// file: hmm.h
//
// this file defines a class the implements a discrete hmm
//

// make sure definitions are only made once
//
#ifndef __ISIP_HMM
#define __ISIP_HMM

// system include files
//
#include <stdio.h>

// isip include files
//
#include "integral.h"

//-----------------------------------------------------------------------------
//
// Hmm: a class that implements a discrete hmm
//
// the notation in this code closely parallels the following textbook:
//
//  J.R. Deller, Jr., J.G. Proakis, and J.H.L. Hansen,
//  Discrete-Time Processing of Speech Signals,
//  MacMillan, 1993, ISBN: 0-02-328301-7.
//
// specifically, see Section 12.2.2, starting on page 684.
//
//-----------------------------------------------------------------------------
class Hmm {

  //---------------------------------------------------------------------------
  //
  // protected data
  //
  //---------------------------------------------------------------------------
protected:
 
  // parameters of a discrete hmm
  //
  int_4 S;
  int_4 K;
  char_1* y;
  float_4** a;
  float_4** b;
  float_4* pi;

  // parameters used to update an hmm using the viterbi algorithm
  //
  float_4** a_new;
  float_4** b_new;
  float_4* pi_new;

  //---------------------------------------------------------------------------
  //
  // public methods
  //
  //---------------------------------------------------------------------------
public:

  // cstr: constructors/destructors
  //
  Hmm();
  ~Hmm();

  // cmdl: command line processing
  //
  logical_1 get_parameters_cc(int argc, char** argv,
			      int_4& S, int_4& K, int_4& P, int_4& L,
			      int_4& mode, int_4& alg, int_4& debug,
			      char_1* file1, char_1* file2);
  volatile void help_cc();

  // io: i/o of data and models
  //
  logical_1 load_cc(char_1* file);
  logical_1 convert_cc(int_4* O, int_4& T,
		       char_1* O_buffer, char_1* line_bufer);
  logical_1 save_cc(char_1* fname);

  // disp: display methods
  //
  logical_1 display_cc(FILE* fp);
  logical_1 display_symbol_table_cc(FILE* fp);
  logical_1 display_sequence_info_cc(int_4 seq_num, float_4 seq_prob,
				     int_4 T, char_1* O_sym, int_4* O,
				     int_4* x, int_4 debug, FILE* fp);

  // init: initialization
  //
  logical_1 init_cc(int_4 S, int_4 K);
  logical_1 init_counters_cc();
  logical_1 seed_cc();

  // test: test-related methods
  //
  float_4 test_cc(int_4* x, int_4* O, int_4 T, int_4 alg, int_4 debug);
  float_4 test_viterbi_cc(int_4* x, int_4* O, int_4 T, int_4 debug);
  float_4 test_baumwelch_cc(int_4* x, int_4* O, int_4 T, int_4 debug);

  // train: train-related methods
  //
  logical_1 train_symbol_table_cc(FILE* fp);
  float_4 train_cc(int_4* x, int_4* O, int_4 T, int_4 alg, int_4 debug);
  logical_1 replace_cc(int_4 alg);

  logical_1 train_viterbi_cc(int_4* x, int_4* O, int_4 T, int_4 debug);
  logical_1 replace_viterbi_cc();

  float_4 train_baumwelch_cc(int_4* x, int_4* O, int_4 T, int_4 debug);
  logical_1 replace_baumwelch_cc();

  // generate: generate data from a model
  //
  float_4 generate_cc(int_4& T, char_1* O_sym, int_4* O, int_4* x);

  //---------------------------------------------------------------------------
  //
  // private methods
  //
  //---------------------------------------------------------------------------
private:

  // oper: simple operators
  //
  float_4 log10_cc(float_4 value);
  float_4 inv_log10_cc(float_4 value);
  float_4 invert_cc(float_4 value);
  int_4 match_cc(char_1 val);

  // mem: memory allocation
  //
  logical_1 cleanup_cc();
  logical_1 allocate_cc(int_4 S, int_4 K);

  logical_1 cleanup_counters_cc();
  logical_1 allocate_counters_cc();

  // generate: random number generation
  //
  int_4 generate_node_cc(float_4* v, int_4 nv);

  //
  // end of class
};

//
// end of include file
#endif