/**************************************************************************/
/*                            File: hmm_model.cc                          */
/**************************************************************************/
/* Project: Continuous Speech Recognition Search Algorithms               */
/* Author: Neeraj Deshmukh, Aravind Ganapathiraju                         */
/* Class: EE 8993 Spring 1996                         Date: April 1, 1996 */
/**************************************************************************/

/*========================================================================
  This file defines the HMM  class methods that model the various phonemes
  (triphones) for the EE 8993 speech recognizer
  ========================================================================*/

/*------------------------------------------------------------------------
  system and ISIP include files
  ------------------------------------------------------------------------*/
#include "hmm_model.h"
#include "hmm_state.h"
#include "hmm_matrix.h"

/*------------------------------------------------------------------------
  forward declaration of classes
  ------------------------------------------------------------------------*/

class HMM_Model;
class HMM_State;
class HMM_Matrix;
class HMM_Trans_State;

/*------------------------------------------------------------------------
  Constructors and Destructors
  ------------------------------------------------------------------------*/

// create hmm, initialize model parameters from file.
//
HMM_Model :: HMM_Model ( String model_symbol_l, int_2 num_of_states_l)
{
  num_of_states_d = num_of_states_l;
  states = new HMM_State ();
  model_symbol_d = model_symbol_l;
}

// destructor
//
HMM_Model :: ~HMM_Model ()
{
  // free memory
  //
  delete states;
  delete model_symbol_d;  
}

/*-------------------------------------------
  I/O methods
  -------------------------------------------*/
// set the model output symbol to the specified character
//
void HMM_Model :: set_model_symbol_cc ( String model_symbol_l )
{
  // free memory asociated with old string
  //
  delete [] model_symbol_d;
  
  // allot appropriate memory block
  //
  model_symbol_d = new char[strlen (model_symbol_l) + 1];
  
  // now copy string over
  //
  strcpy (model_symbol_d, model_symbol_l);
}

// get the model output symbol
//
String HMM_Model :: get_model_symbol_cc ()
{
  return (model_symbol_d);
}

//set the number of states in the model
//
void HMM_Model :: set_num_of_states_cc ( int_2 num_of_states_l )
{
  num_of_states_d = num_of_states_l;
}

// get the score of a specified transition
//
float_8 HMM_Model :: get_trans_score_cc (String from_state_name,
					 String to_state_name )
{  
  HMM_State *curr_state= states->find_state_cc( from_state_name );
  return (curr_state->get_trans_prob_cc ( to_state_name ));
}

// add a new state to existing list of states in the model
//
HMM_State *HMM_Model::add_state_cc ( String state_name )
{
  return ( states->add_state_cc (state_name) );
}


// get the states of the model
//
HMM_State *HMM_Model :: get_states_cc ()
{
  return ( states );
}
  
// get the start state of the model
//
HMM_State *HMM_Model :: get_start_state_cc ()
{
  HMM_State *temp_state;
  for ( temp_state = states->get_next_state_cc ();
	temp_state->get_next_state_cc () != NULL;
	temp_state = temp_state->get_next_state_cc ())
    {
    }
  return (temp_state);
}

// get the stop state of the model
//
HMM_State *HMM_Model :: get_stop_state_cc ()
{
  return (states->get_next_state_cc ());
}