/*
 * Copyright 2012-2017 Red Hat, Inc.
 *
 * This file is part of Thermostat.
 *
 * Thermostat is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2, or (at your
 * option) any later version.
 *
 * Thermostat 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 Thermostat; see the file COPYING.  If not see
 * <http://www.gnu.org/licenses/>.
 *
 * Linking this code with other modules is making a combined work
 * based on this code.  Thus, the terms and conditions of the GNU
 * General Public License cover the whole combination.
 *
 * As a special exception, the copyright holders of this code give
 * you permission to link this code with independent modules to
 * produce an executable, regardless of the license terms of these
 * independent modules, and to copy and distribute the resulting
 * executable under terms of your choice, provided that you also
 * meet, for each linked independent module, the terms and conditions
 * of the license of that module.  An independent module is a module
 * which is not derived from or based on this code.  If you modify
 * this code, you may extend this exception to your version of the
 * library, but you are not obligated to do so.  If you do not wish
 * to do so, delete this exception statement from your version.
 */

package com.redhat.thermostat.thread.harvester;

import com.redhat.thermostat.common.SystemClock;
import com.redhat.thermostat.storage.core.WriterID;
import com.redhat.thermostat.thread.dao.ThreadDao;
import com.redhat.thermostat.thread.model.VmDeadLockData;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;

/**
 */
public class DeadlockHelper {

    private final ThreadDao threadDao;
    private final SystemClock systemClock;
    private final String vmId;
    private final WriterID id;

    public DeadlockHelper(ThreadDao threadDao, SystemClock systemClock,
                          String vmId, WriterID id)
    {
        this.threadDao = threadDao;
        this.systemClock = systemClock;
        this.vmId = vmId;
        this.id = id;
    }

    void saveDeadlockInformation(ThreadMXBean collector) {
        String description = null;
        long timeStamp = systemClock.getRealTimeMillis();
        long[] ids = collector.findDeadlockedThreads();
        if (ids == null) {
            description = VmDeadLockData.NO_DEADLOCK;
        } else {
            ThreadInfo[] infos = collector.getThreadInfo(ids, true, true);
            StringBuilder descriptionBuilder = new StringBuilder();
            for (ThreadInfo info : infos) {
                descriptionBuilder.append(info.toString()).append("\n");
            }
            description = descriptionBuilder.toString();
        }

        String wId = id.getWriterID();
        VmDeadLockData data = new VmDeadLockData(wId);
        data.setTimeStamp(timeStamp);
        data.setVmId(vmId);
        data.setDeadLockDescription(description);

        threadDao.saveDeadLockStatus(data);
    }
}