import java.text.DecimalFormat;
import java.util.Scanner;

public class VendingApplication
{
    static Scanner input = new Scanner(System.in);
    static DecimalFormat currency = new DecimalFormat("0.00");
    static int qtyCoke = 10;
    static int qty7up = 10;
    static int qtyFanta = 2;
    static double totalCash = 0;
    static int numTransaction = 0;
    static int pin = 1234;


	public static void main(String[] args)
	{
		menu();
	}

	public static void menu()
	{
		System.out.println("Welcome to the BFEI vending Machine");
		System.out.println("-----------------------------------");
		System.out.println("Press 1 for Coke");
		System.out.println("Press 2 for 7up");
		System.out.println("Press 3 for Fanta");
		System.out.println("-----------------------------------");

		String choice = input.next();

		switch(choice)
		{
			case "1":
			{
				if(qtyCoke==0)
				{
					System.out.println("Item out of stock. Please choose another.");
					menu();
				}

			   String product = "Coke";
			   double price = 1.20;
			   payment(product, price);
			   break;
			}
			case "2":
			{
				if(qty7up==0)
				{
					System.out.println("Item out of stock. Please choose another.");
					menu();
				}

				String product = "7up";
				double price = 1.10;
				payment(product, price);
				break;
			}
			case "3":
			{
				if(qtyFanta==0)
				{
					System.out.println("Item out of stock. Please choose another.");
					menu();
				}

				String product = "Fanta";
				double price = 1;
				payment(product, price);
				break;
			}
			case "a":
			{
				System.out.println("Please enter pin number");
				int enteredPin = input.nextInt();

				if(enteredPin==pin)
				{
					System.out.println("Correc Pin. Loading Admin Mode");
	                admin();
				}
				else
				{
					System.out.println("Incorrect Pin. Try again");
				}
				break;
			}
			case "x":
			{
				System.out.println("System  closing down");
				System.exit(0);
				break;
			}
			default:
			{
				System.out.println("Invalid choice. Please choose again.");
				break;
			}
		}

		menu();

	}

	public static void payment(String productChoice, double transactionPrice)
	{
		System.out.println("Enter Payment. Balance is " + currency.format(transactionPrice));

		double moneyEntered = input.nextDouble(); //User enters payment

		while(moneyEntered<transactionPrice)
		{
			System.out.println("Enter payment. Balance remaining is " + currency.format((transactionPrice-moneyEntered)));
			moneyEntered = moneyEntered + input.nextDouble();//User tops up payment and overwrites existing amount
		}
		//Product has been purchased at this point
		if(moneyEntered>transactionPrice)
		{
			System.out.println("Changedue is " + currency.format((moneyEntered-transactionPrice)));
		}
		System.out.println("Trasaction Succesful. Please take your product");

		numTransaction++;
		totalCash = totalCash + transactionPrice; // Update total takings with value of the transaction

		if(productChoice.equals("Coke"))
		{
			qtyCoke--;
		}
		else if(productChoice.equals("Fanta"))
		{
			qtyFanta--;
		}
		{
			qty7up--;
		}

	}

	public static void admin()
	{
		System.out.println("Total Takings: €" + currency.format(totalCash));
		System.out.println("Number of Transactions: " + numTransaction);
		System.out.println("Average Value of a Transaction" + currency.format((totalCash/numTransaction)));
		System.out.println("Coke Stock Remaining" + qtyCoke);
		System.out.println("7up Stock Remaining" + qty7up);
		System.out.println("Fanta Stock Remaining" + qtyFanta);

		System.out.println("Press r to restock or any other key to exit");

		String choice = input.next();

	    if(choice.equals("r"))
	    {
	    	qtyCoke=10;
	    	qty7up=10;
	    	qtyFanta=2;
	    }

	}
}