/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
**]  All rights reserved.
*
* vi:ts=4 sw=4 tw=75
*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
**************************************************************************/

#ifndef _MOOF_TIMER_HH_
#define _MOOF_TIMER_HH_

/**
 * @file Timer.hh
 * Functions for measuring time in a friendly unit.
 */

#include <map>

#include <boost/bind.hpp>
#include <boost/function.hpp>

#include <Moof/Math.hh>


namespace Mf {


class Timer
{
public:

	enum Mode
	{
		INVALID		= -1,
		NORMAL		=  0,
		ACTUAL		=  1,
		REPEAT		=  2
	};

	typedef boost::function<void(Timer&,Scalar)> Function;


	Timer() :
		mMode(INVALID) {}

	Timer(const Function& function, Scalar seconds, Mode mode = NORMAL)
	{
		init(function, seconds, mode);
	}

	~Timer()
	{
		invalidate();
	}

	void init(const Function& function, Scalar seconds,
			  Mode mode = NORMAL);

	bool isValid() const;
	void invalidate();

	void fire();

	Scalar getSecondsRemaining() const;
	bool isExpired() const;
	bool isRepeating() const;


	/**
	 * Get the number of seconds since a fixed, arbitrary point in the
	 * past.
	 * @return Seconds.
	 */

	static Scalar getTicks();


	/**
	 * Put the thread to sleep for a certain period of time.  If absolute
	 * is true, then it will sleep until seconds after the fixed time in
	 * the past.  If absolute is false, it will sleep for seconds starting
	 * now.  Unlike system sleep functions, this one automatically resumes
	 * sleep if sleep was interrupted by a signal.  Therefore, calling this
	 * function is guaranteed to sleep for the requested amount of time
	 * (and maybe longer).
	 */

	static void sleep(Scalar seconds, Mode mode = NORMAL);


	static Scalar getNextFire()
	{
		return gNextFire;
	}

	static void fireIfExpired();
	static void fireIfExpired(Scalar t);

private:

	static unsigned getNewID();
	static Scalar findNextFire();

	Function	mFunction;
	Mode		mMode;
	Scalar		mAbsolute;
	Scalar		mInterval;
	unsigned	mId;

	static Scalar						gNextFire;
	static std::map<unsigned,Timer*>	gTimers;
};


} // namespace Mf

#endif // _MOOF_TIMER_HH_