// Copyright (c) 2001 Hursh Jain (http://www.mollypages.org) 
// The Molly framework is freely distributable under the terms of an
// MIT-style license. For details, see the molly pages web site at:
// http://www.mollypages.org/. Use, modify, have fun !

package fc.util;

import java.util.*;

/** 
A range of dates.
<p>

@author hursh jain
**/
public class DateRange extends Range
{
Date start;
Date end;

/** 
Constructs a date range between the specified start and end 
dates (both inclusive).

@throws IllegalArgumentException 
    if the end date is lesser (via an <tt>compareTo</tt> 
    comparison) than the start date (equal to the start date 
    is ok)
**/
public DateRange(Date start, Date end) 
  {
  Argcheck.istrue(start.compareTo(end) <= 0, "end lesser than start in the specified range, start=["+start+"], end=["+end+"]");
  this.start = start;
  this.end = end;
  }

/** Get the start date for this range **/
public Date getStart() 
  {
  return start;
  }


/** Get the end date for this range **/
public Date getEnd() 
  {
  return end;
  }
  
/** 
@return true if the passed in date is inside this range. Note,
the <u>entire</u> date (including the milliseconds/seconds portion)
is considered by this function.

@throws IllegalArgumentException
    if the specified date was null
**/
public boolean inRange(Date d) 
  {
  Argcheck.notnull(d);
  boolean result = d.compareTo(start) >= 0 &&
           d.compareTo(end) <= 0;
  
  if (negated)
    return !result;
  else
    return result;
  }
 
 
/** 
@return true if any part of the passed in date range overlaps this range. Note,
the <u>entire</u> date (including the milliseconds/seconds portion) is considered by this function.

@throws IllegalArgumentException
    if the specified date was null
**/
public boolean overlaps(DateRange dr) 
  {
  Argcheck.notnull(dr);
  
  boolean result = inRange(dr.getStart()) || inRange(dr.getEnd());      
  if (negated)
    return !result;
  else
    return result;
  } 

 
/** 
Set the start date for this range 

@throws NullPointerException
    if the specified date was null
@throws IllegalArgumentException 
    if the specified date is greater (via an <tt>compareTo</tt> 
    comparison) than the currently set end date (equal to the 
    end date is ok)
**/
public void setStart(Date d) 
  {
  Argcheck.notnull(d, "specified argument was null");
  Argcheck.istrue(d.compareTo(end) <= 0, "start greater than end date, specified start=["+d+"], end=["+end+"]");
  start = d;
  }

/** 
Sets the end date for this range 

@param  d the end date

@throws NullPointerException
    if the specified date was null
@throws IllegalArgumentException 
        if the specified end date is lesser (via an <tt>compareTo</tt> 
    comparison) than the currently set start date (equal to 
    the start date is ok)
**/
public void setEnd(Date d) 
  {
  Argcheck.notnull(d, "specified argument was null");
  Argcheck.istrue(d.compareTo(start) >= 0, "end lesser than start, start=["+start+"], specified end=["+d+"]");
  end = d;
  }


/** Output a string representation of the date range **/
public java.lang.String toString() 
  {
  String str = "DateRange:[";
  if (isNegated())
    str += "^";
  str += start + "," + end + "]";
  return str;
  }

public static void main(String[] args)
  {
  Calendar cal = Calendar.getInstance();
  Date d1 = cal.getTime();
  
  //roll back 1 month
//  cal.set(Calendar.MONTH, false);
  cal.add(Calendar.MONTH, -1);
  Date d2 = cal.getTime();
     
  DateRange r = new DateRange(d2, d1);
  System.out.println("constructed range:" + r);
  //normal
  test(r);
  
  System.out.println();

  DateRange r2 = new DateRange(d2, new Date(d1.getTime() - CalendarUtil.ONE_DAY));
  System.out.println("r1:" + r + "\n    -- overlaps? --\n" + "r2:" + r2);
  System.out.println();
  System.out.println("r1 overlaps r2 (should be true): " + r.overlaps(r2));
  System.out.println("r2 overlaps r1 (should be true): " + r2.overlaps(r));

  System.out.println("----------------------------------");

  r2 = new DateRange(
    new Date(d1.getTime() + CalendarUtil.ONE_DAY),
    new Date(d1.getTime() + CalendarUtil.THREE_DAY));

  System.out.println("r1:" + r + "\n    -- overlaps? --\n" + "r2:" + r2);
  System.out.println();
  System.out.println("r1 overlaps r2 (should be false): " + r.overlaps(r2));
  System.out.println("r2 overlaps r1 (should be false): " + r2.overlaps(r));

  System.out.println("----------------------------------");

  r2 = new DateRange(
    new Date(d2.getTime() - CalendarUtil.THREE_DAY),
    new Date(d2.getTime() - CalendarUtil.ONE_DAY));

  System.out.println("r1:" + r + "\n    -- overlaps? --\n" + "r2:" + r2);
  System.out.println();
  System.out.println("r1 overlaps r2 (should be false): " + r.overlaps(r2));
  System.out.println("r2 overlaps r1 (should be false): " + r2.overlaps(r));

  System.out.println("----------------------------------");

  }

private static void test(DateRange r) 
  {
  Date d = new Date();

  System.out.println("in range: " + d + "=" + r.inRange(d));

  Calendar cal = Calendar.getInstance();
  cal.setTime(d);
  cal.add(Calendar.MONTH, -2);

  d = cal.getTime();
  System.out.println("in range: " + d + "=" + r.inRange(d));
  
  cal.add(Calendar.MONTH, 2);
  cal.roll(Calendar.DAY_OF_MONTH, false);
  d = cal.getTime();  
  System.out.println("in range: " + d + "=" + r.inRange(d));
  }

}          //~class CharRange