/**
 * @file artis/observer/View.hpp
 * @author See the AUTHORS file
 */

/*
 * Copyright (C) 2012-2017 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_VIEW_HPP
#define ARTIS_OBSERVER_VIEW_HPP

#include <artis/kernel/AbstractModel.hpp>
#include <artis/utils/DoubleTime.hpp>

#include <boost/lexical_cast.hpp>

namespace artis { namespace observer {

template < typename U, typename V >
class View
{
    typedef std::vector < unsigned int > Selector;

public:
    typedef std::vector < std::pair < double, std::string > > Value;
    typedef std::map < std::string, Value > Values;

    View() : _model(0)
    { }

    virtual ~View()
    { }

    void attachModel(const artis::kernel::AbstractModel < U, V >* m)
    { _model = m; }

    double begin() const
    {
        double t = utils::DoubleTime::infinity;

        for (Values::const_iterator it = _values.begin(); it!= _values.end();
             ++it) {
            if (t > it->second.begin()->first) {
                t = it->second.begin()->first;
            }
        }
        return t;
    }

    View* clone() const
    {
        View* v = new View();

        v->_selectors = _selectors;
        for (Values::const_iterator it = _values.begin(); it!= _values.end();
             ++it) {

            v->_values[it->first] = Value();
            Value::const_iterator itp = it->second.begin();

            while (itp != it->second.end()) {
                v->_values[it->first].push_back(*itp);
                ++itp;
            }
        }
        v->_model = 0;
        return v;
    }

    double end() const
    {
        double t = 0;

        for (Values::const_iterator it = _values.begin(); it!= _values.end();
             ++it) {
            if (t < it->second.back().first) {
                t = it->second.back().first;
            }
        }
        return t;
    }

    double get(double t, const std::string& name) const
    {
        Values::const_iterator it = _values.find(name);

        if (it != _values.end()) {
            Value::const_iterator itp = it->second.begin();

            while (itp != it->second.end() and itp->first < t) {
                ++itp;
            }
            if (itp != it->second.end()) {
                // TODO: to improve
                return boost::lexical_cast < double >(itp->second);
            } else {
                return 0;
            }
        }
        return 0;
    }

    const Value& get(const std::string& name) const
    {
        Values::const_iterator it = _values.find(name);

        if (it != _values.end()) {
            return it->second;
        } else {
            assert(false);
        }
    }

    virtual void observe(double time)
    {
        for (typename Selectors::const_iterator it = _selectors.begin();
             it != _selectors.end(); ++it) {
            const kernel::Node < utils::DoubleTime >* model = _model;

            if (it->second.second.size() > 1) {
                size_t i = 0;

                while (i < it->second.second.size() - 1 and model) {
                    model = model->get_submodel(it->second.second[i]);
                    ++i;
                }
            }
            if (model) {
                _values[it->first].push_back(
                    std::make_pair(time,
                                   model->get(it->second.first, time,
                                              it->second.second.back())));
            }
        }
    }

    void selector(const std::string& name, kernel::ValueTypeID value_type,
                  const Selector& chain)
    {
        _selectors[name] = std::make_pair(value_type, chain);
        _values[name] = Value();
    }

    const Values& values() const
    { return _values;}

private:
    typedef std::map < std::string, std::pair < kernel::ValueTypeID,
                                                Selector > > Selectors;

    Selectors                                    _selectors;
    Values                                       _values;
    const artis::kernel::AbstractModel < U, V >* _model;
};

} }

#endif