/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * ----------------

 * Millisecond.java

 * ----------------

 * (C) Copyright 2001-2003, by Object Refinery Limited.

 *

 * Original Author:  David Gilbert (for Object Refinery Limited);

 * Contributor(s):   -;

 *

 * $Id: Millisecond.java,v 1.1 2004/08/31 15:34:17 mungady Exp $

 *

 * Changes

 * -------

 * 11-Oct-2001 : Version 1 (DG);

 * 19-Dec-2001 : Added new constructors as suggested by Paul English (DG);

 * 26-Feb-2002 : Added new getStart(...) and getEnd(...) methods (DG);

 * 29-Mar-2002 : Fixed bug in getStart(...), getEnd(...) and compareTo(...) methods (DG);

 * 10-Sep-2002 : Added getSerialIndex() method (DG);

 * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);

 * 10-Jan-2003 : Changed base class and method names (DG);

 * 13-Mar-2003 : Moved to com.jrefinery.data.time package and implemented Serializable (DG);

 * 21-Oct-2003 : Added hashCode() method (DG);

 *

 */



package org.jfree.data.time;



import java.io.Serializable;

import java.util.Calendar;

import java.util.Date;

import java.util.TimeZone;



/**

 * Represents a millisecond.

 * <P>

 * This class is immutable, which is a requirement for all {@link RegularTimePeriod} subclasses.

 *

 */

public class Millisecond extends RegularTimePeriod implements Serializable {



    /** A constant for the first millisecond in a second. */

    public static final int FIRST_MILLISECOND_IN_SECOND = 0;



    /** A constant for the last millisecond in a second. */

    public static final int LAST_MILLISECOND_IN_SECOND = 999;



    /** The millisecond. */

    private int millisecond;



    /** The second. */

    private Second second;



    /**

     * Constructs a millisecond based on the current system time.

     */

    public Millisecond() {

        this(new Date());

    }



    /**

     * Constructs a millisecond.

     *

     * @param millisecond  the millisecond (0-999).

     * @param second  the second.

     */

    public Millisecond(final int millisecond, final Second second) {



        this.millisecond = millisecond;

        this.second = second;



    }



    /**

     * Creates a new millisecond.

     * 

     * @param millisecond  the millisecond (0-999).

     * @param second  the second (0-59).

     * @param minute  the minute (0-59).

     * @param hour  the hour (0-23).

     * @param day  the day (1-31).

     * @param month  the month (1-12).

     * @param year  the year (1900-9999).

     */    

    public Millisecond(final int millisecond, final int second, final int minute, final int hour,

                       final int day, final int month, final int year) {

                           

        this(millisecond, new Second(second, minute, hour, day, month, year));

    

    }



    /**

     * Constructs a millisecond.

     *

     * @param time  the time.

     */

    public Millisecond(final Date time) {

        this(time, RegularTimePeriod.DEFAULT_TIME_ZONE);

    }



    /**

     * Creates a millisecond.

     *

     * @param time  the instant in time.

     * @param zone  the time zone.

     */

    public Millisecond(final Date time, final TimeZone zone) {



        this.second = new Second(time, zone);



        final Calendar calendar = Calendar.getInstance(zone);

        calendar.setTime(time);

        this.millisecond = calendar.get(Calendar.MILLISECOND);



    }



    /**

     * Returns the second.

     *

     * @return The second.

     */

    public Second getSecond() {

        return this.second;

    }



    /**

     * Returns the millisecond.

     *

     * @return the millisecond.

     */

    public long getMillisecond() {

        return this.millisecond;

    }



    /**

     * Returns the millisecond preceding this one.

     *

     * @return the millisecond preceding this one.

     */

    public RegularTimePeriod previous() {



        RegularTimePeriod result = null;



        if (this.millisecond != FIRST_MILLISECOND_IN_SECOND) {

            result = new Millisecond(this.millisecond - 1, this.second);

        }

        else {

            final Second previous = (Second) this.second.previous();

            if (previous != null) {

                result = new Millisecond(LAST_MILLISECOND_IN_SECOND, previous);

            }

        }

        return result;



    }



    /**

     * Returns the millisecond following this one.

     *

     * @return the millisecond following this one.

     */

    public RegularTimePeriod next() {



        RegularTimePeriod result = null;



        if (this.millisecond != LAST_MILLISECOND_IN_SECOND) {

            result = new Millisecond(this.millisecond + 1, this.second);

        }

        else {

            final Second next = (Second) this.second.next();

            if (next != null) {

                result = new Millisecond(FIRST_MILLISECOND_IN_SECOND, next);

            }

        }

        return result;



    }



    /**

     * Returns a serial index number for the millisecond.

     *

     * @return The serial index number.

     */

    public long getSerialIndex() {

        return this.second.getSerialIndex() * 1000L + this.millisecond;

    }



    /**

     * Tests the equality of this object against an arbitrary Object.

     * <P>

     * This method will return true ONLY if the object is a Millisecond object

     * representing the same millisecond as this instance.

     *

     * @param object  the object to compare

     *

     * @return <code>true</code> if milliseconds and seconds of this and object

     *      are the same.

     */

    public boolean equals(final Object object) {



        if (object instanceof Millisecond) {

            final Millisecond m = (Millisecond) object;

            return ((this.millisecond == m.getMillisecond())

                    && (this.second.equals(m.getSecond())));

        }

        else {

            return false;

        }



    }



    /**

     * Returns a hash code for this object instance.

     * <p>

     * The approach described by Joshua Bloch in "Effective Java" has been used here:

     * <p>

     * <code>http://developer.java.sun.com/developer/Books/effectivejava/Chapter3.pdf</code>

     * 

     * @return A hashcode.

     */

    public int hashCode() {

        int result = 17;

        result = 37 * result + this.millisecond;

        result = 37 * result + this.second.hashCode();

        return result;

    }



    /**

     * Returns an integer indicating the order of this Millisecond object

     * relative to the specified object:

     *

     * negative == before, zero == same, positive == after.

     *

     * @param o1  the object to compare

     *

     * @return negative == before, zero == same, positive == after.

     */

    public int compareTo(final Object o1) {



        final int result;

        final long difference;



        // CASE 1 : Comparing to another Second object

        // -------------------------------------------

        if (o1 instanceof Millisecond) {

            final Millisecond ms = (Millisecond) o1;

            difference = getFirstMillisecond() - ms.getFirstMillisecond();

            if (difference > 0) {

                result = 1;

            }

            else {

                if (difference < 0) {

                    result = -1;

                }

                else {

                    result = 0;

                }

            }

        }



        // CASE 2 : Comparing to another TimePeriod object

        // -----------------------------------------------

        else if (o1 instanceof RegularTimePeriod) {

            // more difficult case - evaluate later...

            result = 0;

        }



        // CASE 3 : Comparing to a non-TimePeriod object

        // ---------------------------------------------

        else {

            // consider time periods to be ordered after general objects

            result = 1;

        }



        return result;



    }



    /**

     * Returns the first millisecond of the time period.

     *

     * @return the first millisecond of the time period.

     */

    public long getFirstMillisecond() {

        return this.second.getFirstMillisecond() + this.millisecond;

    }



    /**

     * Returns the first millisecond of the time period.

     *

     * @param calendar  the calendar.

     *

     * @return the first millisecond of the time period.

     */

    public long getFirstMillisecond(final Calendar calendar) {



        return this.second.getFirstMillisecond(calendar) + this.millisecond;



    }



    /**

     * Returns the last millisecond of the time period.

     *

     * @return the last millisecond of the time period.

     */

    public long getLastMillisecond() {

        return this.second.getFirstMillisecond() + this.millisecond;

    }



    /**

     * Returns the last millisecond of the time period.

     *

     * @param calendar  the calendar.

     *

     * @return the last millisecond of the time period.

     */

    public long getLastMillisecond(final Calendar calendar) {



        return this.second.getFirstMillisecond(calendar) + this.millisecond;



    }



}

