#include <iomanip>
#include <iostream>
#include <string>
using namespace std;
const char poundSign(156);
const char dollerSign(36);
const char euroSign(128);
const char hashtag(35);

double fullPriceGoods, discountedGoods, deliverycharge;
double topay;
double discountrate;

double const discountrate1 = 0.8;
double const discountrate2 = 0.7;
double const discountrate3 = 0.5;

int sumofcode;

bool validCode;

void calculateTotalDiscountedGoods();
void toPay();
void checkValidVoucherCode();

int main()
{
	cout.setf(ios::fixed);
	cout << setprecision(2);

	cout << "Order value without discout: "<< poundSign;
	cin >> fullPriceGoods;

	if (fullPriceGoods > 0)
	{
		checkValidVoucherCode();
		if (validCode == true)
		{
			cout << "Valid voucher - free delivery. \n";
			calculateTotalDiscountedGoods();
			deliverycharge = 0.00;
			cout << "Order value with discount: " << poundSign << discountedGoods << "\n";
			cout << "Delivery charge: " << poundSign << deliverycharge << "\n";
			toPay();
			cout << "To pay: " << poundSign << topay << "\n";
		}
		else
		{
			cout << "Invalid voucher. \n";
			calculateTotalDiscountedGoods();
			deliverycharge = 6.50;
			cout << "Order value with discount: " << poundSign << discountedGoods << "\n";
			cout << "Delivery charge: " << poundSign << deliverycharge << "\n";
			toPay();
			cout << "To pay: " << poundSign << topay << "\n";
		}
	}
	else
	{
		cout << "ERROR: The order value should be a positive number! \n";
	}
	system("pause");
	return 0;
}

void calculateTotalDiscountedGoods()
{
	if (fullPriceGoods <= 30.00)
	{
		discountrate = discountrate1;
	}
	else if (fullPriceGoods > 30.00 && fullPriceGoods <= 60.00)
	{
		discountrate = discountrate2;
	}
	else
	{
		discountrate = discountrate3;
	}
	discountedGoods = fullPriceGoods * discountrate;
}

void toPay()
{
	if (validCode == true)
	{
		topay = discountedGoods;
	}
	else
	{
		topay = discountedGoods + deliverycharge;
	}
}

void checkValidVoucherCode()
{
	int voucherCode, firstNumber, secondNumber, thirdNumber, fourthNumber, total;

	total = 12;
	cout << "Voucher code: " << hashtag;
	cin >> voucherCode;

	if (voucherCode >= 1000 && voucherCode <= 9999)
	{
		firstNumber = (voucherCode % 10);
		secondNumber = ((voucherCode /10) % 10);
		thirdNumber = ((voucherCode / 100) % 10);
		fourthNumber = ((voucherCode / 1000) % 10);
		sumofcode = firstNumber + secondNumber + thirdNumber + fourthNumber;

		if (sumofcode = total)
		{
			validCode == true;
		}
		else
		{
			validCode == false;
		}
	}
	else
	{
		validCode == false;
	}
}