/*
 * This file is part of the Alitheia system, developed by the SQO-OSS
 * consortium as part of the IST FP6 SQO-OSS project, number 033331.
 *
 * Copyright 2007 - 2010 - Organization for Free and Open Source Software,  
 *                Athens, Greece.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

package eu.sqooss.service.fds;

import eu.sqooss.service.db.DAObject;

/**
 * A generic data transfer object holding references to 
 * resources describing a project event.  
 * 
 */
public abstract class ProjectEvent implements Comparable<ProjectEvent> {
    
    /**
     * Second-accurate timestamp
     */
    protected long timestamp;
    
    /**
     * Database record about the event.
     */
    protected DAObject associatedDAO;
        
    /**
     * @return the associated DAO
     */
    public DAObject getAssociatedDAO() {
        return associatedDAO;
    }
    
    /**
     * This value is used as the primary sorting discriminant for events.
     * @return the timestamp in second-accuracy.
     */
    public long getTimestamp() {
        return timestamp;
    }
    
    /**
     * This value is used to further sort events with identical timestamps.
     * @return an integer representing the "priority" of the event.
     */
    protected abstract int getEventPriority();

    /**
     * This value is used to further sort elements with identical timestamps and priorities.
     * (e.g. two SCM commits happening in the same second)
     * @return an integer representing the event id.
     */
    protected abstract long getEventId();

        
    /**
     * Compare events using the following discriminants in order :
     * timestamp -> priority -> event id
     * @return -1/0/1 if the event is more prioritary/equal/less prioritary than other
     */
    public int compareTo(ProjectEvent other)
    {
        if ( getTimestamp() == other.getTimestamp() ) {
            if ( getEventPriority() == other.getEventPriority() ) {
                if ( getEventId() == other.getEventId() ) {
                    return 0;
                }
                return getEventId() > other.getEventId() ? 1 : -1;
            }
            return getEventPriority() > other.getEventPriority() ? 1 : -1;
        }
        return getTimestamp() > other.getTimestamp() ? 1 : -1;
    }
}

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