/***************************************************************************
 *   Copyright (C) 2005-2008 by the FIFE team                              *
 *   http://www.fifengine.de                                               *
 *   This file is part of FIFE.                                            *
 *                                                                         *
 *   FIFE is free software; you can redistribute it and/or                 *
 *   modify it under the terms of the GNU Lesser General Public            *
 *   License as published by the Free Software Foundation; either          *
 *   version 2.1 of the License, or (at your option) any later version.    *
 *                                                                         *
 *   This library 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     *
 *   Lesser General Public License for more details.                       *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this library; if not, write to the                 *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA          *
 ***************************************************************************/

// Standard C++ library includes
#include <algorithm>
#include <cassert>

// 3rd party library includes
#include <SDL.h>

// FIFE includes
// These includes are split up in two parts, separated by one empty line
// First block: files included from the FIFE root src directory
// Second block: files included from the same folder
#include "util/log/logger.h"

#include "timeevent.h"
#include "timemanager.h"

namespace FIFE {
	static const unsigned long UNDEFINED_TIME_DELTA = 999999;
	static Logger _log(LM_UTIL);
	
	TimeManager::TimeManager():
		m_current_time (0),
		m_time_delta(UNDEFINED_TIME_DELTA),
		m_average_frame_time(0) {
	}

	TimeManager::~TimeManager() {
	}

	void TimeManager::update() {
		// if first update...
		double avg_multiplier = 0.985;
		if (m_current_time == 0) {
			m_current_time = SDL_GetTicks();
			avg_multiplier = 0;
			m_time_delta = 0;
		} else {
			m_time_delta = m_current_time;
			m_current_time = SDL_GetTicks();
			m_time_delta = m_current_time - m_time_delta;
		}
		m_average_frame_time = m_average_frame_time * avg_multiplier +
			double(m_time_delta) * (1.0 - avg_multiplier);

		// Update live events.
		//
		// It is very important to NOT use iterators (over a vector)
		// here, as an event might add enough events to resize the vector.
		// -> Ugly segfault
		for (size_t i = 0; i < m_events_list.size(); ++i) {
			TimeEvent* event = m_events_list[ i ];
			if( event ) {
				event->managerUpdateEvent(m_current_time);
			}
		}

		// Remove dead events
		std::vector<TimeEvent*>::iterator it;
		it = std::remove( m_events_list.begin(), m_events_list.end(), static_cast<TimeEvent*>(0));
		m_events_list.erase( it, m_events_list.end());
	}

	void TimeManager::registerEvent(TimeEvent* event) {
		// Register.
		m_events_list.push_back(event);
	}

	void TimeManager::unregisterEvent(TimeEvent* event) {
		// Unregister.
		for (size_t i = 0; i < m_events_list.size(); ++i) {
			TimeEvent*& event_i = m_events_list[ i ];
			if( event_i == event) {
				event_i = 0;
				return;
			}
		}
	}

	unsigned long TimeManager::getTime() const {
		return m_current_time;
	}

	unsigned long TimeManager::getTimeDelta() const {
		return m_time_delta;
	}

	double TimeManager::getAverageFrameTime() const {
		return m_average_frame_time;
	}

	void TimeManager::printStatistics() const {
		FL_LOG(_log, LMsg("Timers: ") << m_events_list.size());
	}

} //FIFE