    unsigned char d_bit_a;

    unsigned char d_bit_b;

    unsigned char d_bit_c;

    unsigned char d_bit_d;

    unsigned char *d_phase_a;  

    unsigned char *d_phase_b;

    unsigned char *d_phase_c;

    unsigned char *d_phase_d;

    gr_int64_vector d_sync; // Trial synchronizers

public:

    void forecast(int noutput_items, gr_vector_int &inputs_required);

    int general_work(int noutput_items,

                     gr_vector_int &ninput_items,

                     gr_vector_const_void_star &input_items, 

                     gr_vector_void_star &output_items);

};

#endif /* INCLUDED_PAGER_FLEX_SYNC_H */