/**
 * @file include/di/Timer.h
 * @brief Generic timer class
 * @date June 2, 2015
 * @author J.J.J. Jacobs, R.W.A. van der Heijden
 * @copyright 2015 Dual Inventive Technology Centre B.V.
 *
 * General purpose timer class including callback mechanism
 */
#ifndef INCLUDE_DI_TIMER_H_
#define INCLUDE_DI_TIMER_H_

#include <memory>
#include <thread>
#include <chrono>
#include <functional>
#include <atomic>
#include <mutex>

namespace Di {
/**
 * @class Timer
 *
 * Generic timer class
 */
class Timer {
 public:
	/**
	 * Constructor
	 */
	Timer();

	/**
	 * Destructor
	 */
	~Timer();

	/**
	 * Set duration of timer
	 * - Save timer duration
	 * - Calculate end time with now() + d
	 * @param d Duration
	 */
	void set(std::chrono::milliseconds d);

	/**
	 * Reset timer
	 * - Calculate new end time with now() previous set duration
	 */
	void reset(void);

	/**
	 * Set timer in "running" state
	 */
	void start(void);

	/**
	 * Set timer in "non-running" state
	 */
	void stop(void);

	/**
	 * Set callback for timeout
	 * @note This function may only be called before the timer is started or when the timer is stopped
	 * @param func Callback function
	 */
	void setCallback(std::function<void(Timer *)> func);

	/**
	 * Check if timer has elapsed
	 * @return false When timer is non-running or not expired
	 * @return true  When timer has elapsed
	 */
	bool isElapsed(void);

	/**
	 * function to immediately trigger the timeout
	 */
	void trigger(void);

 private:
	std::atomic_bool __stopped;

	std::mutex __endLock;	 ///< mutex to lock the __duration and __end access
	std::chrono::milliseconds __duration;
	std::chrono::steady_clock::time_point __end;

	std::function<void(Timer *)> __callback;
	std::shared_ptr<std::thread> __t;
	std::atomic_bool __hasReset;

	/**
	 * Callback thread
	 */
	void __callCallback(void);
};

}  // namespace Di


#endif  // INCLUDE_DI_TIMER_H_