/***************************************************************************
 *   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          *
 ***************************************************************************/

#ifndef FIFE_TIME_PROVIDER_H
#define FIFE_TIME_PROVIDER_H

// Standard C++ library includes

// 3rd party library includes

// 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/base/exception.h"

namespace FIFE {

	/** Timeprovider is an utility providing time management functionality
	 * You can have hierarchy of time providers, whose multiplier can be changed independently.
	 * Changing providers upper in the hierarchy, changes also all subproviders with the same ratio
	 */
	class TimeProvider {
	public:
		/** Constructor
		 * In case there there is no provider master, you can use NULL
		 */
		TimeProvider(TimeProvider* master);
		~TimeProvider();
		
		/** With multiplier, you can adjust the time speed. 0.5 means time runs half as slow,
		 * while 2.0 means it runs twice as fast
		 */
		void setMultiplier(float multiplier);
		
		/** @see setMultiplier. Returns mutliplier for this single provider
		 */
		float getMultiplier() const;
		
		/** @see setMultiplier. Returns mutliplier for whole chain of timeproviders
		 * E.g. if master has multiplier 2.0 and this has 0.5, end result = 1.0
		 */
		float getTotalMultiplier() const;
		
		/** Returns current game ticks. Fetched from furthest master to reduce system calls.
		 */
		unsigned int getGameTicks() const;
		
	private:
		TimeProvider* m_master;
		float m_multiplier;
	};
	
	/** Utility function to calculate time scaling. Mostly done to avoid littering other code
	 * with related casting
	 * @return multiplier * ticks
	 */
	unsigned int scaleTime(float multiplier, unsigned int ticks);

} //FIFE
#endif