Bank.java

import java.util.*;


public class Bank
{
    private String name;

    private ArrayList<User> users;

    private ArrayList<Account> accounts;

    public Bank(String name)
    {
	this.name=name;
	this.users=new ArrayList<User>();
	this.accounts=new ArrayList<Account>();
    }

    public String getNewUserUUID()
    {
        String uuid;
	Random rng=new Random();
	int len=6;
	boolean nonUnique;

	do{
	    uuid="";

	    for(int c=0;c<len;c++)
		{
		    uuid+=((Integer)rng.nextInt(10)).toString();
		}
	    nonUnique=false;

	    for(User u:this.users)
		{
		    if(uuid.compareTo(u.getUUID())==0)
			{
			    nonUnique=true;
			    break;
			}
		}
	}while(nonUnique);


	return uuid;

    }

    public String getNewAccountUUID()
    {
         String uuid;
	Random rng=new Random();
	int len=10;
	boolean nonUnique;

	do{
	    uuid="";

	    for(int c=0;c<len;c++)
		{
		    uuid+=((Integer)rng.nextInt(10)).toString();
		}
	    nonUnique=false;

	    for(Account a:this.accounts)
		{
		    if(uuid.compareTo(a.getUUID())==0)
			{
			    nonUnique=true;
			    break;
			}
		}
	}while(nonUnique);


	return uuid;

    }

    
		
    public void addAccount(Account anAcct)
    {
	this.accounts.add(anAcct);
    }

   

    public User addUser(String firstName,String lastName,String pin)
    {
	User newUser =new User(firstName,lastName,pin,this);

	this.users.add(newUser);

	Account newAccount=new Account("Savings", newUser,this);
	newUser.addAccount(newAccount);
	this.addAccount(newAccount);

	return newUser;

    }

    public User userLogin(String userID,String pin)
    {
	for(User u:this.users)
	    {
		if(u.getUUID().compareTo(userID)==0 && u.validatePin(pin))
		    {
			return u;
		    }
	    }
	return null;
    }

    public String getName()
    {
	return this.name;
    }

}