<?php /* $Id: cron_class.php,v 1.1 2008-06-17 05:39:22 e107coders Exp $ */

/**####################################################################################################**\
   Version: V1.01
   Release Date: 12 Sep 2005
   Licence: GPL
   By: Nikol S
   Please send bug reports to ns@eyo.com.au
\**####################################################################################################**/

/* This class is based on the concept in the CronParser class written by Mick Sear http://www.ecreate.co.uk
 * The following functions are direct copies from or based on the original class:
 * getLastRan(), getDebug(), debug(), expand_ranges()
 *
 * Who can use this class?
 * This class is idea for people who can not use the traditional Unix cron through shell.
 * One way of using is embedding the calling script in a web page which is often visited.
 * The script will work out the last due time, by comparing with run log timestamp. The scrip
 * will envoke any scripts needed to run, be it deleting older table records, or updating prices.
 * It can parse the same cron string used by Unix.
 */

/* Usage example:

$cron_str0 = "0,12,30-51 3,21-23,10 1-25 9-12,1 0,3-7";
require_once("CronParser.php");
$cron = new CronParser();
$cron->calcLastRan($cron_str0);
// $cron->getLastRanUnix() returns an Unix timestamp
echo "Cron '$cron_str0' last due at: " . date('r', $cron->getLastRanUnix()) . "<p>";
// $cron->getLastRan() returns last due time in an array
print_r($cron->getLastRan());
echo "Debug:<br>" . nl2br($cron->getDebug());

$cron_str1 = "3 12 * * *";
if ($cron->calcLastRan($cron_str1))
{
   echo "<p>Cron '$cron_str1' last due at: " . date('r', $cron->getLastRanUnix()) . "<p>";
   print_r($cron->getLastRan());
}
else
{
   echo "Error parsing";
}
echo "Debug:<br>" . nl2br($cron->getDebug());

 *#######################################################################################################
 */

class CronParser
{

 	var $bits = Array(); //exploded String like 0 1 * * *
 	var $now = Array();	//Array of cron-style entries for time()
 	var $lastRan; 		//Timestamp of last ran time.
 	var $taken;
 	var $debug;
	var $year;
	var $month;
	var $day;
	var $hour;
	var $minute;
	var $minutes_arr = array();	//minutes array based on cron string
	var $hours_arr = array();	//hours array based on cron string
	var $months_arr = array();	//months array based on cron string

	function getLastRan()
	{
		return explode(",", strftime("%M,%H,%d,%m,%w,%Y", $this->lastRan)); //Get the values for now in a format we can use
	}

	function getLastRanUnix()
	{
		return $this->lastRan;
	}

	function getDebug()
	{
 		return $this->debug;
	}

	function debug($str)
	{
		if (is_array($str))
		{
			$this->debug .= "\nArray: ";
			foreach($str as $k=>$v)
			{
				$this->debug .= "$k=>$v, ";
			}

		}
		else
		{
			$this->debug .= "\n$str";
		}
		//echo nl2br($this->debug);
	}

	/**
	 * Assumes that value is not *, and creates an array of valid numbers that
	 * the string represents.  Returns an array.
	 */
	function expand_ranges($str)
	{
		if (strstr($str,  ","))
		{
			$arParts = explode(',', $str);
			foreach ($arParts AS $part)
			{
				if (strstr($part, '-'))
				{
					$arRange = explode('-', $part);
					for ($i = $arRange[0]; $i <= $arRange[1]; $i++)
					{
						$ret[] = $i;
					}
				}
				else
				{
					$ret[] = $part;
				}
			}
		}
		elseif (strstr($str,  '-'))
		{
			$arRange = explode('-', $str);
			for ($i = $arRange[0]; $i <= $arRange[1]; $i++)
			{
				$ret[] = $i;
			}
		}
		else
		{
			$ret[] = $str;
		}
		$ret = array_unique($ret);
		sort($ret);
		return $ret;
	}

	function daysinmonth($month, $year)
	{
		return date('t', mktime(0, 0, 0, $month, 1, $year));
	}

	/**
	 *  Calculate the last due time before this moment
	 */
	function calcLastRan($string)
	{

 		$tstart = microtime();
		$this->debug = "";
		$this->lastRan = 0;
		$this->year = NULL;
		$this->month = NULL;
		$this->day = NULL;
		$this->hour = NULL;
		$this->minute = NULL;
		$this->hours_arr = array();
		$this->minutes_arr = array();
		$this->months_arr = array();

		$string = preg_replace('/[\s]{2,}/', ' ', $string);

		if (preg_match('/[^-,* \\d]/', $string) !== 0)
		{
			$this->debug("Cron String contains invalid character");
			return false;
		}

		$this->debug("<b>Working on cron schedule: $string</b>");
 		$this->bits = @explode(" ", $string);

		if (count($this->bits) != 5)
		{
			$this->debug("Cron string is invalid. Too many or too little sections after explode");
			return false;
		}

		//put the current time into an array
		$t = strftime("%M,%H,%d,%m,%w,%Y", time());
		$this->now = explode(",", $t);

		$this->year = $this->now[5];

		$arMonths = $this->_getMonthsArray();

		do
		{
			$this->month = array_pop($arMonths);
		}
		while ($this->month > $this->now[3]);

		if ($this->month === NULL)
		{
			$this->year = $this->year - 1;
			$this->debug("Not due within this year. So checking the previous year " . $this->year);
			$arMonths = $this->_getMonthsArray();
			$this->_prevMonth($arMonths);
		}
		elseif ($this->month == $this->now[3]) //now Sep, month = array(7,9,12)
		{
			$this->debug("Cron is due this month, getting days array.");
			$arDays = $this->_getDaysArray($this->month, $this->year);

			do
			{
				$this->day = array_pop($arDays);
			}
			while ($this->day > $this->now[2]);

			if ($this->day === NULL)
			{
				$this->debug("Smallest day is even greater than today");
				$this->_prevMonth($arMonths);
			}
			elseif ($this->day == $this->now[2])
			{
				$this->debug("Due to run today");
				$arHours = $this->_getHoursArray();

				do
				{
					$this->hour = array_pop($arHours);
				}
				while ($this->hour > $this->now[1]);

				if ($this->hour === NULL) // now =2, arHours = array(3,5,7)
				{
					$this->debug("Not due this hour and some earlier hours, so go for previous day");
					$this->_prevDay($arDays, $arMonths);
				}
				elseif ($this->hour < $this->now[1]) //now =2, arHours = array(1,3,5)
				{
					$this->minute = $this->_getLastMinute();
				}
				else // now =2, arHours = array(1,2,5)
				{
					$this->debug("Due this hour");
					$arMinutes = $this->_getMinutesArray();
					do
					{
						$this->minute = array_pop($arMinutes);
					}
					while ($this->minute > $this->now[0]);

					if ($this->minute === NULL)
					{
						$this->debug("Not due this minute, so go for previous hour.");
						$this->_prevHour($arHours, $arDays, $arMonths);
					}
					else
					{
						$this->debug("Due this very minute or some earlier minutes before this moment within this hour.");
					}
				}
			}
			else
			{
				$this->debug("Cron was due on " . $this->day . " of this month");
				$this->hour = $this->_getLastHour();
				$this->minute = $this->_getLastMinute();
			}
		}
		else //now Sep, arrMonths=array(7, 10)
		{
			$this->debug("Cron was due before this month. Previous month is: " . $this->year . '-' . $this->month);
			$this->day = $this->_getLastDay($this->month, $this->year);
			if ($this->day === NULL)
			{
				//No scheduled date within this month. So we will try the previous month in the month array
				$this->_prevMonth($arMonths);
			}
			else
			{
				$this->hour = $this->_getLastHour();
				$this->minute = $this->_getLastMinute();
			}
		}

		$tend = microtime();
		$this->taken = $tend - $tstart;
		$this->debug("Parsing $string taken " . $this->taken . " seconds");

		//if the last due is beyond 1970
		if ($this->minute === NULL)
		{
			$this->debug("Error calculating last due time");
			return false;
		}
		else
		{
			$this->debug("LAST DUE: " . $this->hour . ":" . $this->minute . " on " . $this->day . "/" . $this->month . "/" . $this->year);
			$this->lastRan = mktime($this->hour, $this->minute, 0, $this->month, $this->day, $this->year);
			return true;
		}
	}

	//get the due time before current month
	function _prevMonth($arMonths)
	{
		$this->month = array_pop($arMonths);
		if ($this->month === NULL)
		{
			$this->year = $this->year -1;
			if ($this->year <= 1970)
			{
				$this->debug("Can not calculate last due time. At least not before 1970..");
			}
			else
			{
				$this->debug("Have to go for previous year " . $this->year);
				$arMonths = $this->_getMonthsArray();
				$this->_prevMonth($arMonths);
			}
		}
		else
		{
			$this->debug("Getting the last day for previous month: " . $this->year . '-' . $this->month);
			$this->day = $this->_getLastDay($this->month, $this->year);

			if ($this->day === NULL)
			{
				//no available date schedule in this month
				$this->_prevMonth($arMonths);
			}
			else
			{
				$this->hour = $this->_getLastHour();
				$this->minute = $this->_getLastMinute();
			}
		}

	}

	//get the due time before current day
	function _prevDay($arDays, $arMonths)
	{
		$this->debug("Go for the previous day");
		$this->day = array_pop($arDays);
		if ($this->day === NULL)
		{
			$this->debug("Have to go for previous month");
			$this->_prevMonth($arMonths);
		}
		else
		{
			$this->hour = $this->_getLastHour();
			$this->minute = $this->_getLastMinute();
		}
	}

	//get the due time before current hour
	function _prevHour($arHours, $arDays, $arMonths)
	{
		$this->debug("Going for previous hour");
		$this->hour = array_pop($arHours);
		if ($this->hour === NULL)
		{
			$this->debug("Have to go for previous day");
			$this->_prevDay($arDays, $arMonths);
		}
		else
		{
			$this->minute = $this->_getLastMinute();
		}
	}

	//not used at the moment
	function _getLastMonth()
	{
		$months = $this->_getMonthsArray();
		$month = array_pop($months);

		return $month;
	}

	function _getLastDay($month, $year)
	{
		//put the available days for that month into an array
		$days = $this->_getDaysArray($month, $year);
		$day = array_pop($days);

		return $day;
	}

	function _getLastHour()
	{
		$hours = $this->_getHoursArray();
		$hour = array_pop($hours);

		return $hour;
	}

	function _getLastMinute()
	{
		$minutes = $this->_getMinutesArray();
		$minute = array_pop($minutes);

		return $minute;
	}

	//remove the out of range array elements. $arr should be sorted already and does not contain duplicates
	function _sanitize ($arr, $low, $high)
	{
		$count = count($arr);
		for ($i = 0; $i <= ($count - 1); $i++)
		{
			if ($arr[$i] < $low)
			{
				$this->debug("Remove out of range element. {$arr[$i]} is outside $low - $high");
				unset($arr[$i]);
			}
			else
			{
				break;
			}
		}

		for ($i = ($count - 1); $i >= 0; $i--)
		{
			if ($arr[$i] > $high)
			{
				$this->debug("Remove out of range element. {$arr[$i]} is outside $low - $high");
				unset ($arr[$i]);
			}
			else
			{
				break;
			}
		}

		//re-assign keys
		sort($arr);
		return $arr;
	}

	//given a month/year, list all the days within that month fell into the week days list.
	function _getDaysArray($month, $year = 0)
	{
		if ($year == 0)
		{
			$year = $this->year;
		}

		$days = array();

		//return everyday of the month if both bit[2] and bit[4] are '*'
		if ($this->bits[2] == '*' AND $this->bits[4] == '*')
		{
			$days = $this->getDays($month, $year);
		}
		else
		{
			//create an array for the weekdays
			if ($this->bits[4] == '*')
			{
				for ($i = 0; $i <= 6; $i++)
				{
					$arWeekdays[] = $i;
				}
			}
			else
			{
				$arWeekdays = $this->expand_ranges($this->bits[4]);
				$arWeekdays = $this->_sanitize($arWeekdays, 0, 7);

				//map 7 to 0, both represents Sunday. Array is sorted already!
				if (in_array(7, $arWeekdays))
				{
					if (in_array(0, $arWeekdays))
					{
						array_pop($arWeekdays);
					}
					else
					{
						$tmp[] = 0;
						array_pop($arWeekdays);
						$arWeekdays = array_merge($tmp, $arWeekdays);
					}
				}
			}
			$this->debug("Array for the weekdays");
			$this->debug($arWeekdays);

			if ($this->bits[2] == '*')
			{
				$daysmonth = $this->getDays($month, $year);
			}
			else
			{
				$daysmonth = $this->expand_ranges($this->bits[2]);
				// so that we do not end up with 31 of Feb
				$daysinmonth = $this->daysinmonth($month, $year);
				$daysmonth = $this->_sanitize($daysmonth, 1, $daysinmonth);
			}

			//Now match these days with weekdays
			foreach ($daysmonth AS $day)
			{
				$wkday = date('w', mktime(0, 0, 0, $month, $day, $year));
				if (in_array($wkday, $arWeekdays))
				{
					$days[] = $day;
				}
			}
		}
		$this->debug("Days array matching weekdays for $year-$month");
		$this->debug($days);
		return $days;
	}

	//given a month/year, return an array containing all the days in that month
	function getDays($month, $year)
	{
		$daysinmonth = $this->daysinmonth($month, $year);
		$this->debug("Number of days in $year-$month : $daysinmonth");
		$days = array();
		for ($i = 1; $i <= $daysinmonth; $i++)
		{
			$days[] = $i;
		}
		return $days;
	}

	function _getHoursArray()
	{
		if (empty($this->hours_arr))
		{
			$hours = array();

			if ($this->bits[1] == '*')
			{
				for ($i = 0; $i <= 23; $i++)
				{
					$hours[] = $i;
				}
			}
			else
			{
				$hours = $this->expand_ranges($this->bits[1]);
				$hours = $this->_sanitize($hours, 0, 23);
			}

			$this->debug("Hour array");
			$this->debug($hours);
			$this->hours_arr = $hours;
		}
		return $this->hours_arr;
	}

	function _getMinutesArray()
	{
		if (empty($this->minutes_arr))
		{
			$minutes = array();

			if ($this->bits[0] == '*')
			{
				for ($i = 0; $i <= 60; $i++)
				{
					$minutes[] = $i;
				}
			}
			else
			{
				$minutes = $this->expand_ranges($this->bits[0]);
				$minutes = $this->_sanitize($minutes, 0, 59);
			}
			$this->debug("Minutes array");
			$this->debug($minutes);
			$this->minutes_arr = $minutes;
		}
		return $this->minutes_arr;
	}

	function _getMonthsArray()
	{
		if (empty($this->months_arr))
		{
			$months = array();
			if ($this->bits[3] == '*')
			{
				for ($i = 1; $i <= 12; $i++)
				{
					$months[] = $i;
				}
			}
			else
			{
				$months = $this->expand_ranges($this->bits[3]);
				$months = $this->_sanitize($months, 1, 12);
			}
			$this->debug("Months array");
			$this->debug($months);
			$this->months_arr = $months;
		}
		return $this->months_arr;
	}

}
?>