/*
 * © Copyright 2014 – Urheberrechtshinweis
 * Alle Rechte vorbehalten / All Rights Reserved
 *
 * Programmcode ist urheberrechtlich geschuetzt.
 * Das Urheberrecht liegt, soweit nicht ausdruecklich anders gekennzeichnet, bei Frank Ebner.
 * Keine Verwendung ohne explizite Genehmigung.
 * (vgl. § 106 ff UrhG / § 97 UrhG)
 */

#ifndef HISTORYTS_H
#define HISTORYTS_H

#include <vector>
#include "Timestamp.h"
#include <algorithm>

/**
 * keep the history of values for a given amount of time
 */
template <typename T> class HistoryTS {

private:

	/** timestamp -> value combination */
	struct Entry {
		Timestamp ts;
		T value;
		Entry(const Timestamp ts, const T& value) : ts(ts), value(value) {;}
	};

	/** the time-window to keep */
	Timestamp window;

	/** the value history for the window-size */
	std::vector<Entry> history;

public:


	/** ctor with the time-window to keep */
	HistoryTS(const Timestamp window) : window(window) {

	}

	/** add a new entry */
	void add(const Timestamp ts, const T& data) {

		// append to history
		history.push_back(Entry(ts, data));

		// remove too-old history entries
		const Timestamp oldest = ts - window;
		while(history.front().ts < oldest) {

			// remove from history
			history.erase(history.begin());

		}

	}

	/** get the most recent entry */
	T getMostRecent() const {
		return history.back().value;
	}

	/** get the oldest entry available */
	T getOldest() const {
		return history.front().value;
	}



};


#endif // HISTORYTS_H