import java.util.Scanner;
/**
 * This program is used to allow choice confirmation in a robust way.
 * All the methods in this class are static.
 * 
 * @author Kvass
 * @version 1.0
 */
public final class Confirmer
{
    /**
     * Prints out a menu of option choices and requires the user to select
     * a valid option choice.
     * @param message The prompt to display above the menu
     * @param args The menu choices
     * @return The option number from the menu
     */
    public static int menu(String message, String... args)
    {
        Scanner input = new Scanner(System.in);
        int choice = -1;
        boolean exit = false;
        do
        {
            try
            {
                System.out.println(message);
                int counter = 1;
                for (String s:args)
                {
                    System.out.println(counter+") "+s);
                    counter++;
                }
                System.out.print("Enter selection number: ");
                String temp = input.nextLine();
                choice = Integer.parseInt(temp);
                if (choice>0 && choice<counter)
                    exit = true;
                else
                    System.out.println("That number was not an option.");
            }
            catch (Exception e)
            {
                System.out.println("Error: Invalid input.");
            }
        }
        while (!exit);
        return choice;
    }
    
    /**
     * Displays a message and requires the user to answer yes or no.
     * @param message The prompt to display above the menu
     * @return true if the answer is yes, false if the answer is no.
     */
    public static boolean binaryQ(String message)
    {
        Scanner input = new Scanner(System.in);
        boolean choice = false;
        boolean exit = false;
        do
        {
            try
            {
                System.out.print(message);
                String temp = input.nextLine();
                if (temp.charAt(0) == 'y' || temp.charAt(0) == 'Y')
                {
                    choice = true;
                    exit = true;
                }
                else if (temp.charAt(0) == 'n' || temp.charAt(0) == 'N')
                {
                    choice = false;
                    exit = true;
                }
                else
                    System.out.println("It's a yes or no question.");
            }
            catch (Exception e)
            {
                System.out.println("Error: Invalid input.");
            }
        }
        while (!exit);
        return choice;
    }
    
    /**
     * Default constructor: private so this object cannot be constructed
     */
    private Confirmer(){}
}