/*
 * 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.sg;

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.fsm.FSM;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.State;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.TransitionHandler;
import org.mobicents.protocols.ss7.m3ua.message.MessageClass;
import org.mobicents.protocols.ss7.m3ua.message.MessageType;
import org.mobicents.protocols.ss7.m3ua.message.mgmt.Notify;
import org.mobicents.protocols.ss7.m3ua.parameter.Status;
import org.mobicents.protocols.ss7.m3ua.parameter.TrafficModeType;

/**
 * 
 * @author amit bhayani
 *
 */
public class RemAsTransActToPendRemAspDwn implements TransitionHandler {

    private static final Logger logger = Logger.getLogger(RemAsTransActToPendRemAspDwn.class);

    private RemAsImpl as = null;
    private FSM fsm;

    private int lbCount = 0;

    public RemAsTransActToPendRemAspDwn(RemAsImpl as, FSM fsm) {
        this.as = as;
        this.fsm = fsm;
    }

    public boolean process(State state) {
        try {
            RemAspImpl remAsp = (RemAspImpl) this.fsm.getAttribute(RemAsImpl.ATTRIBUTE_ASP);

            if (this.as.getTrafficModeType().getMode() == TrafficModeType.Broadcast) {
                // We don't support this
                return false;

            }

            if (this.as.getTrafficModeType().getMode() == TrafficModeType.Loadshare) {
                this.lbCount = 0;

                for (FastList.Node<Asp> n = this.as.getAspList().head(), end = this.as.getAspList()
                        .tail(); (n = n.getNext()) != end;) {
                    RemAspImpl remAspImpl = (RemAspImpl) n.getValue();
                    if (remAspImpl.getState() == AspState.ACTIVE) {
                        this.lbCount++;
                    }
                }// for

                // TODO : yet not sure. May be the communication died with this
                // ASP who is causing this Transition; so the state will still
                // be ACTIVE for it
                if (remAsp.getState() == AspState.ACTIVE) {
                    this.lbCount--;
                }

                if (this.lbCount >= this.as.getMinAspActiveForLb()) {
                    // we still have more ASP's ACTIVE for lb. Don't change
                    // state
                    return false;
                }

                if (this.lbCount > 0) {
                    // In any case if we have at least one ASP that can take
                    // care of traffic, don't change state

                    // But we are below threshold. Send "Ins. ASPs" to INACTIVE
                    // ASP's but not to ASP that caused this transition as it is
                    // already DOWN
                    for (FastList.Node<Asp> n = this.as.getAspList().head(), end = this.as
                            .getAspList().tail(); (n = n.getNext()) != end;) {
                        RemAspImpl remAspTemp = (RemAspImpl) n.getValue();

                        // TODO : needed? The state should be changed before
                        // signalling AS transition
                        if (remAspTemp.getName().compareTo(remAsp.getName()) == 0) {
                            continue;
                        }
                        if (remAspTemp.getState() == AspState.INACTIVE) {
                            Notify notify = this.createNotify(remAsp, Status.STATUS_Other,
                                    Status.INFO_Insufficient_ASP_Resources_Active);
                            remAspTemp.getAspFactory().write(notify);
                        }
                    }

                    return false;
                }

            }//If Loadshare

            // We have reached here means AS is transitioning to be PENDING.
            // Send new AS STATUS to all INACTIVE APS's

            for (FastList.Node<Asp> n = this.as.getAspList().head(), end = this.as.getAspList()
                    .tail(); (n = n.getNext()) != end;) {
                remAsp = (RemAspImpl) n.getValue();
                if (remAsp.getState() == AspState.INACTIVE) {
                    Notify notify = this.createNotify(remAsp, Status.STATUS_AS_State_Change, Status.INFO_AS_PENDING);
                    remAsp.getAspFactory().write(notify);
                }
            }

        } catch (Exception e) {
            logger.error(String.format("Error while translating Rem AS to PENDING. %s", this.fsm.toString()), e);
        }

        return true;
    }

    private Notify createNotify(RemAspImpl remAsp, int type, int info) {
        Notify msg = (Notify) this.as.getM3UAProvider().getMessageFactory().createMessage(MessageClass.MANAGEMENT,
                MessageType.NOTIFY);

        Status status = this.as.getM3UAProvider().getParameterFactory().createStatus(type, info);
        msg.setStatus(status);

        if (remAsp.getASPIdentifier() != null) {
            msg.setASPIdentifier(remAsp.getASPIdentifier());
        }

        msg.setRoutingContext(this.as.getRoutingContext());

        return msg;
    }

}