DateRange

dateRange

<?php

// Make sure direct access is not allowed
if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
 * Allows you to calculate the remainder of time from now to a given DateTime
 * 
 * @author   	Thomas Maurstad Larsson, Logoz As <thomas@logoz.no>
 * @link		http://nybilguiden.no
 * @copyright	Copyright (c) 2012
 */

class DateTimeDifference
{
	/** @var array 	Translation of difference between singular and plural in Norwegian */
	public static $translation = array
	(
		"day" => array("dag", "dager"),
		"hrs" => array("time", "timer"),
		"min" => array("minutt", "minutter"),
		"sec" => array("sekund", "sekunder"),
		"exp" => "Utgått",
	);
	
	private static $is_valid = null;
	private static $seconds = 0;
	private static $minutes = 0;
	private static $hours = 0;
	private static $days = 0;
	
	/**
	 * Returns the dateTime difference between a set timestamp and now.
	 * 
	 * @param String $date		A date in the future
	 * @return boolean			Trie on successful calculation, else false
	 */
	
	public static function calculate( $date )
	{
		
		try
		{
			
			date_default_timezone_set('Europe/Oslo');
			
			// Get datetimes
			$now = new DateTime(date("Y-m-d"));
			$date = new DateTime($date);
			
			// Make sure date is valid
			if ( self::is_valid($now, $date) )
			{
				// Get a DateInterval object and set difference
				$dateInterval = $now->diff($date);
				
				
				// Set difference
				self::$days = $dateInterval->days;
				self::$hours = $dateInterval->h;
				self::$minutes = $dateInterval->i;
				self::$seconds = $dateInterval->s;
				
				// Sucessful calculation
				return true;
			}
			
			return false;
		}
		catch (Exception $e)
		{
			return false;
		}
		
	}
	
	/**
	 * Returns the number of days remaining, following a 
	 * calculation  of the difference between two dateTimes.
	 * 
	 * @return int	The number of days remaining
	 */
	
	public static function get_days()
	{ 
		if ( self::$days > 0 )
		{
			return self::$days;
			
		}
		
		return false;
	}
	
	/**
	 * Returns the number of hours remaining, following a
	 * calculation  of the difference between two dateTimes.
	 *
	 * @return int	The number of hours remaining
	 */
	
	public static function get_hours()
	{
		if ( self::$hours > 0 )
		{
			return self::$hours;
		}
		
		return false;
	}
	
	/**
	 * Returns the number of minutes remaining, following a
	 * calculation  of the difference between two dateTimes.
	 *
	 * @return int	The number of minutes remaining
	 */
	
	public static function get_minutes()
	{
		if ( self::$minutes > 0 )
		{
			return self::$minutes;
			
		}
		
		return false;
	}
	
	/**
	 * Returns the number of seconds remaining, following a
	 * calculation  of the difference between two dateTimes.
	 *
	 * @return int	The number of seconds remaining
	 */
	
	public static function get_seconds()
	{
		if ( self::$seconds > 0 )
		{
			return self::$seconds;
		}
		
		return false;
	}

    public static function get_round_percentage( $start, $end )
    {
        // Set datetimes
        $start = new DateTime($start);
        $now = new DateTime(date("Y-m-d"));
        $end = new DateTime($end);

        if ( $end <= $now )
        {
        	return 0;
        }
        
        // Calculate number of days total
        $total_days = $start->diff($end);
        $total_days = $total_days->format('%a') + $total_days->format('%h')/24; // Days, plus hours divided by 24 (a day in hours)

        // Calculate number of days remaining
        $remaining_days = $now->diff($end);
        $remaining_days = $remaining_days->format('%a') + $remaining_days->format('%h')/24;
        
        // Calculate how much a day is in percentage
        $percentage = 100 / $total_days;

        // Calculate how many percentage (days) remains, and round down
        return floor($remaining_days * $percentage);
    }
	
	/**
	 * Returns the time difference as human-readable text
	 * 
	 * @return String	A difference as text
	 */
	
	public static function get_human_diff( )
	{
		
		// Make sure date is not expired
		if ( self::$is_valid )
		{
			// Filter days
			if ( self::get_days() > 0 ) {
				return self::get_conjugation(self::$days, "day");
			}
			// Filter hours
			if ( self::get_hours() > 0 ) {
				return self::get_conjugation(self::$hours, "hrs");
			}
			// Over 10 minutes
			if ( self::get_minutes() >= 10 ) {
				return self::get_conjugation(self::$minutes, "min");
			}
			// Under 10 minuttes
			return
			self::get_conjugation(self::$minutes, "min").' '.
			self::get_conjugation(self::$seconds, "sec");
			
		}
		
		// Expired
		return self::get_expired_message();
	}
	
	/**
	 * Will check if a given time difference is less than 0
	 * 
	 * @return boolean	True if dateTime is expired, else false
	 */
	
	private static function is_valid( DateTime $now, DateTime $comparision )
	{
		return self::$is_valid = ($now < $comparision);
	}
	
	/**
	 * Returns the expired message set in the translation array
	 * 
	 * @return String	The message defining an expired date.
	 */
	
	private static function get_expired_message()
	{
		return self::$translation['exp'];
	}
	
	/**
	 * Returns singular or plural version of words.
	 * 
	 * @param mixed $time		A time as an int
	 * @param String $key		The key in the translation array
	 */
	
	private static function get_conjugation($time, $key)
	{
		return ($time === 1) ? $time.' '.self::$translation[$key][0] : $time.' '.self::$translation[$key][1];
	}

}