/**************************************************************************/
/*                            File: hmm_state.h                           */
/**************************************************************************/
/* Project: Continuous Speech Recognition Search Algorithms               */
/* Author: Neeraj Deshmukh, Aravind Ganapathiraju                         */
/* Class: EE 8993 Spring 1996                        Date: March 12, 1996 */
/**************************************************************************/

/*========================================================================
  This file declares the HMM state class that models the various phonemes
  (triphones) for the EE 8993 speech recognizer
  ========================================================================*/

/*------------------------------------------------------------------------
  make sure definitions are only made once
  ------------------------------------------------------------------------*/
#ifndef __ISIP_HMM_STATE
#define __ISIP_HMM_STATE

/*------------------------------------------------------------------------
  system and ISIP include files
  ------------------------------------------------------------------------*/
#include "hmm_matrix.h"
#include "linked_list.h"
#include <math/integral/integral.h>

/*------------------------------------------------------------------------
  forward declaration of classes
  ------------------------------------------------------------------------*/
class HMM_Matrix;
class HMM_Trans_State;
class Linked_List;
class HMM_State;
/*------------------------------------------------------------------------
  forward declaration of constants
  ------------------------------------------------------------------------*/
#define SEED_SELF_TRANS_SCORE    0.1
#define SEED_NEXT_TRANS_SCORE    0.9
#define MIN_SCORE                0.00001

/*========================================================================
  HMM_State
  class definition for the states of an HMM
  ========================================================================*/
class HMM_State : public Linked_List{
  
  // members
  //
protected:
  
  /*--------------------------------
    elements of the state transition
    --------------------------------*/
  float_4 init_state_prob_d;
  
  /*----------------------------
    elements of the state output
    ----------------------------*/
  String    out_symbol_d;
  
  /*-------------------------
    elements of the state pdf
    -------------------------*/
  HMM_Matrix **mean_vector_ptr;
  HMM_Matrix **covar_matrix_ptr;
  int_2      num_mixtures_d;
  float_4    *coeff_mixtures_d;

  // methods
  //
public:

  /*---------------------------
    constructors and destructor
    ---------------------------*/
  // default constructor
  //
  HMM_State (HMM_Trans_State *trans_ptr = NULL, HMM_Matrix **mean_vec_l = NULL,
	     HMM_Matrix **covar_mat_l = NULL, int_2 num_mix_l = 1,
	     String out_name = "");
  
  // destructor
  //
  ~HMM_State ();
  
  /*---------------------------------------
    input / output methods including scoring
    ----------------------------------------*/
  float_8 get_trans_prob_cc (String trans_state_name);
  void add_trans_state_cc (HMM_State *next_state_l, float_8 score);
  void set_out_symbol_cc (String out_name_l);
  String get_out_symbol_cc ();
  HMM_Trans_State *get_transition_cc();
  float_4 state_score_cc (HMM_Matrix *test_vector_l);


  // mixture related operations
  //
  void set_num_mix_cc (int_2 num_mix_l);
  int_2 get_num_mix_cc ();
    
  /*------------------------------
    parameter reestimation methods
    ------------------------------*/
  void update_mean_cc (HMM_Matrix **update_mean_l);
  void update_covariance_cc (HMM_Matrix **update_covar_l);
  void update_mix_weights_cc (float_4 *update_wts_l);
  HMM_Matrix **get_mean_cc ();
  HMM_Matrix **get_covar_cc ();

 /*-------------------------
    state linked list methods
    -------------------------*/
  HMM_State *get_next_state_cc ();
  HMM_State *get_prev_state_cc ();
  HMM_State *add_state_cc (String state_name, 
			   HMM_Trans_State *trans_ptr = NULL);
  HMM_State *find_state_cc (String state_name);

};

/*========================================================================
  Trans_State
  class definition for the state transitions of the grammar derived from 
  the generic linked list class
  ========================================================================*/

class HMM_Trans_State : public Linked_List {

  // members
  //
protected:

  float_8 trans_prob_d;

  // methods
  //
public:

 /*--------------------------
    constructor and destructor
    --------------------------*/
  HMM_Trans_State (HMM_State *state_ptr = NULL, float_8 score = 0);
  ~HMM_Trans_State ();
  
  /*----------------------
    input / output methods
    ----------------------*/
  String   get_state_name_cc ();
  float_8  get_transition_score_cc (String trans_state_name = NULL);

  /*------------------------------------
    state transition linked list methods
    ------------------------------------*/
  HMM_Trans_State *get_next_transition_cc ();
  HMM_Trans_State *get_prev_transition_cc ();
  HMM_Trans_State *find_transition_cc (String trans_state_name);
  HMM_Trans_State *add_transition_state_cc (HMM_State *state_ptr,
					    float_8 score);
};


#endif