package credit;

import java.rmi.*;
import java.rmi.server.*;
import java.io.Serializable;

/** This class is the remote object that will referenced by the skeleton
    on the server side and the stub on the client side. */
    
public class CreditCardImpl
    extends UnicastRemoteObject
    implements CreditCard, Serializable
 {
    private float currentBalance = 0;
    private float creditLine = 5000f;
    private int signature = 0;         // Like a p.i.n. number
    private String accountName;        // Name of owner

    /** Class constructor generatesan initial pin.*/
    public CreditCardImpl(String customer)
    throws RemoteException, DuplicateAccountException {
        accountName = customer;
        signature = (int)(Math.random() * 10000);
    }

    /** Returns credit line. */
    public float getCreditLine() throws RemoteException {
        return creditLine;
    }

    /** Pays off some debt. */
    public void payTowardsBalance(float money)
    throws RemoteException, InvalidMoneyException {
        if (money <= 0) {
            throw new InvalidMoneyException ();
        } else {
            currentBalance -= money;
        }
    }

    /** Changes signature. */
    public void setSignature(int pin) throws RemoteException {
        signature = pin;
    }
 
    /** Makes a purchase. Makes sure enough credit is available,
        then increments balance and decrements available credit. */
    public void makePurchase(float amount, int signature)
    throws RemoteException, InvalidSignatureException,
    CreditLineExceededException {
        if (signature != this.signature) {
            throw new InvalidSignatureException();
        }
        if (currentBalance+amount > creditLine) {
            throw new CreditLineExceededException();
        } else {
            currentBalance += amount;
            creditLine -= amount;
        }
    }    
}