/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------
 * TimeSeries.java
 * ---------------
 * (C) Copyright 2001-2005, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Bryan Scott;
 *
 * $Id: TimeSeries.java,v 1.10.2.6 2005/12/01 22:03:07 mungady Exp $
 *
 * Changes
 * -------
 * 11-Oct-2001 : Version 1 (DG);
 * 14-Nov-2001 : Added listener mechanism (DG);
 * 15-Nov-2001 : Updated argument checking and exceptions in add() method (DG);
 * 29-Nov-2001 : Added properties to describe the domain and range (DG);
 * 07-Dec-2001 : Renamed TimeSeries --> BasicTimeSeries (DG);
 * 01-Mar-2002 : Updated import statements (DG);
 * 28-Mar-2002 : Added a method add(TimePeriod, double) (DG);
 * 27-Aug-2002 : Changed return type of delete method to void (DG);
 * 04-Oct-2002 : Added itemCount and historyCount attributes, fixed errors 
 *               reported by Checkstyle (DG);
 * 29-Oct-2002 : Added series change notification to addOrUpdate() method (DG);
 * 28-Jan-2003 : Changed name back to TimeSeries (DG);
 * 13-Mar-2003 : Moved to com.jrefinery.data.time package and implemented 
 *               Serializable (DG);
 * 01-May-2003 : Updated equals() method (see bug report 727575) (DG);
 * 14-Aug-2003 : Added ageHistoryCountItems method (copied existing code for 
 *               contents) made a method and added to addOrUpdate.  Made a 
 *               public method to enable ageing against a specified time 
 *               (eg now) as opposed to lastest time in series (BS);
 * 15-Oct-2003 : Added fix for setItemCount method - see bug report 804425.  
 *               Modified exception message in add() method to be more 
 *               informative (DG);
 * 13-Apr-2004 : Added clear() method (DG);
 * 21-May-2004 : Added an extra addOrUpdate() method (DG);
 * 15-Jun-2004 : Fixed NullPointerException in equals() method (DG);
 * 29-Nov-2004 : Fixed bug 1075255 (DG);
 * 17-Nov-2005 : Renamed historyCount --> maximumItemAge (DG);
 * 28-Nov-2005 : Changed maximumItemAge from int to long (DG);
 * 01-Dec-2005 : New add methods accept notify flag (DG);
 * 
 */

package org.jfree.data.time;

import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import org.jfree.data.general.Series;
import org.jfree.data.general.SeriesChangeEvent;
import org.jfree.data.general.SeriesException;
import org.jfree.util.ObjectUtilities;

/**
 * Represents a sequence of zero or more data items in the form (period, value).
 */
public class TimeSeries extends Series implements Cloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -5032960206869675528L;
    
    /** Default value for the domain description. */
    protected static final String DEFAULT_DOMAIN_DESCRIPTION = "Time";

    /** Default value for the range description. */
    protected static final String DEFAULT_RANGE_DESCRIPTION = "Value";

    /** A description of the domain. */
    private String domain;

    /** A description of the range. */
    private String range;

    /** The type of period for the data. */
    protected Class timePeriodClass;

    /** The list of data items in the series. */
    protected List data;

    /** The maximum number of items for the series. */
    private int maximumItemCount;

    /** The maximum age of items for the series. */
    private long maximumItemAge;
    
    /**
     * Creates a new (empty) time series.  By default, a daily time series is 
     * created.  Use one of the other constructors if you require a different 
     * time period.
     *
     * @param name  the series name (<code>null</code> not permitted).
     */
    public TimeSeries(String name) {
        this(
            name, DEFAULT_DOMAIN_DESCRIPTION, DEFAULT_RANGE_DESCRIPTION, 
            Day.class
        );
    }

    /**
     * Creates a new (empty) time series.
     *
     * @param name  the series name (<code>null</code> not permitted).
     * @param timePeriodClass  the type of time period (<code>null</code> not 
     *                         permitted).
     */
    public TimeSeries(String name, Class timePeriodClass) {
        this(
            name, DEFAULT_DOMAIN_DESCRIPTION, DEFAULT_RANGE_DESCRIPTION, 
            timePeriodClass
        );
    }

    /**
     * Creates a new time series that contains no data.
     * <P>
     * Descriptions can be specified for the domain and range.  One situation
     * where this is helpful is when generating a chart for the time series -
     * axis labels can be taken from the domain and range description.
     *
     * @param name  the name of the series (<code>null</code> not permitted).
     * @param domain  the domain description (<code>null</code> permitted).
     * @param range  the range description (<code>null</code> permitted).
     * @param timePeriodClass  the type of time period (<code>null</code> not 
     *                         permitted).
     */
    public TimeSeries(String name, String domain, String range, 
                      Class timePeriodClass) {

        super(name);
        this.domain = domain;
        this.range = range;
        this.timePeriodClass = timePeriodClass;
        this.data = new java.util.ArrayList();
        this.maximumItemCount = Integer.MAX_VALUE;
        this.maximumItemAge = Long.MAX_VALUE;
        
    }

    /**
     * Returns the domain description.
     *
     * @return The domain description (possibly <code>null</code>).
     */
    public String getDomainDescription() {
        return this.domain;
    }

    /**
     * Sets the domain description.
     * <P>
     * A property change event is fired, and an undoable edit is posted.
     *
     * @param description  the description (<code>null</code> permitted).
     */
    public void setDomainDescription(String description) {
        String old = this.domain;
        this.domain = description;
        firePropertyChange("Domain", old, description);
    }

    /**
     * Returns the range description.
     *
     * @return The range description (possibly <code>null</code>).
     */
    public String getRangeDescription() {
        return this.range;
    }

    /**
     * Sets the range description and fires a property change event for the 
     * 'Range' property.
     *
     * @param description  the description (<code>null</code> permitted).
     */
    public void setRangeDescription(String description) {
        String old = this.range;
        this.range = description;
        firePropertyChange("Range", old, description);
    }

    /**
     * Returns the number of items in the series.
     *
     * @return The item count.
     */
    public int getItemCount() {
        return this.data.size();
    }

    /**
     * Returns the list of data items for the series (the list contains 
     * {@link TimeSeriesDataItem} objects and is unmodifiable).
     *
     * @return The list of data items.
     */
    public List getItems() {
        return Collections.unmodifiableList(this.data);
    }

    /**
     * Returns the maximum number of items that will be retained in the series.
     * The default value is <code>Integer.MAX_VALUE</code>.
     *
     * @return The maximum item count.
     * 
     * @see #setMaximumItemCount(int)
     */
    public int getMaximumItemCount() {
        return this.maximumItemCount;
    }

    /**
     * Sets the maximum number of items that will be retained in the series.  
     * If you add a new item to the series such that the number of items will 
     * exceed the maximum item count, then the FIRST element in the series is 
     * automatically removed, ensuring that the maximum item count is not 
     * exceeded.
     *
     * @param maximum  the maximum (requires >= 0).
     * 
     * @see #getMaximumItemCount()
     */
    public void setMaximumItemCount(int maximum) {
        if (maximum < 0) {
            throw new IllegalArgumentException("Negative 'maximum' argument.");
        }
        this.maximumItemCount = maximum;
        int count = this.data.size();
        if (count > maximum) {
            delete(0, count - maximum - 1);
        }
    }

    /**
     * Returns the maximum item age (in time periods) for the series.
     *
     * @return The maximum item age.
     * 
     * @see #setMaximumItemAge(long)
     */
    public long getMaximumItemAge() {
        return this.maximumItemAge;
    }

    /**
     * Sets the number of time units in the 'history' for the series.  This 
     * provides one mechanism for automatically dropping old data from the
     * time series. For example, if a series contains daily data, you might set
     * the history count to 30.  Then, when you add a new data item, all data
     * items more than 30 days older than the latest value are automatically 
     * dropped from the series.
     *
     * @param periods  the number of time periods.
     * 
     * @see #getMaximumItemAge()
     */
    public void setMaximumItemAge(long periods) {
        if (periods < 0) {
            throw new IllegalArgumentException("Negative 'periods' argument.");
        }
        this.maximumItemAge = periods;
        removeAgedItems(true);  // remove old items and notify if necessary
    }

    /**
     * Returns the time period class for this series.
     * <p>
     * Only one time period class can be used within a single series (enforced).
     * If you add a data item with a {@link Year} for the time period, then all
     * subsequent data items must also have a {@link Year} for the time period.
     *
     * @return The time period class (never <code>null</code>).
     */
    public Class getTimePeriodClass() {
        return this.timePeriodClass;
    }

    /**
     * Returns a data item for the series.
     *
     * @param index  the item index (zero-based).
     *
     * @return The data item.
     */
    public TimeSeriesDataItem getDataItem(int index) {
        return (TimeSeriesDataItem) this.data.get(index);
    }

    /**
     * Returns the data item for a specific period.
     *
     * @param period  the period of interest (<code>null</code> not allowed).