/*
 * Copyright (C) 2003-2011 eXo Platform SAS.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.etk.component.base.transaction.impl.jboss;

import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.ObjectName;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.transaction.RollbackException;
import javax.transaction.SystemException;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import javax.transaction.UserTransaction;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;

import org.etk.component.base.transaction.ExoResource;
import org.etk.component.base.transaction.TransactionService;

/**
 * Created by The eXo Platform SAS
 * Author : eXoPlatform
 *          thanhvucong.78@google.com
 * Aug 6, 2011  
 */
public class JBossTransactionService implements TransactionService {

   /** . */
  private volatile TransactionManager tm;

  public TransactionManager getTransactionManager() {
    if (tm == null) {
      try {
        tm = (TransactionManager) new InitialContext().lookup("java:/TransactionManager");
      } catch (NamingException e) {
        throw new IllegalStateException(e);
      }
    }
    return tm;
  }

  public UserTransaction getUserTransaction() {
    try {
      return (UserTransaction) new InitialContext().lookup("java:/TransactionManager");
    } catch (NamingException e) {
      throw new IllegalStateException(e);
    }
  }

  public int getDefaultTimeout() {
    try {
      MBeanServer server = (MBeanServer) MBeanServerFactory.findMBeanServer(null).iterator().next();
      return (Integer) server.getAttribute(ObjectName.getInstance("jboss:service=TransactionManager"),
                                           "TransactionTimeout");
    } catch (Exception e) {
      throw new IllegalStateException(e);
    }
  }

  public void setTransactionTimeout(int seconds) throws SystemException {
    TransactionManager tm = getTransactionManager();
    tm.setTransactionTimeout(seconds);
  }

  public void enlistResource(ExoResource exores) throws RollbackException, SystemException {
    TransactionManager tm = getTransactionManager();
    Transaction tx = tm.getTransaction();
    tx.enlistResource(exores.getXAResource());
  }

  public void delistResource(ExoResource exores) throws RollbackException, SystemException {
    TransactionManager tm = getTransactionManager();
    Transaction tx = tm.getTransaction();
    tx.delistResource(exores.getXAResource(), XAResource.TMNOFLAGS);
  }

  public Xid createXid() {
    // Convenient method used by JCR tests to manufacture an xid
    // it should be removed
    //
    throw new UnsupportedOperationException("Only used by JCR impl in tests");
  }
}