StatisticsDisplay.h

#ifndef STATISTICS_DISPLAY_H
#define STATISTICS_DISPLAY_H

#include "Subject.h"
#include "Observer.h"
#include "DisplayElement.h"
#include "WeatherData.h"
#include <iostream>

class StatisticsDisplay : public Observer, public DisplayElement {
	public:
		StatisticsDisplay() = default;
		StatisticsDisplay(Subject *wd) : weatherData(wd)
	                                { weatherData->registerObserver(this); }
		void update(double t, double h, double p) override;
		void display() const override;
	private:
		double minTemp = 200.0f;
		double maxTemp = 0.0f;
		double tempSum = 0.0f;
		int numberOfReadings = 0;
		Subject *weatherData = nullptr;
};

inline
void
StatisticsDisplay::update(double t, [[maybe_unused]] double h, [[maybe_unused]] double p) {
	tempSum += t;
	++numberOfReadings;
	if (t < minTemp)
		minTemp = t;
	if (t > maxTemp)
		maxTemp = t;
	display();
}

inline
void
StatisticsDisplay::display() const {
	std::cout << "Avg/Max/Min Temperature = " <<
		tempSum / numberOfReadings << "/" << maxTemp << "/" << minTemp << '\n';
}

#endif /* ifndef STATISTICS_DISPLAY_H */