artis-star/src/artis-star/common/observer/Observer.hpp

/**
 * @file common/observer/Observer.hpp
 * @author The ARTIS Development Team
 * See the AUTHORS or Authors.txt file
 */

/*
 * ARTIS - the multimodeling and simulation environment
 * This file is a part of the ARTIS environment
 *
 * Copyright (C) 2013-2022 ULCO http://www.univ-littoral.fr
 *
 * This program 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef ARTIS_OBSERVER_OBSERVER_HPP
#define ARTIS_OBSERVER_OBSERVER_HPP

#include <artis-star/common/Model.hpp>
#include <artis-star/common/observer/View.hpp>

#include <vector>

namespace artis::common::observer {

template<typename Time>
class Observer {
public:
  typedef std::map<std::string, View<Time> *> Views;

  Observer(const common::Model<Time> *model)
    : _step(0), _model(model), _last_time(0), _init(false) {}

  virtual ~Observer() {
    for (typename Views::iterator it = _views.begin(); it != _views.end(); ++it) {
      delete it->second;
    }
  }

  void attachView(const std::string &name, View<Time> *view) {
    _views[name] = view;
    view->attachModel(_model);
  }

  void clear() {
    for (typename Views::iterator it = _views.begin(); it != _views.end(); ++it) {
      it->second->clear();
    }
  }

  Views *cloneViews() const {
    auto view = new Views();

    for (typename Views::const_iterator it = _views.begin();
         it != _views.end(); ++it) {
      (*view)[it->first] = it->second->clone();
    }
    return view;
  }

  const View<Time> &view(const std::string &name) const {
    return *_views.find(name)->second;
  }

  const Views &views() const { return _views; }

  void init() { }

  void observe(double t, double next_t, bool finish) {
    if (_step == 0) {
      observe(t);
      _last_time = t;
    } else {
      if (not _init) {
        observe(t);
        _last_time = t;
        _init = true;
      }

      double next_last_time = std::floor((_last_time + _step + epsilon) / _step) * _step;

      if (t <= next_last_time and (next_t > next_last_time or finish)) {
        do {
          observe(next_last_time);
          _last_time = next_last_time;
          next_last_time = std::floor((_last_time + _step + epsilon) / _step) * _step;
        } while (t < next_last_time and next_t > next_last_time);
      }
    }
  }

  void switch_to_timed_observer(double step) {

    assert(step > 0);

    _step = step;
  }

private:
  void observe(double t) {
    for (typename Views::iterator it = _views.begin(); it != _views.end();
         ++it) {
      it->second->observe(t, _step == 0);
    }
  }

  const double epsilon = 1e-6;

  double _step;
  const common::Model<Time> *_model;
  Views _views;
  double _last_time;
  bool _init;
};

}

#endif