/*
 * JBoss, Home of Professional Open Source
 * Copyright 2011, Red Hat, Inc. and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.mobicents.protocols.ss7.m3ua.impl.as;

import javolution.util.FastList;

import org.apache.log4j.Logger;
import org.mobicents.protocols.ss7.m3ua.impl.Asp;
import org.mobicents.protocols.ss7.m3ua.impl.AspState;
import org.mobicents.protocols.ss7.m3ua.impl.TransitionState;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.FSM;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.State;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.StateEventHandler;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.UnknownTransitionException;

/**
 * {@link AsStatePenTimeout#onEvent(State)} is called when the pending timer
 * T(r) expires.
 * 
 * @author amit bhayani
 *
 */
public class AsStatePenTimeout implements StateEventHandler {

    private AsImpl as;
    private FSM fsm;
    private static final Logger logger = Logger.getLogger(AsStatePenTimeout.class);

    boolean inactive = false;

    public AsStatePenTimeout(AsImpl as, FSM fsm) {
        this.as = as;
        this.fsm = fsm;
    }

	/**
	 * <p>
	 * An active ASP has transitioned to ASP-INACTIVE or ASP DOWN and it was the
	 * last remaining active ASP in the AS. A recovery timer T(r) SHOULD be
	 * started, and all incoming signalling messages SHOULD be queued by the
	 * SGP. If an ASP becomes ASP-ACTIVE before T(r) expires, the AS is moved to
	 * the AS-ACTIVE state, and all the queued messages will be sent to the ASP.
	 * </p>
	 * <p>
	 * If T(r) expires before an ASP becomes ASP-ACTIVE, and the SGP has no
	 * alternative, the SGP may stop queuing messages and discard all previously
	 * queued messages. The AS will move to the AS-INACTIVE state if at least
	 * one ASP is in ASP-INACTIVE; otherwise, it will move to AS-DOWN state.
	 * </p>
	 */
    public void onEvent(State state) {
    	
		//Clear the Pending Queue for this As
		this.as.clearPendingQueue();
		
        this.inactive = false;
        // check if there are any ASP's who are INACTIVE, transition to
        // INACTIVE else DOWN
        for (FastList.Node<Asp> n = this.as.getAspList().head(), end = this.as.getAspList().tail(); (n = n
                .getNext()) != end;) {
            Asp asp = n.getValue();
            if (asp.getState() == AspState.INACTIVE) {
                try {
                    this.fsm.signal(TransitionState.AS_INACTIVE);
                    inactive = true;
                    break;
                } catch (UnknownTransitionException e) {
                	logger.error(e.getMessage(), e);
                }

            }// if
        }// for

        if (!this.inactive) {
            // else transition to DOWN
            try {
                this.fsm.signal(TransitionState.AS_DOWN);
                inactive = true;
            } catch (UnknownTransitionException e) {
            	logger.error(e.getMessage(), e);
            }
        }
    }

}