/*---------------------------------------------------------------------*\
|    Date class - properties & methods for dealing with date values	|
\*---------------------------------------------------------------------*/

define("TEXTDATE",2);		// for text (Mmmmmmmmmm dd, yyyy)
define("LONGDATE",1);		// long result (yyyy-mm-dd hh:mm:ss)
define("SHORTDATE",0);		// short result (yyyy-mm-dd)
define("VERYSHORTDATE",-1);	// very short date (mm/dd/yy)
define("ONEDAY",86400);		// one day's seconds

class Date {

	static $months = array	('January','February','March','April','May','June','July',
				 'August','September','October','November','December');
	static $javascript = 0;	// toggle for javascript date handler

	public $date;	// getdate array

/*
 *::Compare two Date objects:
 *	P1 = first Date object
 *	P2 = second Date object
 *	returns -1, 0, or 1 (<,=,>)
 */
static function compare($first,$second) {
	if ($first->date[0] == $second->date[0]) return 0;
	return ($first->date[0] < $second->date[0]) ? -1 : 1; 
	}
/*
 *::Obtain the +/-days difference between two Date objects:
 *	P1 = first Date object
 *	P2 = second Date object
 *	returns the (signed) difference in days
 */
static function difference($first,$second) {
	$days = ($first->date[0]-$second->date[0])/ONEDAY;
	return $days;
	}
/*
 *::Convert any date to an internal date
 *	P1 = date value as string--i.e. mm/dd/yyyy, etc.
 *	P2 = format: LONGDATE,SHORTDATE or VERYSHORTDATE
 *	returns an internal date in the requested format
 */
static function toInternal($date=null,$format=SHORTDATE) {
	$obj = $date ? new Date($date) : new Date;
	return $obj->internal($format);
	}
/*
 *::Convert any date to an external date
 *	P1 = date value as string--i.e. mm/dd/yyyy, etc.
 *	P2 = format: LONGDATE,SHORTDATE or VERYSHORTDATE
 *	returns an external date in the requested format
 */
static function toExternal($date=null,$format=SHORTDATE) {
	$obj = $date ? new Date($date) : new Date;
	return $obj->external($format);
	}
/*
 * Constructor:
 *	P1 = (optional) date value
 */
public function __construct($value=null) {
	if (!func_num_args())
		$this->date = getdate();
	else
		$this->set($value);
	}
/*
 * Destructor:
 */
public function __destruct() {}
/*
 * Determine if this object contains a valid date:
 *	returns true (valid) or false (invalid)
 */
public function valid() {
	return ($this->date ? true : false);
	}
/*
 * Set the date value for this object:
 *	P1 = (optional) date value, default = now()
 */
public function set($value=null) {
	if (! $value) {
		$this->date = null;
		return;
		}
	$this->date = getdate();
	while ($value) {
		// MySql timestamp:
		if (preg_match('/^\s*(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})\s*$/',$value,$parts)) {
			$this->date['year'] = 0+$parts[1];
			$this->date['mon'] = 0+$parts[2];
			$this->date['mday'] = 0+$parts[3];
			$this->date['hours'] = 0+$parts[4];
			$this->date['minutes'] = 0+$parts[5];
			$this->date['seconds'] = 0+$parts[6];
			break;
			}
		// Unix timestamp:
		if (preg_match('/^\s*([-]?\d{6,})\s*$/',$value,$parts)) {
			$this->date = getdate(0+$parts[1]);
			return;
			}
		// MySql internal date and time format:
		if (preg_match('/^(\d{4})-(\d{2})-(\d{2})\s+(\d{2}):(\d{2}):(\d{2})$/',$value,$parts)) {
			$this->date['year'] = 0+$parts[1];
			$this->date['mon'] = 0+$parts[2];
			$this->date['mday'] = 0+$parts[3];
			$this->date['hours'] = 0+$parts[4];
			$this->date['minutes'] = 0+$parts[5];
			$this->date['seconds'] = 0+$parts[6];
			break;
			}
		// MySql internal date format:
		if (preg_match('/^(\d{4})-(\d{2})-(\d{2})$/',$value,$parts)) {
			$this->date['year'] = 0+$parts[1];
			$this->date['mon'] = 0+$parts[2];
			$this->date['mday'] = 0+$parts[3];
			$this->date['hours'] = $this->date['minutes'] = $this->date['seconds'] = 0;
			break;
			}
		// only hour specified:
		if (preg_match('/^\s*(\d{1,2})\s*$/',$value,$parts)) {
			$this->date['hours'] = 0+$parts[1];
			$this->date['minutes'] = $this->date['seconds'] = 0;
			break;
			}
		// only hour and meridian) specified:
		if (preg_match('/^\s*(\d{1,2})\s*([AaPp]{1}).*$/',$value,$parts)) {
			$this->date['hours'] = 0+$parts[1];
			$this->date['minutes'] = $this->date['seconds'] = 0;
			$meridian = strtolower($parts[2]);
			if ($meridian=='a' && $this->date['hours']==12)	$this->date['hours'] = 0; else
			 if ($meridian=='p' && $this->date['hours']<12)	$this->date['hours'] += 12;
			break;
			}
		// only hour and minutes (and maybe meridian) specified:
		if (preg_match('/^\s*(\d{1,2}):(\d{1,2})\s*([AaPp]?).*$/',$value,$parts)) {
			$this->date['hours'] = 0+$parts[1];
			$this->date['minutes'] = 0+$parts[2];
			$this->date['seconds'] = 0;
			$meridian = strtolower($parts[3]);
			if ($meridian=='a' && $this->date['hours']==12)	$this->date['hours'] = 0; else
			 if ($meridian=='p' && $this->date['hours']<12)	$this->date['hours'] += 12;
			break;
			}
		// only hours, minutes and seconds (and maybe meridian) specified:
		if (preg_match('/^\s*(\d{1,2}):(\d{1,2}):(\d{1,2})\s*([AaPp]?).*$/',$value,$parts)) {
			$this->date['hours'] = 0+$parts[1];
			$this->date['minutes'] = 0+$parts[2];
			$this->date['seconds'] = 0+$parts[3];
			$meridian = strtolower($parts[4]);
			if ($meridian=='a' && $this->date['hours']==12)	$this->date['hours'] = 0; else
			 if ($meridian=='p' && $this->date['hours']<12)	$this->date['hours'] += 12;
			break;
			}
		$this->date['hours'] = $this->date['minutes'] = $this->date['seconds'] = 0;
		// look for m/d/y:
		if (preg_match('/^(\d{1,2})[\/\-\.](\d{1,2})[\/\-\.](\d{1,4})/',$value,$parts)) {
			if ($parts[3] < 100)
				if ($parts[3] < 50)	$parts[3] += 2000;
					else		$parts[3] += 1900;
			$this->date['mon'] = 0+$parts[1];
			$this->date['mday'] = 0+$parts[2];
			$this->date['year'] = 0+$parts[3];
			}
		else
		// look for m/d:
		if (preg_match('/^(\d{1,2})[\/\-\.](\d{1,2})/',$value,$parts)) {
			$this->date['mon'] = 0+$parts[1];
			$this->date['mday'] = 0+$parts[2];
			}
		// look for hh:mm:ss
		if (preg_match('/(\d{1,2}):(\d{1,2}):(\d{1,2})/',$value,$parts)) {
			$this->date['hours'] = 0+$parts[1];
			$this->date['minutes'] = 0+$parts[2];
			$this->date['seconds'] = 0+$parts[3];
			}
		else
		// look for hh:mm
		if (preg_match('/(\d{1,2}):(\d{1,2})/',$value,$parts)) {
			$this->date['hours'] = 0+$parts[1];
			$this->date['minutes'] = 0+$parts[2];
			}
		else
		if (preg_match('/(\d{1,2})[AaPp]/',$value,$parts))
			$this->date['hours'] = 0+$parts[1];
		if (preg_match('/[Aa]/',$value) && ($this->date['hours'] == 12))
			$this->date['hours'] = 00;
		else
		if (preg_match('/[Pp]/',$value) && ($this->date['hours'] < 12))
			$this->date['hours'] += 12;
		break;
		}
	$this->date[0] = mktime(
		$this->date['hours'],
		$this->date['minutes'],
		$this->date['seconds'],
		$this->date['mon'],
		$this->date['mday'],
		$this->date['year']
		);
	$this->date = getdate($this->date[0]);
	}
/*
 * Return an internal (SQL) date for this object:
 *	P1 = (optional) toggle, long or short result
 *	returns a string as: yyyy-mm-dd( hh:mm:ss)
 */
public function internal($size=SHORTDATE) {
	if (! $this->valid()) return null;
	$result = sprintf("%04d-%02d-%02d",
			  $this->date['year'],$this->date['mon'],$this->date['mday']);
	if ($size!=SHORTDATE)
		$result .= sprintf(" %02d:%02d:%02d",$this->date['hours'],
				   $this->date['minutes'],$this->date['seconds']);
	return $result;
	}
/*
 * Return an external date for this object:
 *	P1 = (optional) toggle: text, long, short or very short result
 *	returns a string as: mm/dd/(yy)yy( hh:mm:ss a|pm) or Mmmmmmmm dd, yyyy
 */
public function external($size=SHORTDATE) {
	if (! $this->valid()) return null;
	$result = sprintf("%d/%d/%04d",$this->date['mon'],$this->date['mday'],$this->date['year']);
	if ($size==VERYSHORTDATE) {
		$year = $this->date['year'] - (($this->date['year'] < 2000) ? 1900 : 2000);
		return sprintf("%d/%d/%02d",$this->date['mon'],$this->date['mday'],$year);
		}
	if ($size==TEXTDATE) {
		return sprintf(
			"%s %d, %04d",
			self::$months[$this->date['mon']-1],
			$this->date['mday'],
			$this->date['year']
			);
		}
	if ($size==LONGDATE) {
		$hour = $this->date['hours'];
		$mer = "am";
		if ($hour < 12) {
			$mer = "am";
			if ($hour == 0) $hour = 12;
			}
		else	{
			$mer = "pm";
			if ($hour > 12) $hour -= 12;
			}
		$result .= sprintf(" %d:%02d %s",$hour,$this->date['minutes'],$mer);
		}
	return $result;
	}
/*
 * Move the object's date by various intervals:
 *	P1 = interval to move the date, i.e.
 *		"(-)nn second(s)"
 *		"(-)nn minute(s)"
 *		"(-)nn hour(s)"
 *		"(-)nn day(s)"
 *		"(-)nn weekday(s)"
 *		"(-)nn week(s)"
 *		"(-)nn month(s)"
 *		"(-)nn quarter(s)"
 *		"(-)nn year(s)"
 *	returns internal value for new date
 */
public function move($interval=null) {
	if (! $this->valid()) return null;
	preg_match('/([0-9-]+)\s*([a-zA-Z]+)*/',$interval,$parts);
	$reps = 0+$parts[1]; $step = strtolower($parts[2]);
	if (! $reps) return $this->internal(LONGDATE);
	if (preg_match('/weekday/',$step)) {
		$count = abs($reps);
		$cursor = ($reps < 0) ? -1 : 1;
		while ($count--)
			while (1) {
				$this->date = getdate(mktime(
					$this->date['hours'],
					$this->date['minutes'],
					$this->date['seconds'],
					$this->date['mon'],
					($this->date['mday']+$cursor),
					$this->date['year']
					));
				if (($this->date['wday']>0) && ($this->date['wday']<6)) break;
				}
		return $this->internal(LONGDATE);
		}
	switch ($step) {
		case "hour": case "hours":
			$this->date['hours'] += $reps;
			break;
		case "minute": case "minutes":
			$this->date['minutes'] += $reps;
			break;
		case "second": case "seconds":
			$this->date['seconds'] += $reps;
			break;
		case "week": case "weeks":
			$this->date['mday'] += ($reps * 7);
			break;
		case "month": case "months":
			$this->date['mon'] += $reps;
			break;
		case "quarter": case "quarters":
			$this->date['mon'] += ($reps * 3);
			break;
		case "year": case "years":
			$this->date['year'] += $reps;
			break;
		case "day": case "days":
		default:
			$this->date['mday'] += $reps;
			break;
		}
	$this->date = getdate(mktime(
		$this->date['hours'],
		$this->date['minutes'],
		$this->date['seconds'],
		$this->date['mon'],
		$this->date['mday'],
		$this->date['year']
		));
	return $this->internal(LONGDATE);
	}
/*
 * Return the html for selecting the date(& time) starting with object value:
 *	P1 = name of the html object/form result
 *	P2 = (optional) length of the returned value (SHORTDATE or LONGDATE)
 *	P3 = (optional) css class for the fields
 *	returns html string for the form fields
 */
public function select($name,$size=SHORTDATE,$class=null) {
	$html = "";
	if (! self::$javascript++) $html = <<<ETX
<script language="JavaScript" type="text/javascript">
// Build date(&time) field from parts
// call w/ID of date field
function buildDate(id) {
var e=document.getElementById(id),n=e.name,f=e.form;
if (	eval('f.'+n+'_yr.selectedIndex==0') ||
	eval('f.'+n+'_mo.selectedIndex==0') ||
	eval('f.'+n+'_dy.selectedIndex==0')) {
	e.value='';
	return;
	}
var yr=Number(eval('f.'+n+'_yr.options[f.'+n+'_yr.selectedIndex].value'));
var mo=Number(eval('f.'+n+'_mo.options[f.'+n+'_mo.selectedIndex].value'));
var dy=Number(eval('f.'+n+'_dy.options[f.'+n+'_dy.selectedIndex].value'));
yr=yr.toString(); mo=mo.toString(); if (mo.length<2) mo='0'+mo;
dy=dy.toString(); if (dy.length<2) dy='0'+dy;
e.value=yr+'-'+mo+'-'+dy;
if (eval('typeof f.'+n+'_hh')=='undefined') return; // no time
if (eval('f.'+n+'_hh.selectedIndex==0')) return;
if (eval('f.'+n+'_mm.selectedIndex')==0) eval('f.'+n+'_mm.selectedIndex=1');
var hh=Number(eval('f.'+n+'_hh.options[f.'+n+'_hh.selectedIndex].value'));
var mm=Number(eval('f.'+n+'_mm.options[f.'+n+'_mm.selectedIndex].value'));
var ss=0;
var mer=eval('f.'+n+'_mer.options[f.'+n+'_mer.selectedIndex].value');
if (hh==12) hh=0; if (mer=='pm') hh+=12;
hh=hh.toString(); if (hh.length<2) hh='0'+hh;
mm=mm.toString(); if (mm.length<2) mm='0'+mm;
ss=ss.toString(); if (ss.length<2) ss='0'+ss;
e.value=e.value+' '+hh+':'+mm+':'+ss;
}
</script>
ETX;

	$two = "%02d"; $four = "%04d";
	$css = $class ? " class=\"{$class}\"" : null;
	$mo = $this->date['mon']; $dy = $this->date['mday']; $yr = $this->date['year'];
	$hh = $this->date['hours']; $mm = $this->date['minutes'];
	$mer = "am";
	if ($this->valid()) {
		if ($hh >= 12) {
			$mer = "pm";
			if ($hh > 12) $hh -= 12;
			}
		if (! $hh) $hh = 12;
		}
	$default = $this->internal($size);
	if ($size && $default) $default = substr($default,0,-2) . "00";
	$html .= "<input id=\"{$name}\" type=\"hidden\" name=\"{$name}\" value=\"{$default}\">\n";
	$html .= "<select name=\"{$name}_mo\" size=\"1\" onChange=\"buildDate('{$name}')\"{$css}>";
	$html .= $this->date ? "<option></option>" : "<option selected></option>";
	for ($ix=1; $ix<=12; ++$ix) {
		$selected = ($mo == $ix) ? " selected" : null;
		$text = self::$months[$ix-1];
		$html .= "<option value=\"{$ix}\"{$selected}>{$text}</option>";
		}
	$html .= "</select>";
	$html .= "<select name=\"{$name}_dy\" size=\"1\" onChange=\"buildDate('{$name}')\"{$css}>";
	$html .= $this->date ? "<option></option>" : "<option selected></option>";
	for ($ix=1; $ix<=31; ++$ix) {
		$selected = ($dy == $ix) ? " selected" : null;
		$text = $ix;
		$html .= "<option value=\"{$ix}\"{$selected}>{$text}</option>";
		}
	$html .= "</select>";
	$html .= "<select name=\"{$name}_yr\" size=\"1\" onChange=\"buildDate('{$name}')\"{$css}>";
	$html .= $this->date ? "<option></option>" : "<option selected></option>";
	$now = date("Y") + 13;
	for ($ix=$now; $ix>1949; --$ix) {
		$selected = ($yr == $ix) ? " selected" : null;
		$text = $ix;
		$html .= "<option value=\"{$ix}\"{$selected}>{$text}</option>";
		}
	$html .= "</select>\n";
	if (! $size) return $html;
	$html .= "<select name=\"{$name}_hh\" size=\"1\" onChange=\"buildDate('{$name}')\"{$css}>";
	$html .= $this->date ? "<option></option>" : "<option selected></option>";
	for ($ix=1; $ix<=12; ++$ix) {
		$selected = ($this->date && ($hh == $ix)) ? " selected" : null;
		$text = sprintf($two,$ix);
		$html .= "<option value=\"{$ix}\"{$selected}>{$text}</option>";
		}
	$html .= "</select>";
	$html .= "<select name=\"{$name}_mm\" size=\"1\" onChange=\"buildDate('{$name}')\"{$css}>";
	$html .= $this->date ? "<option></option>" : "<option selected></option>";
	for ($ix=0; $ix<=59; ++$ix) {
		$selected = (($mm !== null) && ($mm == $ix)) ? " selected" : null;
		$text = sprintf($two,$ix);
		$html .= "<option value=\"{$ix}\"{$selected}>{$text}</option>";
		}
	$html .= "</select>";
	$html .= "<select name=\"{$name}_mer\" size=\"1\" onChange=\"buildDate('{$name}')\"{$css}>";
	foreach (array('am','pm') as $ix) {
		$selected = ($mer == $ix) ? " selected" : null;
		$text = $ix;
		$html .= "<option value=\"{$ix}\"{$selected}>{$text}</option>";
		}
	$html .= "</select>\n";
	return $html;
	}

}