<?php
/* SVN FILE: $Id$ */

/**
 * Time Helper class file.
 *
 * PHP versions 4 and 5
 *
 * CakePHP(tm) :  Rapid Development Framework <http://www.cakephp.org/>
 * Copyright 2005-2007, Cake Software Foundation, Inc.
 *								1785 E. Sahara Avenue, Suite 490-204
 *								Las Vegas, Nevada 89104
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @filesource
 * @copyright		Copyright 2005-2007, Cake Software Foundation, Inc.
 * @link				http://www.cakefoundation.org/projects/info/cakephp CakePHP(tm) Project
 * @package			cake
 * @subpackage		cake.cake.libs.view.helpers
 * @since			CakePHP(tm) v 0.10.0.1076
 * @version			$Revision$
 * @modifiedby		$LastChangedBy$
 * @lastmodified	$Date$
 * @license			http://www.opensource.org/licenses/mit-license.php The MIT License
 */

/**
 * Time Helper class for easy use of time data.
 *
 * Manipulation of time data.
 *
 * @package		cake
 * @subpackage	cake.cake.libs.view.helpers
 */
class TimeHelper extends AppHelper {

/**
 * Returns given string trimmed to given length, adding an ending (default: "..") if necessary.
 *
 * @param string $string String to trim
 * @param integer $length Length of returned string, excluding ellipsis
 * @param string $ending Ending to be appended after trimmed string
 * @return string Trimmed string
 */
	function trim($string, $length, $ending = '..') {
		return substr($string, 0, $length) . (strlen($string) > $length ? $ending : null);
	}
/**
 * Returns a UNIX timestamp, given either a UNIX timestamp or a valid strtotime() date string.
 *
 * @param string $date_string Datetime string
 * @return string Formatted date string
 */
	function fromString($date_string) {
		if (is_integer($date_string) || is_numeric($date_string)) {
			return intval($date_string);
		} else {
			return strtotime($date_string);
		}
	}
/**
 * Returns a nicely formatted date string for given Datetime string.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return string Formatted date string
 */
	function nice($date_string = null) {
		if ($date_string != null) {
			$date = $this->fromString($date_string);
		} else {
			$date = time();
		}

		$ret = date("D, M jS Y, H:i", $date);
		return $this->output($ret);
	}
/**
 * Returns a formatted descriptive date string for given datetime string.
 *
 * If the given date is today, the returned string could be "Today, 16:54".
 * If the given date was yesterday, the returned string could be "Yesterday, 16:54".
 * If $date_string's year is the current year, the returned string does not
 * include mention of the year.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return string Described, relative date string
 */
	function niceShort($date_string = null) {
		$date = $date_string ? $this->fromString($date_string) : time();

		$y = $this->isThisYear($date) ? '' : ' Y';

		if ($this->isToday($date)) {
			$ret = "Today, " . date("H:i", $date);
		} elseif ($this->wasYesterday($date)) {
			$ret = "Yesterday, " . date("H:i", $date);
		} else {
			$ret = date("M jS{$y}, H:i", $date);
		}

		return $this->output($ret);
	}
/**
 * Returns a partial SQL string to search for all records between two dates.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @param string $end Datetime string or Unix timestamp
 * @param string $field_name Name of database field to compare with
 * @return string Partial SQL string.
 */
	function daysAsSql($begin, $end, $field_name) {
		$begin = $this->fromString($begin);
		$end = $this->fromString($end);
		$begin = date('Y-m-d', $begin) . ' 00:00:00';
		$end = date('Y-m-d', $end) . ' 23:59:59';

		$ret  ="($field_name >= '$begin') AND ($field_name <= '$end')";
		return $this->output($ret);
	}
/**
 * Returns a partial SQL string to search for all records between two times
 * occurring on the same day.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @param string $field_name Name of database field to compare with
 * @return string Partial SQL string.
 */
	function dayAsSql($date_string, $field_name) {
		$date = $this->fromString($date_string);
		$ret = $this->daysAsSql($date_string, $date_string, $field_name);
		return $this->output($ret);
	}
/**
 * Returns true if given datetime string is today.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return boolean True if datetime string is today
 */
	function isToday($date_string) {
		$date = $this->fromString($date_string);
		$ret = date('Y-m-d', $date) == date('Y-m-d', time());
		return $this->output($ret);
	}
/**
 * Returns true if given datetime string is within this week
 * @param string $date_string
 * @return boolean True if datetime string is within current week
 */
	function isThisWeek($date_string) {
		$date = $this->fromString($date_string) + 86400;
		return date('W Y', $date) == date('W Y', time());
	}
/**
 * Returns true if given datetime string is within this month
 * @param string $date_string
 * @return boolean True if datetime string is within current month
 */
	function isThisMonth($date_string) {
		$date = $this->fromString($date_string);
		return date('m Y',$date) == date('m Y', time());
	}
/**
 * Returns true if given datetime string is within current year.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return boolean True if datetime string is within current year
 */
	function isThisYear($date_string) {
		$date = $this->fromString($date_string);
		$ret = date('Y', $date) == date('Y', time());
		return $this->output($ret);
	}
/**
 * Returns true if given datetime string was yesterday.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return boolean True if datetime string was yesterday
 */
	function wasYesterday($date_string) {
		$date = $this->fromString($date_string);
		$ret = date('Y-m-d', $date) == date('Y-m-d', strtotime('yesterday'));
		return $this->output($ret);
	}
/**
 * Returns true if given datetime string is tomorrow.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return boolean True if datetime string was yesterday
 */
	function isTomorrow($date_string) {
		$date = $this->fromString($date_string);
		$ret = date('Y-m-d', $date) == date('Y-m-d', strtotime('tomorrow'));
		return $this->output($ret);
	}
/**
 * Returns a UNIX timestamp from a textual datetime description. Wrapper for PHP function strtotime().
 *
 * @param string $date_string Datetime string to be represented as a Unix timestamp
 * @return int Unix timestamp
 */
	function toUnix($date_string) {
		$ret = strtotime($date_string);
		return $this->output($ret);
	}
/**
 * Returns a date formatted for Atom RSS feeds.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return string Formatted date string
 */
	function toAtom($date_string) {
		$date = $this->fromString($date_string);
		$ret = date('Y-m-d\TH:i:s\Z', $date);
		return $this->output($ret);
	}
/**
 * Formats date for RSS feeds
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @return string Formatted date string
 */
	function toRSS($date_string) {
		$date = TimeHelper::fromString($date_string);
		$ret = date("r", $date);
		return $this->output($ret);
	}
/**
 * Returns either a relative date or a formatted date depending
 * on the difference between the current time and given datetime.
 * $datetime should be in a <i>strtotime</i>-parsable format, like MySQL's datetime datatype.
 *
 * Relative dates look something like this:
 *	3 weeks, 4 days ago
 *	15 seconds ago
 * Formatted dates look like this:
 *	on 02/18/2004
 *
 * The returned string includes 'ago' or 'on' and assumes you'll properly add a word
 * like 'Posted ' before the function output.
 *
 * @param string $date_string Datetime string or Unix timestamp
 * @param string $format Default format if timestamp is used in $date_string
 * @param string $backwards False if $date_string is in the past, true if in the future
 * @return string Relative time string.
 */
	function timeAgoInWords($datetime_string, $format = 'j/n/y', $backwards = false) {
		$datetime = $this->fromString($datetime_string);

		$in_seconds = $datetime;

		if ($backwards) {
			$diff = $in_seconds - time();
		} else {
			$diff = time() - $in_seconds;
		}

		$months = floor($diff / 2419200);
		$diff -= $months * 2419200;
		$weeks = floor($diff / 604800);
		$diff -= $weeks * 604800;
		$days = floor($diff / 86400);
		$diff -= $days * 86400;
		$hours = floor($diff / 3600);
		$diff -= $hours * 3600;
		$minutes = floor($diff / 60);
		$diff -= $minutes * 60;
		$seconds = $diff;

		if ($months > 0) {
			// over a month old, just show date (mm/dd/yyyy format)
			$relative_date = 'on ' . date($format, $in_seconds);
			$old = true;
		} else {
			$relative_date = '';
			$old = false;

			if ($weeks > 0) {
				// weeks and days
				$relative_date .= ($relative_date ? ', ' : '') . $weeks . ' week' . ($weeks > 1 ? 's' : '');
				$relative_date .= $days > 0 ? ($relative_date ? ', ' : '') . $days . ' day' . ($days > 1 ? 's' : '') : '';
			} elseif ($days > 0) {
				// days and hours
				$relative_date .= ($relative_date ? ', ' : '') . $days . ' day' . ($days > 1 ? 's' : '');
				$relative_date .= $hours > 0 ? ($relative_date ? ', ' : '') . $hours . ' hour' . ($hours > 1 ? 's' : '') : '';
			} elseif ($hours > 0) {
				// hours and minutes
				$relative_date .= ($relative_date ? ', ' : '') . $hours . ' hour' . ($hours > 1 ? 's' : '');
				$relative_date .= $minutes > 0 ? ($relative_date ? ', ' : '') . $minutes . ' minute' . ($minutes > 1 ? 's' : '') : '';
			} elseif ($minutes > 0) {
				// minutes only
				$relative_date .= ($relative_date ? ', ' : '') . $minutes . ' minute' . ($minutes > 1 ? 's' : '');
			} else {
				// seconds only
				$relative_date .= ($relative_date ? ', ' : '') . $seconds . ' second' . ($seconds != 1 ? 's' : '');
			}
		}

		$ret = $relative_date;
		// show relative date and add proper verbiage
		if (!$backwards && !$old) {
			$ret .= ' ago';
		}
		return $this->output($ret);
	}
/**
 * Alias for timeAgoInWords, but can also calculate dates in the future
 * @param string $date_string Datetime string or Unix timestamp
 * @param string $format Default format if timestamp is used in $date_string
 * @return string Relative time string.
 * @see		timeAgoInWords
 */
	function relativeTime($datetime_string, $format = 'j/n/y') {
		$date = strtotime($datetime_string);

		if (strtotime("now") > $date) {
			$ret = $this->timeAgoInWords($datetime_string, $format, false);
		} else {
			$ret = $this->timeAgoInWords($datetime_string, $format, true);
		}

		return $this->output($ret);
	}
/**
 * Returns true if specified datetime was within the interval specified, else false.
 *
 * @param mixed $timeInterval the numeric value with space then time type. Example of valid types: 6 hours, 2 days, 1 minute.
 * @param mixed $date_string the datestring or unix timestamp to compare
 * @return boolean
 */
	function wasWithinLast($timeInterval, $date_string) {
		$date = $this->fromString($date_string);
		$result = preg_split('/\\s/', $timeInterval);
		$numInterval = $result[0];
		$textInterval = $result[1];
		$currentTime = floor(time());
		$seconds = ($currentTime - floor($date));

		switch($textInterval) {
			case "seconds":
			case "second":
				$timePeriod = $seconds;
				$ret = $return;
			break;

			case "minutes":
			case "minute":
				$minutes = floor($seconds / 60);
				$timePeriod = $minutes;
			break;

			case "hours":
			case "hour":
				$hours = floor($seconds / 3600);
				$timePeriod = $hours;
			break;

			case "days":
			case "day":
				$days = floor($seconds / 86400);
				$timePeriod = $days;
			break;

			case "weeks":
			case "week":
				$weeks = floor($seconds / 604800);

				$timePeriod = $weeks;
			break;

			case "months":
			case "month":
				$months = floor($seconds / 2629743.83);
				$timePeriod = $months;
			break;

			case "years":
			case "year":
				$years = floor($seconds / 31556926);
				$timePeriod = $years;
			break;

			default:
				$days = floor($seconds / 86400);
				$timePeriod = $days;
			break;
		}

		if ($timePeriod <= $numInterval) {
			$ret = true;
		} else {
			$ret = false;
		}

		return $this->output($ret);
	}

	function gmt($string = null) {
		if ($string != null) {
			$string = $this->fromString($string);
		} else {
			$string = time();
		}
		$string = $this->fromString($string);
		$hour = intval(date("G", $string));
		$minute = intval(date("i", $string));
		$second = intval(date("s", $string));
		$month = intval(date("n", $string));
		$day = intval(date("j", $string));
		$year = intval(date("Y", $string));

		$return = gmmktime($hour, $minute, $second, $month, $day, $year);
		return $return;
	}
	
	function format($format = 'd-m-Y', $date) {
		return date($format, $this->fromString($date));
	}
}

?>