/*
 * ====================================================================== Parts
 * Copyright 2006 University of Leeds, Oxford University, University of the
 * Highlands and Islands. Licensed under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law
 * or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 * ======================================================================
 */

package org.bodington.installation;

import java.util.Enumeration;

import org.apache.log4j.Logger;
import org.bodington.server.BuildingServerException;
import org.bodington.server.BuildingSessionManagerImpl;
import org.bodington.server.JobScheduler;
import org.bodington.server.JobSession;
import org.bodington.server.QuotaFactory;
import org.bodington.server.QuotaMetadatum;
import org.bodington.server.UploadedFileSession;
import org.bodington.server.resources.Resource;
import org.bodington.server.resources.ResourceTreeManager;

/**
 * Walk the whole of the resource tree checking that the quota is correct.
 * @author buckett
 */
public class QuotaRecalculation implements JobSession
{
    private static Logger log = Logger.getLogger(QuotaRecalculation.class);
    
    private int resourcesProcessed = 0;

    public void recalculate(String args)
    {
        try
        {
            log.info("Started recalculation");
            Resource start = null;
            try
            {
                start = ResourceTreeManager.getInstance().findResource(new String[]{"users"});
            }
            catch (BuildingServerException bse)
            {
                log.info("Couldn't find /users resource");
            }
            checkResource(start);
            log.info("Finished recalculation ("+ resourcesProcessed+ ")");
        }
        catch (BuildingServerException bse)
        {
            log.error("Problem recalculating quota.", bse);
        }
    }

    public void checkResource(Resource resource) throws BuildingServerException
    {
        if (resource == null)
        {
            return;
        }
        UploadedFileSession session = BuildingSessionManagerImpl.getSession(
            resource).getUploadedFileSession();
        try
        {
            session.checkFileQuota();
            resourcesProcessed++;
            if (resourcesProcessed % 1000 == 0)
            {
                log.debug("Processed "+ resourcesProcessed+ " resources.");
            }
        }
        catch (BuildingServerException bse)
        {
            log.warn("Failed to recalculate quota for "+ resource.getFullName(), bse);
        }
        QuotaMetadatum quota = QuotaFactory.getQuota(resource, QuotaFactory.FILES);
        // Only do children if we don't have quota.
        if (!quota.hasQuota()) {
            for (Enumeration children = resource.findChildren(); children
            .hasMoreElements();)
            {
                checkResource((Resource) children.nextElement());
            }
        }

    }

    public static void addJob()
    {
        try
        {
            JobScheduler.getJobScheduler(true).addJobOnce(
                QuotaRecalculation.class.getName(), "recalculate");
        }
        catch (BuildingServerException bse)
        {
            log.error("Problem finding job or adding a new one.", bse);
        }
    }

}