/*
 * NOTE: This copyright does *not* cover user programs that use HQ program
 * services by normal system calls through the application program interfaces
 * provided as part of the Hyperic Plug-in Development Kit or the Hyperic Client
 * Development Kit - this is merely considered normal use of the program, and
 * does *not* fall under the heading of "derived work".
 * 
 * Copyright (C) [2004-2008], Hyperic, Inc. This file is part of HQ.
 * 
 * HQ is free software; you can redistribute it and/or modify it under the terms
 * version 2 of the GNU General Public License as published by the Free Software
 * Foundation. 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 General
 * Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA 02111-1307 USA.
 */

package org.hyperic.hq.appdef.server.session;

import java.util.List;

import javax.annotation.PostConstruct;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hyperic.hq.appdef.shared.AgentManager;
import org.hyperic.hq.appdef.shared.AppdefEntityID;
import org.hyperic.hq.authz.server.session.AuthzSubject;
import org.hyperic.hq.authz.shared.AuthzSubjectManager;
import org.hyperic.hq.zevents.ZeventEnqueuer;
import org.hyperic.hq.zevents.ZeventListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

/**
 * The Zevent Listener that upgrades agents.
 */
@Component
public class TransferAgentPluginZeventListener implements ZeventListener<TransferAgentPluginZevent> {

    private final Log _log = LogFactory.getLog(TransferAgentPluginZeventListener.class);

    private AgentManager agentManager;
    private AuthzSubjectManager authzSubjectManager;
    private ZeventEnqueuer zEventManager;

    @Autowired
    public TransferAgentPluginZeventListener(AgentManager agentManager, AuthzSubjectManager authzSubjectManager, ZeventEnqueuer zEventManager) {
        this.agentManager = agentManager;
        this.authzSubjectManager = authzSubjectManager;
        this.zEventManager = zEventManager;
    }
    
    @PostConstruct
    public void subscribe() {
        zEventManager.addBufferedListener(TransferAgentPluginZevent.class, this);
    }

    /**
     * @see org.hyperic.hq.zevents.ZeventListener#processEvents(java.util.List)
     */
    public void processEvents(List<TransferAgentPluginZevent> events) {
        AuthzSubject overlord = authzSubjectManager.getOverlordPojo();

        for (TransferAgentPluginZevent zevent : events) {
            final AppdefEntityID aid = zevent.getAgent();

            try {
                agentManager.transferAgentPlugin(overlord, zevent.getAgent(), zevent.getPlugin());
                agentManager.restartAgent(overlord, aid);
            } catch (Exception e) {
                _log.warn("Failed to transfer plugin " + zevent.getPlugin() + " to agent " + zevent.getAgent().getID(),
                    e);
            }
        }

    }

    public String toString() {
        return "AgentPluginTransfer";
    }

}