#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;
// Funkcija vraca slucajan broj na intervalu od 0 do 1
double random() {
	return rand()/(1.0*RAND_MAX);
}
// Stanja
enum state {
	reading_card, // Citam kartu
	reading_pin, // Citam PIN
	choosing_transaction, // Izabiram transakciju
	performing_transaction, // Transakcija
	ejecting_card // Izbacujem karticu
};
// Dogadjaji
enum event {
	card_readable, // Kartica moze da se procita
	card_not_readable, // Kartica ne moze da se procita
	cancel, // Otkazivanje
	pin_read, // Ucitan PIN
	invalid_pin, // Neispravan PIN
	transaction_chosen, // Izabrana transakcija
	another_transaction, // Druga transakcija
	customer_finished // Korisnik zavrsava
};

// Dijagram stanja
class statechart {
	// Zastavica prelaska u zavrsno stanje
	bool _final;
	// Tekuce stanje
	state _current;
	public:
	// Konstruktor
	statechart(): _final(false) {}
	 // Postavljamo pocetno stanje
	void initial(const state s) {
		_current = s;
	}
	 // Tranzicija iz stanja u stanje na osnovu okinutog dogadjaja
	 void transition(const event e) {
	 // Proveravamo koji je dogadjaj okinut i na osnovu okinutog dogadjaja
	 // i stanja u kome se dijagram nalazi sprovodimo promenu stanja.
	 switch (e){
	case card_readable:
		if(_current==reading_card) {
			_current = reading_pin;
			cout << "READING_PIN" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
		case card_not_readable:
		if(_current==reading_card) {
			_current = ejecting_card;
			cout << "EJECTING_CARD" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
	 case cancel:
		if(_current==reading_pin) {
			_current = ejecting_card;
			cout << "EJECTING_CARD" << endl;
		}
		else if(_current==choosing_transaction) {
			_current = ejecting_card;
			cout << "EJECTING_CARD" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
	case pin_read:
		if(_current==reading_pin) {
			_current = choosing_transaction;
			cout << "CHOOSING_TRANSACTION" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
	 case invalid_pin:
		if(_current==reading_pin) {
			_current = reading_pin;
			cout << "READING_PIN" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
	 case transaction_chosen:
		if(_current==choosing_transaction) {
			_current = performing_transaction;
			cout << "PERFORMING_TRANSACTION" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
	case another_transaction:
		if(_current==performing_transaction) {
			_current = choosing_transaction;
			cout << "CHOOSING_TRANSACTION" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
	case customer_finished:
		if(_current==performing_transaction) {
			_current = ejecting_card;
			cout << "EJECTING_CARD" << endl;
		}
		else {
			cerr << "Error" << std::endl;
			exit(1);
		}
		break;
	default:
		break;
	}
 }
public:
	// Postavi u finalno stanje i vrati da li je u finalnom stanju
	bool get_final() { return _final; }
	void set_final(const bool f) { _final = f; }
	// Postavi i vrati tekuce stanje
	void set_current(const state s) { _current = s; }
	state get_current() const { return _current; }
};

int main() {
	// Verovatnoca
	double p;
	// Broj pogresno unetih pinova
	int ip = 1;
	// Objekat dijagrama stanja
	statechart sc;
	// Pocetno seme generatora slucajnih brojeva
	srand(time(NULL));
	// Postavljamo pocetno stanje
	sc.initial(reading_card);
	cout << "READING_CARD" << endl;
	 // Prolazimo kroz sva stanja dijagrama stanja dok ne dodjemo do finalnog
	while(!sc.get_final()) {
		if(sc.get_current()==reading_card) {
			p = random();
			if(p<=0.05) {
				sc.transition(card_not_readable);
			}
			else {
				sc.transition(card_readable);
			}
		}
		else if(sc.get_current()==reading_pin) {
			p = random();
			if(p<=0.05) {
				if(ip<3) {
					sc.transition(invalid_pin);
					++ip;
				}
				else {
					sc.set_final(true);
				}
			}
			else if(p<=0.30) {
				sc.transition(cancel);
			}
			else {
				sc.transition(pin_read);
			}
		}
		else if(sc.get_current()==choosing_transaction) {
			 p = random();
			if(p<=0.20) {
				sc.transition(cancel);
			}
			else {
				sc.transition(transaction_chosen);
			}
		}
		else if(sc.get_current()==performing_transaction) {
			p = random();
			if(p<=0.40) {
				 sc.transition(another_transaction);
			}
			else {
				 sc.transition(customer_finished);
			}
		}
		else if(sc.get_current()==ejecting_card) {
			 sc.set_final(true);
		}
	}
	return 0;
}