/*

         StatCvs - CVS statistics generation 

         Copyright (C) 2002  Lukasz Pekacki <lukasz@pekacki.de>

         http://statcvs.sf.net/

         This library is free software; you can redistribute it and/or

         modify it under the terms of the GNU Lesser General Public

         License as published by the Free Software Foundation; either

         version 2.1 of the License, or (at your option) any later version.

         This library 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

         Lesser General Public License for more details.

         You should have received a copy of the GNU Lesser General Public

         License along with this library; if not, write to the Free Software

         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

         $RCSfile: TimeLine.java,v $

         $Date: 2008/04/02 11:52:02 $

 */

 package net.sf.statcvs.reportmodel;

 import java.util.ArrayList;

 import java.util.Date;

 import java.util.Iterator;

 import java.util.List;

 import java.util.TreeMap;

 /**

  * Contains time line data for an integer value. The semantics is that at

  * every data point, the time line's value changed from the previous point's

  * value to the current point's value. Time points may be specified either

  * by an absolute value using <tt>addTimePoint</tt>, or by a value relative

  * to the previous time point using {@link #addChange}. If all points are

  * specified using <tt>addChange</tt>, an initial value must be given

  * using {@link #setInitialValue}.

  * 

  * @author Richard Cyganiak <rcyg@gmx.de>

  * @version $Id: TimeLine.java,v 1.5 2008/04/02 11:52:02 benoitx Exp $

  */

 public class TimeLine {

     private final TreeMap dataPoints = new TreeMap();

     private Date minimumDate = null;

     private int initialValue;

     private boolean hasInitialValue = false;

     private final String title;

     private final String rangeLabel;

     /**

      * Creates a new time line.

      * @param title the time line's title

      * @param rangeLabel a range label (axis label) for the values

      */

     public TimeLine(final String title, final String rangeLabel) {

         this.title = title;

         this.rangeLabel = rangeLabel;

     }

     /**

      * Sets the initial value of the time line, that is the value just before

      * the first data point.

      * @param initialValue the time line's initial value

      */

     public void setInitialValue(final int initialValue) {

         this.initialValue = initialValue;

         this.hasInitialValue = true;

     }

     /**

      * Adds a data point to the time line. Data points may be added in any

      * order.

      * @param date the data point's date

      * @param value the data point's value

      */

     public void addTimePoint(final Date date, final int value) {

         addTimePoint(HelperTimePoint.createAbsoluteValueTimePoint(date, value));

     }

     /**

      * Specifies that the time line's value changed at a given date. Data

      * points may be added in any order.

      * @param date the data point's date

      * @param delta the value change at this time

      */

     public void addChange(final Date date, final int delta) {

         addTimePoint(HelperTimePoint.createDeltaTimePoint(date, delta));

     }

     /**

      * Checks if the time series is empty. A series is considered empty if

      * it has zero or one time points. It takes two distinct time points

      * to actually make it a series.

      * @return <tt>true</tt> if the time series is empty

      */

     public boolean isEmpty() {

         return dataPoints.size() <= 1;

     }

     /**

      * Returns a <tt>List</tt> of data points, ordered by date.

      * @return a <tt>List</tt> of {@link TimePoint}s

      */

     public List getDataPoints() {

         List result;

         int currentValue;

         if (hasInitialValue && dataPoints.size() > 0) {

             result = new ArrayList(dataPoints.size() + 1);

             final Date beforeMinimum = new Date(minimumDate.getTime() - 1);

             result.add(new TimePoint(beforeMinimum, initialValue, 0));

             currentValue = initialValue;

         } else {

             result = new ArrayList(dataPoints.size());

             if (dataPoints.size() == 0) {

                 return result;

             }

             final HelperTimePoint firstPoint = (HelperTimePoint) dataPoints.get(dataPoints.firstKey());

             if (!firstPoint.isAbsolute()) {

                 throw new IllegalStateException("The first data point must be absolute, or setInitialValue must be used");

             }

             currentValue = firstPoint.getValue();

         }

         final Iterator it = dataPoints.values().iterator();

         while (it.hasNext()) {

             final HelperTimePoint point = (HelperTimePoint) it.next();

             if (point.isAbsolute()) {

                 final int delta = point.getValue() - currentValue;

                 result.add(new TimePoint(point.getDate(), point.getValue(), delta));

                 currentValue = point.getValue();

             } else {

                 currentValue += point.getValue();

                 result.add(new TimePoint(point.getDate(), currentValue, point.getValue()));

             }

         }

         return result;

     }

     private void addTimePoint(HelperTimePoint newPoint) {

         final HelperTimePoint oldPoint = (HelperTimePoint) dataPoints.get(newPoint.getDate());

         if (oldPoint == null) {

             if (minimumDate == null || newPoint.getDate().before(minimumDate)) {

                 minimumDate = newPoint.getDate();

             }

             //oldPoint = newPoint;

         } else {

             newPoint = oldPoint.join(newPoint);

         }

         dataPoints.put(newPoint.getDate(), newPoint);

     }

     /**

      * Returns the range label (axis label) of the values

      * @return an axis label for the values

      */

     public String getRangeLabel() {

         return rangeLabel;

     }

     /**

      * Returns the title of the time line

      * @return the title

      */

     public String getTitle() {

         return title;

     }

 }