/*
 * @(#)CorbaContactInfoListIteratorImpl.java	1.29 04/06/21
 * 
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.corba.se.impl.transport;

import java.util.Iterator;
import java.util.List;

import org.omg.CORBA.COMM_FAILURE;
import org.omg.CORBA.CompletionStatus;
import org.omg.CORBA.INTERNAL;
import org.omg.CORBA.SystemException;

import com.sun.corba.se.pept.transport.ContactInfo ;
import com.sun.corba.se.pept.transport.ContactInfoList ;

import com.sun.corba.se.spi.ior.IOR ;
import com.sun.corba.se.spi.logging.CORBALogDomains;
import com.sun.corba.se.spi.orb.ORB ;
import com.sun.corba.se.spi.transport.CorbaContactInfo;
import com.sun.corba.se.spi.transport.CorbaContactInfoList;
import com.sun.corba.se.spi.transport.CorbaContactInfoListIterator;
import com.sun.corba.se.spi.transport.IIOPPrimaryToContactInfo;

import com.sun.corba.se.impl.logging.ORBUtilSystemException;
import com.sun.corba.se.impl.protocol.CorbaInvocationInfo;

// REVISIT: create a unit test for this class.

public class CorbaContactInfoListIteratorImpl
    implements
	CorbaContactInfoListIterator
{
    protected ORB orb;
    protected CorbaContactInfoList contactInfoList;
    protected CorbaContactInfo successContactInfo;
    protected CorbaContactInfo failureContactInfo;
    protected RuntimeException failureException;

    // ITERATOR state
    protected Iterator effectiveTargetIORIterator;
    protected CorbaContactInfo previousContactInfo;
    protected boolean isAddrDispositionRetry;
    protected IIOPPrimaryToContactInfo primaryToContactInfo;
    protected ContactInfo primaryContactInfo;
    protected List listOfContactInfos;
    // End ITERATOR state

    public CorbaContactInfoListIteratorImpl(
        ORB orb,
	CorbaContactInfoList corbaContactInfoList,
	ContactInfo primaryContactInfo,
	List listOfContactInfos)
    {
	this.orb = orb;
	this.contactInfoList = corbaContactInfoList;
	this.primaryContactInfo = primaryContactInfo;
	if (listOfContactInfos != null) {
	    // listOfContactInfos is null when used by the legacy
	    // socket factory.  In that case this iterator is NOT used.
	    this.effectiveTargetIORIterator = listOfContactInfos.iterator();
	}
	// List is immutable so no need to synchronize access.
	this.listOfContactInfos = listOfContactInfos;

	this.previousContactInfo = null;
	this.isAddrDispositionRetry = false;

	this.successContactInfo = null;
	this.failureContactInfo = null;
	this.failureException = null;

	primaryToContactInfo = orb.getORBData().getIIOPPrimaryToContactInfo();
    }

    ////////////////////////////////////////////////////
    //
    // java.util.Iterator
    //

    public boolean hasNext()
    {
	// REVISIT: Implement as internal closure iterator which would
	// wraps sticky or default.  Then hasNext and next just call
	// the closure.

	if (isAddrDispositionRetry) {
	    return true;
	}

	boolean result;

	if (primaryToContactInfo != null) {
	    result = primaryToContactInfo.hasNext(primaryContactInfo,
						  previousContactInfo,
						  listOfContactInfos);
	} else {
	    result = effectiveTargetIORIterator.hasNext();
	}

	return result;
    }

    public Object next()
    {
	if (isAddrDispositionRetry) {
	    isAddrDispositionRetry = false;
	    return previousContactInfo;
	}

	// We hold onto the last in case we get an addressing
	// disposition retry.  Then we use it again.

	// We also hold onto it for the sticky manager.

	if (primaryToContactInfo != null) {
	    previousContactInfo = (CorbaContactInfo)
		primaryToContactInfo.next(primaryContactInfo,
					  previousContactInfo,
					  listOfContactInfos);
	} else {
	    previousContactInfo = (CorbaContactInfo)
		effectiveTargetIORIterator.next();
	}

	return previousContactInfo;
    }

    public void remove()
    {
	throw new UnsupportedOperationException();
    }

    ////////////////////////////////////////////////////
    //
    // com.sun.corba.se.pept.transport.ContactInfoListIterator
    //

    public ContactInfoList getContactInfoList()
    {
	return contactInfoList;
    }

    public void reportSuccess(ContactInfo contactInfo)
    {
	this.successContactInfo = (CorbaContactInfo)contactInfo;
    }

    public boolean reportException(ContactInfo contactInfo, 
				   RuntimeException ex)
    {
	this.failureContactInfo = (CorbaContactInfo)contactInfo;
	this.failureException = ex;
	if (ex instanceof COMM_FAILURE) {
	    SystemException se = (SystemException) ex;
	    if (se.completed == CompletionStatus.COMPLETED_NO) {
		if (hasNext()) {
		    return true;
		}
		if (contactInfoList.getEffectiveTargetIOR() !=
		    contactInfoList.getTargetIOR()) 
                {
		    // retry from root ior
		    updateEffectiveTargetIOR(contactInfoList.getTargetIOR());
		    return true;
		}
	    }
	}
	return false;
    }

    public RuntimeException getFailureException()
    {
	if (failureException == null) {
	    return
		ORBUtilSystemException.get( orb,
					    CORBALogDomains.RPC_TRANSPORT )
		    .invalidContactInfoListIteratorFailureException();
	} else {
	    return failureException;
	}
    }

    ////////////////////////////////////////////////////
    //
    // spi.CorbaContactInfoListIterator
    //

    public void reportAddrDispositionRetry(CorbaContactInfo contactInfo, 
					   short disposition)
    {
	previousContactInfo.setAddressingDisposition(disposition);
	isAddrDispositionRetry = true;
    }

    public void reportRedirect(CorbaContactInfo contactInfo,
			       IOR forwardedIOR)
    {
	updateEffectiveTargetIOR(forwardedIOR);
    }

    ////////////////////////////////////////////////////
    //
    // Implementation.
    //

    // 
    // REVISIT:
    // 
    // The normal operation for a standard iterator is to throw
    // ConcurrentModificationException whenever the underlying collection
    // changes.  This is implemented by keeping a modification counter (the
    // timestamp may fail because the granularity is too coarse).
    // Essentially what you need to do is whenever the iterator fails this
    // way, go back to ContactInfoList and get a new iterator.
    //
    // Need to update CorbaClientRequestDispatchImpl to catch and use 
    // that exception.
    //

    public void updateEffectiveTargetIOR(IOR newIOR)
    {
	contactInfoList.setEffectiveTargetIOR(newIOR);
	// If we report the exception in _request (i.e., beginRequest
	// we cannot throw RemarshalException to the stub because _request
	// does not declare that exception.
	// To keep the two-level dispatching (first level chooses ContactInfo,
	// second level is specific to that ContactInfo/EPT) we need to
	// ensure that the request dispatchers get their iterator from the 
	// InvocationStack (i.e., ThreadLocal). That way if the list iterator
	// needs a complete update it happens right here.
	((CorbaInvocationInfo)orb.getInvocationInfo())
	    .setContactInfoListIterator(contactInfoList.iterator());
    }
}

// End of file.
