/**
 * Copyright (c) 2009--2012 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.taskomatic.task;

import com.redhat.rhn.common.conf.Config;
import com.redhat.rhn.common.db.datasource.DataResult;
import com.redhat.rhn.common.db.datasource.ModeFactory;
import com.redhat.rhn.common.db.datasource.SelectMode;
import com.redhat.rhn.common.db.datasource.WriteMode;

import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;

import java.io.File;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * Cleans up orphaned packages
 *
 * @version $Rev $
 */

public class PackageCleanup extends RhnJavaJob {

    /**
     * {@inheritDoc}
     */
    public void execute(JobExecutionContext ctx) throws JobExecutionException {
        try {
            String pkgDir = Config.get().getString("web.mount_point");

            // Retrieve list of orpahned packages
            List candidates = findCandidates();

            // Bail if no work to do
            if (candidates == null || candidates.size() == 0) {
                if (log.isDebugEnabled()) {
                    log.debug("No orphaned packages found");
                }
            }
            else if (log.isDebugEnabled()) {
                log.debug("Found " + candidates.size() + " orphaned packages");
            }

            // Delete them from the filesystem
            for (Iterator iter = candidates.iterator(); iter.hasNext();) {
                Map row = (Map) iter.next();
                String path = (String) row.get("path");
                if (log.isDebugEnabled()) {
                    log.debug("Deleting package " + path);
                }
                if (path == null) {
                    continue;
                }
                deletePackage(pkgDir, path);
            }

            // Reset the queue (table)
            resetQueue();
        }
        catch (Exception e) {
            log.error(e.getMessage(), e);
            throw new JobExecutionException(e);
        }
    }

    private void resetQueue() {
        WriteMode update = ModeFactory.getWriteMode(TaskConstants.MODE_NAME,
                TaskConstants.TASK_QUERY_PKGCLEANUP_RESET_QUEUE);
        update.executeUpdate(Collections.EMPTY_MAP);
    }

    private void deletePackage(String pkgDir, String path) {
        File f = new File(pkgDir, path);
        if (f.exists() && f.canWrite() && !f.isDirectory()) {
            f.delete();
            if (log.isDebugEnabled()) {
                log.debug("Deleting " + f.getAbsoluteFile());
            }

            // Remove parents but only within path, and keep two top directories
            File pathFile = new File(path);
            File parent;
            do {
                pathFile = pathFile.getParentFile();
                if (pathFile == null ||
                        pathFile.getParentFile() == null ||
                            pathFile.getParentFile().getParentFile() == null) {
                    break;
                }
                parent = new File(pkgDir, pathFile.getPath());
            }
            while (parent.delete());
        }
        else {
            log.error(f.getAbsoluteFile() + " not found");
        }
    }

    private List findCandidates() {
        SelectMode query = ModeFactory.getMode(TaskConstants.MODE_NAME,
                TaskConstants.TASK_QUERY_PKGCLEANUP_FIND_CANDIDATES);
        DataResult dr = query.execute(Collections.EMPTY_MAP);
        return dr;
    }

}