package org.dancres.blitz.remote;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.InvalidObjectException;

import net.jini.id.Uuid;

import net.jini.core.transaction.server.TransactionParticipant;

import net.jini.core.constraint.RemoteMethodControl;
import net.jini.core.constraint.MethodConstraints;

import net.jini.security.proxytrust.ProxyTrustIterator;
import net.jini.security.proxytrust.SingletonProxyTrustIterator;

/**
   When the remote stub generated by the exporter implements
   RemoteMethodControl, Blitz exports this proxy for participant duties to
   support appropriate constraints etc.
 */
public final class ConstrainableTxnParticipantProxy extends
    TxnParticipantProxy implements RemoteMethodControl {

    private static TransactionParticipant constrainStub(TransactionParticipant aServer, MethodConstraints aConstraints) {
        RemoteMethodControl myServer = (RemoteMethodControl) aServer;

        myServer.setConstraints(aConstraints);
        return (TransactionParticipant) myServer;
    }

    private final MethodConstraints theConstraints;

    ConstrainableTxnParticipantProxy(TransactionParticipant aPart,
                                     Uuid aUuid) {
        super(aPart, aUuid);
        theConstraints = null;
    }

    private ConstrainableTxnParticipantProxy(TransactionParticipant aPart,
                                             Uuid aUuid,
                                             MethodConstraints aConstraints) {
        super(constrainStub(aPart, aConstraints), aUuid);
        theConstraints = aConstraints;
    }

    private ProxyTrustIterator getProxyTrustIterator() {
        return new SingletonProxyTrustIterator(theStub);
    }

    public RemoteMethodControl setConstraints(MethodConstraints aConstraints) {
        return new ConstrainableTxnParticipantProxy(theStub, theUuid,
                                                    aConstraints);
        
    }

    public MethodConstraints getConstraints() {
        return theConstraints;
    }

    private void readObject(ObjectInputStream anOIS)
        throws IOException, ClassNotFoundException {

        anOIS.defaultReadObject();

        if(! (theStub instanceof RemoteMethodControl) ) {
            throw new InvalidObjectException("space does not implement RemoteMethodControl");
        }
    }
}