/**
 * Copyright (c) 2009--2014 Red Hat, Inc.
 *
 * This software is licensed to you under the GNU General Public License,
 * version 2 (GPLv2). There is NO WARRANTY for this software, express or
 * implied, including the implied warranties of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2
 * along with this software; if not, see
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * Red Hat trademarks are not licensed under GPLv2. No permission is
 * granted to use or replicate Red Hat trademarks that are incorporated
 * in this software or its documentation.
 */
package com.redhat.rhn.frontend.action.channel.ssm;

import com.redhat.rhn.common.messaging.MessageQueue;
import com.redhat.rhn.domain.channel.Channel;
import com.redhat.rhn.domain.channel.ChannelFactory;
import com.redhat.rhn.domain.rhnset.RhnSet;
import com.redhat.rhn.domain.rhnset.RhnSetElement;
import com.redhat.rhn.domain.user.User;
import com.redhat.rhn.frontend.events.SsmChangeChannelSubscriptionsEvent;
import com.redhat.rhn.frontend.struts.RequestContext;
import com.redhat.rhn.frontend.struts.RhnAction;
import com.redhat.rhn.frontend.struts.RhnHelper;
import com.redhat.rhn.frontend.taglibs.list.helper.ListHelper;
import com.redhat.rhn.frontend.taglibs.list.helper.Listable;
import com.redhat.rhn.manager.channel.ChannelManager;
import com.redhat.rhn.manager.rhnset.RhnSetDecl;
import com.redhat.rhn.manager.ssm.SsmOperationManager;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.DynaActionForm;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * ChildChannelConfirmAction
 * @version $Rev$
 */
public class ChildChannelConfirmAction extends RhnAction implements Listable {

    private final Log log = LogFactory.getLog(this.getClass());

    /**
     * {@inheritDoc}
     */
    public ActionForward execute(ActionMapping mapping,
            ActionForm form,
            HttpServletRequest request,
            HttpServletResponse response) {

        long overallStart;

        overallStart = System.currentTimeMillis();

        RequestContext requestContext = new RequestContext(request);
        User user = requestContext.getCurrentUser();
        DynaActionForm daForm = (DynaActionForm)form;

        // First, find the channels the user chose to operate on, as stored
        // in an RhnSet by ChildChannelAction
        List<Channel> chanSubList = new ArrayList<Channel>();
        List<Channel> chanUnsubList = new ArrayList<Channel>();

        findChannelsFromSet(user, chanSubList, chanUnsubList);


        chanSubList = filterChannels(chanSubList, user);
        Map<Long, ChannelActionDAO> sysSubList = ChannelManager.filterChildSubscriptions(
                RhnSetDecl.SYSTEMS.getLabel(),  chanSubList, chanUnsubList, user);

        List list = new ArrayList();
        list.addAll(sysSubList.values());
        request.setAttribute("data", list);


        ListHelper helper = new ListHelper(this, request);
        helper.execute();

        ActionForward result;
        if (isSubmitted(daForm)) {

            long operationId = SsmOperationManager.createOperation(user,
                    "ssm.subscription.operation.label", null);

            SsmOperationManager.associateServersWithOperation(operationId, user.getId(),
                    new ArrayList<Long>(sysSubList.keySet()));

            // Fire the request off asynchronously
            SsmChangeChannelSubscriptionsEvent event =
                    new SsmChangeChannelSubscriptionsEvent(user, sysSubList.values(),
                            operationId);
            MessageQueue.publish(event);

            result = mapping.findForward("success");
        }
        else {
            result = mapping.findForward(RhnHelper.DEFAULT_FORWARD);
        }

        log.debug("Overall time to run: " + (System.currentTimeMillis() - overallStart));

        return result;
    }



    protected List<Channel> filterChannels(Collection<Channel> chans, User user) {
        List<Channel> newChannels = new ArrayList<Channel>();
        for (Channel c : chans) {
            // Check for proxy and satellite channels
            if (c.isProxy() || c.isSatellite()) {
                continue;
            }
            // Verify the user roles, caching the role for the channel
            Boolean hasAcceptableRole =
                    ChannelManager.verifyChannelSubscribe(user, c.getId());
            if (hasAcceptableRole) {
                newChannels.add(c);
            }
        }
        return newChannels;
    }

    //
    // Build the list of channels we're going to unsubscribe systems from - per system,
    // we only unsubscribe if the system currently IS subscribed...
    //
    // Create Map<System,List<Channel>> allowed-unsubs
    //   Foreach chan-id in unsubscribe-list:
    //     If system-subscribed-to-channel:
    //       Channel chanel = getChannel(id)
    //       allowed-unsubs.get(system).add(channel)
    // Extract the list of subscribe and unsubscribed channels from the RhNSet that
    // was saved from the child-list page
    protected void findChannelsFromSet(User u, List<Channel> subs, List<Channel> unsubs) {
        RhnSet cset = RhnSetDecl.SSM_CHANNEL_LIST.get(u);
        Iterator itr = cset.getElements().iterator();
        while (itr.hasNext()) {
            RhnSetElement rse = (RhnSetElement)itr.next();
            Channel c = ChannelFactory.lookupById(rse.getElement());
            if (rse.getElementTwo().equals(ChannelActionDAO.SUBSCRIBE)) {
                subs.add(c);
            }
            else {
                unsubs.add(c);
            }
        }
    }



    /**
     *
     * {@inheritDoc}
     */
    public List getResult(RequestContext context) {
        return (List) context.getRequest().getAttribute("data");
    }
}