/*
  This file is part of the FRED system.

  Copyright (c) 2010-2015, University of Pittsburgh, John Grefenstette,
  Shawn Brown, Roni Rosenfield, Alona Fyshe, David Galloway, Nathan
  Stone, Jay DePasse, Anuroop Sriram, and Donald Burke.

  Licensed under the BSD 3-Clause license.  See the file "LICENSE" for
  more information.
*/

//
//
// File: Intention.cc
//
#include "Intention.h"
#include "Global.h"
#include "Random.h"
#include "Utils.h"
#include "Person.h"
#include "Behavior.h"
#include "Perceptions.h"

Intention::Intention(Person * _self, int _index) {
  this->index = _index;
  this->self = _self;
  this->expiration = 0;
  this->params = Behavior::get_behavior_params(this->index);

  this->perceptions = NULL;

  // pick a behavior_change_model for this individual based on the population market shares
  this->behavior_change_model = Random::draw_from_distribution(this->params->behavior_change_model_cdf_size,
							       this->params->behavior_change_model_cdf);

  // set the other intention parameters based on the behavior_change_model
  switch(this->behavior_change_model) {

  case Behavior_change_model_enum::REFUSE:
    this->intention = false;
    this->probability = 0.0;
    this->frequency = 0;
    break;

  case Behavior_change_model_enum::ACCEPT:
    this->intention = true;
    this->probability = 1.0;
    this->frequency = 0;
    break;

  case Behavior_change_model_enum::FLIP:
    this->probability = Random::draw_random(this->params->min_prob, this->params->max_prob);
    this->intention = (Random::draw_random()<= this->probability);
    this->frequency = this->params->frequency;
    break;

  case Behavior_change_model_enum::HBM:
    this->probability = Random::draw_random(this->params->min_prob, this->params->max_prob);
    this->intention = (Random::draw_random() <= this->probability);
    this->frequency = this->params->frequency;
    setup_hbm();
    break;

  default: // REFUSE
    this->intention = false;
    this->probability = 0.0;
    this->frequency = 0;
    break;
  }

  FRED_VERBOSE(1,
	       "created INTENTION %d name %d behavior_change_model %d freq %d expir %d probability %f\n",
	       this->index, this->params->name, this->behavior_change_model, this->frequency,
	       this->expiration, this->probability);
}

void Intention::update(int day) {
  FRED_VERBOSE(1,
	       "update INTENTION %s day %d behavior_change_model %d freq %d expir %d probability %f\n",
	       this->params->name, day, this->behavior_change_model, this->frequency,
	       this->expiration, this->probability);

  if(this->frequency > 0 && this->expiration <= day) {
    if(this->behavior_change_model == Behavior_change_model_enum::HBM && day > 0) {
      this->probability = update_hbm(day);
    }
    double r = Random::draw_random();
    this->intention = (r < this->probability);
    this->expiration = day + this->frequency;
  }

  FRED_VERBOSE(1, "updated INTENTION %s = %d  expir = %d\n", this->params->name,
	       (this->intention ? 1 : 0),
	       this->expiration);

}

////// HEALTH BELIEF MODEL

double Intention::update_hbm(int day) {
  int disease_id = 0;

  FRED_VERBOSE(1, "update_hbm entered: thresholds: sus= %f sev= %f  ben= %f bar = %f\n",
	       this->susceptibility_threshold, this->severity_threshold,
	       this->benefits_threshold, this->barriers_threshold);

  // update perceptions.
  this->perceptions->update(day);

  // each update is specific to current behavior
  double perceived_severity = (this->perceptions->get_perceived_severity(disease_id) > this->severity_threshold);

  double perceived_susceptibility = (this->perceptions->get_perceived_susceptibility(disease_id)
				     > this->susceptibility_threshold);

  double perceived_benefits = 1.0;
  double perceived_barriers = 0.0;

  // decide whether to act or not
  double odds;
  odds = this->params->base_odds_ratio;

  if(perceived_susceptibility == 1)
    odds *= this->params->susceptibility_odds_ratio;

  if(perceived_severity == 1)
    odds *= this->params->severity_odds_ratio;

  if(perceived_benefits == 1)
    odds *= this->params->benefits_odds_ratio;

  if(perceived_barriers == 1)
    odds *= this->params->barriers_odds_ratio;


  return (odds > 1.0);
}

void Intention::setup_hbm() {
  this->perceptions = new Perceptions(self);
  this->susceptibility_threshold = Random::draw_random(this->params->susceptibility_threshold_distr[0],
						       this->params->susceptibility_threshold_distr[1]);
  this->severity_threshold = Random::draw_random(this->params->severity_threshold_distr[0],
						 this->params->severity_threshold_distr[1]);
  this->benefits_threshold = Random::draw_random(this->params->benefits_threshold_distr[0],
						 this->params->benefits_threshold_distr[1]);
  this->barriers_threshold = Random::draw_random(this->params->barriers_threshold_distr[0],
						 this->params->barriers_threshold_distr[1]);
  FRED_VERBOSE(1, "setup_hbm: thresholds: sus= %f sev= %f  ben= %f bar = %f\n",
	       this->susceptibility_threshold, this->severity_threshold,
	       this->benefits_threshold, this->barriers_threshold);
}