import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;


public class Lab08
{
    public static void main(String[] args)
    {
        ArrayList<Person> roster = new ArrayList<Person>();
        Scanner in = new Scanner(System.in);
        int choice = 0;
        while (choice != 7)
        {
            System.out.println("\n1.  Add a person to the roster");
            System.out.println("2.  Remove a person from the roster");
            System.out.println("3.  Clear the roster");
            System.out.println("4.  Print the roster");
            System.out.println("5.  Save the roster");
            System.out.println("6.  Load a roster");
            System.out.println("7.  Quit");
            do
            {
                System.out.print("\nEnter your choice: ");
                choice = in.nextInt();
                if (choice < 1 || choice > 7)
                {
                    System.out.println("Invalid choice");
                }
            }
            while (choice < 1 || choice > 7);
            in.nextLine();
            
            switch (choice)
            {
            case 1:
                System.out.println("Creating a new user...\n");
                System.out.print("Enter the first name: ");
                String firstName = in.nextLine();
                System.out.print("Enter the last name: ");
                String lastName = in.nextLine();
                roster.add(new Person(firstName, lastName));
                break;
            case 2:
                System.out.print("Enter an index to remove: ");
                int index = in.nextInt();
                if (index < 0 || index >= roster.size())
                {
                    System.out.println("Invalid index.");
                }
                else
                {
                    roster.remove(index);
                }
                break;
            case 3:
                roster.clear();
                System.out.println("Roster cleared.");
                break;
            case 4:
                for (int i = 0; i < roster.size(); i++)
                {
                    System.out.println(i + ".  " + roster.get(i));
                }
                break;
            case 5:
                System.out.print("Enter a file to save to: ");
                String fileName = in.nextLine();
                PrintWriter pw = null;
                for (Person person : roster)
                {
                    person.writeTo(pw);
                }
                break;
            case 6:
                System.out.print("Enter a roster to load: ");
                String fileName = in.nextLine();
                Scanner s = null;
                Person p = Person.createPerson(s);
                int i;
                for (i = 0; p != null; i++)
                {
                    roster.add(p);
                    p = Person.createPerson(s);
                }
                System.out.println(i + " entries loaded.");
                break;
            case 7:
                System.out.println("Goodbye!");
            }
        }
    }
}