/**
 * Copyright (C) 2000-2010 Atomikos <info@atomikos.com>
 *
 * This code ("Atomikos TransactionsEssentials"), by itself,
 * is being distributed under the
 * Apache License, Version 2.0 ("License"), a copy of which may be found at
 * http://www.atomikos.com/licenses/apache-license-2.0.txt .
 * You may not use this file except in compliance with the License.
 *
 * While the License grants certain patent license rights,
 * those patent license rights only extend to the use of
 * Atomikos TransactionsEssentials by itself.
 *
 * This code (Atomikos TransactionsEssentials) contains certain interfaces
 * in package (namespace) com.atomikos.icatch
 * (including com.atomikos.icatch.Participant) which, if implemented, may
 * infringe one or more patents held by Atomikos.
 * It should be appreciated that you may NOT implement such interfaces;
 * licensing to implement these interfaces must be obtained separately from Atomikos.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 */

package com.atomikos.icatch.imp;

import java.util.Dictionary;

import com.atomikos.icatch.HeurCommitException;
import com.atomikos.icatch.HeurHazardException;
import com.atomikos.icatch.HeurMixedException;
import com.atomikos.icatch.HeurRollbackException;
import com.atomikos.icatch.HeuristicMessage;
import com.atomikos.icatch.Participant;
import com.atomikos.icatch.RollbackException;
import com.atomikos.icatch.SysException;
import com.atomikos.icatch.TransactionService;
import com.atomikos.icatch.system.Configuration;

/**
 * 
 * 
 * 
 * A participant for registering a subtx coordinator as a subordinate in 2PC of
 * the parent transaction coordinator.
 */

public class SubTransactionCoordinatorParticipant implements Participant
{
    private static final long serialVersionUID = -321213151844934630L;

    private transient Participant subordinateCoordinator;
    // the participant role of the subtx coordinator
    // NOT serializable -> recover by ID

    private String subordinateId;
    // the id to recover the participant of the subordinate

    private HeuristicMessage[] msgs;
    // buffer messages in case recovery fails

    private boolean prepareCalled;

    // if true: heuristics on failure of rollback

    public SubTransactionCoordinatorParticipant (
            CoordinatorImp subordinateCoordinator )
    {
        this.subordinateCoordinator = subordinateCoordinator;
        this.subordinateId = subordinateCoordinator.getCoordinatorId ();
        this.msgs = subordinateCoordinator.getHeuristicMessages ();
        this.prepareCalled = false;
    }

    /**
     * @see com.atomikos.icatch.Participant#recover()
     */
    public boolean recover () throws SysException
    {
        TransactionService ts = Configuration.getTransactionService ();
        subordinateCoordinator = ts.getParticipant ( subordinateId );
        return subordinateCoordinator != null;
    }

    /**
     * @see com.atomikos.icatch.Participant#getURI()
     */
    public String getURI ()
    {
        return subordinateId;
    }

    /**
     * @see com.atomikos.icatch.Participant#setCascadeList(java.util.Dictionary)
     */
    public void setCascadeList ( Dictionary allParticipants )
            throws SysException
    {
        // delegate to subordinate, in order to propagate to remote
        // work (even though the subordinate itself is local, its
        // registered participants may be remote!)
        subordinateCoordinator.setCascadeList ( allParticipants );

    }

    /**
     * @see com.atomikos.icatch.Participant#setGlobalSiblingCount(int)
     */
    public void setGlobalSiblingCount ( int count )
    {
        // delegate to subordinate, in order to propagate
        // to remote work
        subordinateCoordinator.setGlobalSiblingCount ( count );

    }

    /**
     * @see com.atomikos.icatch.Participant#prepare()
     */
    public int prepare () throws RollbackException, HeurHazardException,
            HeurMixedException, SysException
    {
        prepareCalled = true;
        return subordinateCoordinator.prepare ();
    }

    /**
     * @see com.atomikos.icatch.Participant#commit(boolean)
     */
    public HeuristicMessage[] commit ( boolean onePhase )
            throws HeurRollbackException, HeurHazardException,
            HeurMixedException, RollbackException, SysException
    {
        HeuristicMessage[] ret = getHeuristicMessages ();
        if ( subordinateCoordinator != null )
            subordinateCoordinator.commit ( onePhase );
        else if ( prepareCalled ) {
            throw new HeurHazardException ( ret );
        } else {
            // prepare NOT called -> subordinate timed out
            // and must have rolled back
            throw new RollbackException ();
        }
        return ret;
    }

    /**
     * @see com.atomikos.icatch.Participant#rollback()
     */
    public HeuristicMessage[] rollback () throws HeurCommitException,
            HeurMixedException, HeurHazardException, SysException
    {
        HeuristicMessage[] ret = getHeuristicMessages ();
        if ( subordinateCoordinator != null ) {
            subordinateCoordinator.rollback ();
        } else if ( prepareCalled ) {
            // heuristic: coordinator not recovered?!
            throw new HeurHazardException ( ret );
        }
        // if prepare not called then the subordinate will
        // not be committed, so rollback is correct then
        return ret;
    }

    /**
     * @see com.atomikos.icatch.Participant#forget()
     */
    public void forget ()
    {
        if ( subordinateCoordinator != null )
            subordinateCoordinator.forget ();

    }

    /**
     * @see com.atomikos.icatch.Participant#getHeuristicMessages()
     */
    public HeuristicMessage[] getHeuristicMessages ()
    {
        if ( subordinateCoordinator != null )
            msgs = subordinateCoordinator.getHeuristicMessages ();
        // subordinate is null if recovery failed
        return msgs;
    }

}
