/*
   XBN Java:  Generically useful, non-GUI Java code.
   http://sourceforge.net/projects/xbnjava

   Copyright (C) 1997-2003, Jeff Epstein
   All rights reserved.

   Modifications: No

   Redistribution in binary form, with or without modifications, are permitted provided that the following conditions are met:

      * 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.
      * If modifications are made to source code then this license should indicate that fact in the "Modifications" section above.
      * Neither the author, nor the contributors may be used to endorse or promote products derived from this software without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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.

   [NOTE:  This license contains NO advertising clause.]
 */
package xbn.util;
   import xbn.XBNObject;

   import java.util.Date;

/**
   <P>Random functions for analyzing and manipulating java.util.Dates.  See java.util.<A HREF="~JD~jud~EJD~">Date</A>.</P>

   <P><CODE><I><B>Source code:</B> &nbsp;<A HREF="../../../CODE/xbn/util/UtilDate.java">UtilDate.java</A>.</I></CODE></P>

   @version  0.9b
   @author  Jeff Epstein, <A HREF="http://sourceforge.net/projects/xbnjava">http://sourceforge.net/projects/xbnjava</A>.
 **/
public class UtilDate extends XBNObject  {

   /**
      <P>Create a UtilDate.  This constructor does nothing.</P>
    **/
   public UtilDate()  {
   }

   /**
      <P>Get a Date that is X seconds before <I>now</I>.</P>

      @return <CODE><A HREF="~JD~getDateXBeforeNow(l,i)~EJD~">getDateXBeforeNow</A>(<A HREF="#getMillsInASecond()">getMillsInASecond</A>(), i_unitsAgo)</CODE>
    **/
   public final Date getDateXBNSeconds(int i_unitsAgo)  {
      return getDateXBeforeNow(getMillsInASecond(), i_unitsAgo);
   }

   /**
      <P>Get a Date that is X minutes before <I>now</I>.</P>

      @return <CODE><A HREF="~JD~getDateXBeforeNow(l,i)~EJD~">getDateXBeforeNow</A>(<A HREF="#getMillsInAMinute()">getMillsInAMinute</A>(), i_unitsAgo)</CODE>
    **/
   public final Date getDateXBNMinutes(int i_unitsAgo)  {
      return getDateXBeforeNow(getMillsInAMinute(), i_unitsAgo);
   }

   /**
      <P>Get a Date that is X hours before <I>now</I>.</P>

      @return <CODE><A HREF="~JD~getDateXBeforeNow(l,i)~EJD~">getDateXBeforeNow</A>(<A HREF="#getMillsInAMinute()">getMillsInAMinute</A>(), i_unitsAgo)</CODE>
    **/
   public final Date getDateXBNHours(int i_unitsAgo)  {
      return getDateXBeforeNow(getMillsInAMinute(), i_unitsAgo);
   }

   /**
      <P>Get a Date that is X days before <I>now</I>.</P>

      @return <CODE><A HREF="~JD~getDateXBeforeNow(l,i)~EJD~">getDateXBeforeNow</A>(<A HREF="#getMillsInADay()">getMillsInADay</A>(), i_unitsAgo)</CODE>
    **/
   public final Date getDateXBNDays(int i_unitsAgo)  {
      return getDateXBeforeNow(getMillsInADay(), i_unitsAgo);
   }

   /**
      <P>Get a Date that is X weeks before <I>now</I>.</P>

      @return <CODE><A HREF="~JD~getDateXBeforeNow(l,i)~EJD~">getDateXBeforeNow</A>(<A HREF="#getMillsInAWeek()">getMillsInAWeek</A>(), i_unitsAgo)</CODE>
    **/
   public final Date getDateXBNWeeks(int i_unitsAgo)  {
      return getDateXBeforeNow(getMillsInAWeek(), i_unitsAgo);
   }

   /**
      <P>Get a Date that is X units before <I>now</I>.</P>

      @return <CODE><A HREF="~JD~getDateXAgo(l,i,jud)~EJD~">getDateXAgo</A>(l_multiplier, i_unitsAgo, (new <A HREF="~JD~jud#jud()~EJD~">Date</A>()))</CODE>
    **/
   public final Date getDateXBeforeNow(long l_multiplier, int i_unitsAgo)  {
      return getDateXAgo(l_multiplier, i_unitsAgo, (new Date()));
   }

   /**
      <P>Get a Date that is X seconds before the provided date.</P>

      @return <CODE><A HREF="~JD~getDateXAgo(l,i,jud)~EJD~">getDateXAgo</A>(<A HREF="#getMillsInASecond()">getMillsInASecond</A>(), i_unitsAgo, d_from)</CODE>
    **/
   public final Date getDateXAgoSeconds(int i_unitsAgo, Date d_from)  {
      return getDateXAgo(getMillsInASecond(), i_unitsAgo, d_from);
   }

   /**
      <P>Get a Date that is X minutes before the provided date.</P>

      @return <CODE><A HREF="~JD~getDateXAgo(l,i,jud)~EJD~">getDateXAgo</A>(<A HREF="#getMillsInAMinute()">getMillsInAMinute</A>(), i_unitsAgo, d_from)</CODE>
    **/
   public final Date getDateXAgoMinutes(int i_unitsAgo, Date d_from)  {
      return getDateXAgo(getMillsInAMinute(), i_unitsAgo, d_from);
   }

   /**
      <P>Get a Date that is X hours before the provided date.</P>

      @return <CODE><A HREF="~JD~getDateXAgo(l,i,jud)~EJD~">getDateXAgo</A>(<A HREF="#getMillsInAMinute()">getMillsInAMinute</A>(), i_unitsAgo, d_from)</CODE>
    **/
   public final Date getDateXAgoHours(int i_unitsAgo, Date d_from)  {
      return getDateXAgo(getMillsInAMinute(), i_unitsAgo, d_from);
   }

   /**
      <P>Get a Date that is X days before the provided date.</P>

      @return <CODE><A HREF="~JD~getDateXAgo(l,i,jud)~EJD~">getDateXAgo</A>(<A HREF="#getMillsInADay()">getMillsInADay</A>(), i_unitsAgo, d_from)</CODE>
    **/
   public final Date getDateXAgoDays(int i_unitsAgo, Date d_from)  {
      return getDateXAgo(getMillsInADay(), i_unitsAgo, d_from);
   }

   /**
      <P>Get a Date that is X weeks before the provided date.</P>

      @return <CODE><A HREF="~JD~getDateXAgo(l,i,jud)~EJD~">getDateXAgo</A>(<A HREF="#getMillsInAWeek()">getMillsInAWeek</A>(), i_unitsAgo, d_from)</CODE>
    **/
   public final Date getDateXAgoWeeks(int i_unitsAgo, Date d_from)  {
      return getDateXAgo(getMillsInAWeek(), i_unitsAgo, d_from);
   }

   /**
      <P>Get a Date that is X units before the provided date.</P>

      @param  l_multiplier  The number used to translate a Date's milleseconds to some other unit.  May not be zero.
      @param  i_unitsAgo  The number of "units ago" you want the returned date to be, in relation to d_from.
      @param  d_from  The date that you want to count back from.  May not be null.

      @return <CODE>new <A HREF="~JD~jud#jud(l)~EJD~">Date</A>(d_from.getTime() - (i_unitsAgo / l_multiplier))</CODE>
    **/
   public final Date getDateXAgo(long l_multiplier, int i_unitsAgo, Date d_from)  {
      throwAXIfNull(d_from, "d_from", "getDateXAgo");
      if(l_multiplier == 0)  {
         throwAX("getXMinusYUnits:  l_multiplier is zero.");
      }

      return new Date(d_from.getTime() - (i_unitsAgo / l_multiplier));
   }

   /**
      <P>How many seconds before <I>now</I> is the provided date?</P>

      @return  <CODE><A HREF="~JD~getNowMinusYUnits(jud,l)~EJD~">getNowMinusYUnits</A>(d_y, <A HREF="#getMillsInASecond()">getMillsInASecond</A>())</CODE>
    **/
   public final int getNowMinusYSeconds(Date d_y)  {
      return getNowMinusYUnits(d_y, getMillsInASecond());
   }

   /**
      <P>How many minutes before <I>now</I> is the provided date?</P>

      @return  <CODE><A HREF="~JD~getNowMinusYUnits(jud,l)~EJD~">getNowMinusYUnits</A>(d_y, <A HREF="#getMillsInAMinute()">getMillsInAMinute</A>())</CODE>
    **/
   public final int getNowMinusYMinutes(Date d_y)  {
      return getNowMinusYUnits(d_y, getMillsInAMinute());
   }

   /**
      <P>How many hours before <I>now</I> is the provided date?</P>

      @return  <CODE><A HREF="~JD~getNowMinusYUnits(jud,l)~EJD~">getNowMinusYUnits</A>(d_y, <A HREF="#getMillsInAnHour()">getMillsInAnHour</A>())</CODE>
    **/
   public final int getNowMinusYHours(Date d_y)  {
      return getNowMinusYUnits(d_y, getMillsInAnHour());
   }

   /**
      <P>How many days before <I>now</I> is the provided date?</P>

      @return  <CODE><A HREF="~JD~getNowMinusYUnits(jud,l)~EJD~">getNowMinusYUnits</A>(d_y, <A HREF="#getMillsInADay()">getMillsInADay</A>())</CODE>
    **/
   public final int getNowMinusYDays(Date d_y)  {
      return getNowMinusYUnits(d_y, getMillsInADay());
   }

   /**
      <P>How many weeks before <I>now</I> is the provided date?</P>

      @return  <CODE><A HREF="~JD~getNowMinusYUnits(jud,l)~EJD~">getNowMinusYUnits</A>(d_y, <A HREF="#getMillsInAWeek()">getMillsInAWeek</A>())</CODE>
    **/
   public final int getNowMinusYWeeks(Date d_y)  {
      return getNowMinusYUnits(d_y, getMillsInAWeek());
   }

   /**
      <P>How many units before <I>now</I> is the provided date?</P>

      @return  <CODE><A HREF="~JD~getXMinusYUnits(jud,jud,l)~EJD~">getXMinusYUnits</A>((new <A HREF="~JD~jud#jud()~EJD~">Date</A>()), d_y, l_multiplier)</CODE>
    **/
   public final int getNowMinusYUnits(Date d_y, long l_multiplier)  {
      return getXMinusYUnits((new Date()), d_y, l_multiplier);
   }

   /**
      <P>How many seconds separate the provided dates?</P>

      @return  <CODE><A HREF="~JD~getXMinusYUnits(jud,jud,l)~EJD~">getXMinusYUnits</A>(d_x, d_y, <A HREF="#getMillsInASecond()">getMillsInASecond</A>())</CODE>
    **/
   public final int getXMinusYSeconds(Date d_x, Date d_y)  {
      return getXMinusYUnits(d_x, d_y, getMillsInASecond());
   }

   /**
      <P>How many minutes separate the provided dates?</P>

      @return  <CODE><A HREF="~JD~getXMinusYUnits(jud,jud,l)~EJD~">getXMinusYUnits</A>(d_x, d_y, <A HREF="#getMillsInAMinute()">getMillsInAMinute</A>())</CODE>
    **/
   public final int getXMinusYMinutes(Date d_x, Date d_y)  {
      return getXMinusYUnits(d_x, d_y, getMillsInAMinute());
   }

   /**
      <P>How many hours separate the provided dates?</P>

      @return  <CODE><A HREF="~JD~getXMinusYUnits(jud,jud,l)~EJD~">getXMinusYUnits</A>(d_x, d_y, <A HREF="#getMillsInAnHour()">getMillsInAnHour</A>())</CODE>
    **/
   public final int getXMinusYHours(Date d_x, Date d_y)  {
      return getXMinusYUnits(d_x, d_y, getMillsInAnHour());
   }

   /**
      <P>How many days separate the provided dates?</P>

      @return  <CODE><A HREF="~JD~getXMinusYUnits(jud,jud,l)~EJD~">getXMinusYUnits</A>(d_x, d_y, <A HREF="#getMillsInADay()">getMillsInADay</A>())</CODE>
    **/
   public final int getXMinusYDays(Date d_x, Date d_y)  {
      return getXMinusYUnits(d_x, d_y, getMillsInADay());
   }

   /**
      <P>How many weeks separate the provided dates?</P>

      @return  <CODE><A HREF="~JD~getXMinusYUnits(jud,jud,l)~EJD~">getXMinusYUnits</A>(d_x, d_y, <A HREF="#getMillsInAWeek()">getMillsInAWeek</A>())</CODE>
    **/
   public final int getXMinusYWeeks(Date d_x, Date d_y)  {
      return getXMinusYUnits(d_x, d_y, getMillsInAWeek());
   }

   /**
      <P>How many units separate the provided dates?</P>

      @return  <CODE>(new <A HREF="~JD~L#L(l)~EJD~">Long</A>(d_x, d_y, l_multiplier)).<A HREF="~JD~L~EJD~#intValue()">intValue</A>()</CODE>
    **/
   public final int getXMinusYUnits(Date d_x, Date d_y, long l_multiplier)  {
      return (new Long(((d_x.getTime() - d_y.getTime()) / l_multiplier))).intValue();
   }

   /**
      <P>How many units, represented by a long, separate the provided dates?</P>

      @param  d_x  The date on the left side of the minus equation.  May not be null.
      @param  d_y  The date on the right side of the minus equation.  May not be null.
      @param  l_multiplier  The number used to translate a Date's milleseconds to some other unit.  May not be zero.

      @return  <CODE>(d_x.<A HREF="~JD~jud~EJD~#getTime()">getTime</A>() - d_y.getTime()) / l_multiplier)</CODE>
    **/
   public final long getXMinusYUnitsLong(Date d_x, Date d_y, long l_multiplier)  {
      throwAXIfNull(d_x, "d_x", "getXMinusYUnits");
      throwAXIfNull(d_y, "d_y", "getXMinusYUnits");
      if(l_multiplier == 0)  {
         throwAX("getXMinusYUnits:  l_multiplier is zero.");
      }

      return ((d_x.getTime() - d_y.getTime()) / l_multiplier);
   }

   /**
      <P>How many milleseconds are there in a second?</P>

      @return <B>1000</B>
    **/
   public static final long getMillsInASecond()  {
      return 1000;
   }

   /**
      <P>How many milleseconds are there in a minute?</P>

      @return <B>60000</B>  <I><A HREF="#getMillsInASecond()">getMillsInASecond</A> times sixty.</I>
    **/
   public static final long getMillsInAMinute()  {
      return 60000;
   }

   /**
      <P>How many milleseconds are there in an hour?</P>

      @return <B>360000</B>  <I><A HREF="#getMillsInAMinute()">getMillsInAMinute</A> times sixty</I>
    **/
   public static final long getMillsInAnHour()  {
      return 3600000;
   }

   /**
      <P>How many milleseconds are there in a day?</P>

      @return <B>8640000</B>  <I><A HREF="#getMillsInAnHour()">getMillsInAnHour</A> times twenty four</I>
    **/
   public static final long getMillsInADay()  {
      return 8640000;
   }

   /**
      <P>How many milleseconds are there in a week?</P>

      @return <B>60480000</B>  <I><A HREF="#getMillsInADay()">getMillsInADay</A> times seven</I>
    **/
   public static final long getMillsInAWeek()  {
      return 60480000;
   }
}