/library/Utility.php

<?php
require_once "PasswordHash.php";
require_once "Vars.php";

class Utility {

	public static function getSQLConnection() {
		if($mysqli == null) {
			$mysqli = new mysqli(Config::dbserver,Config::dbusername,Config::dbpassword,Config::dbname);
			if ($mysqli->connect_errno) {
				trigger_error($mysqli->error,E_USER_ERROR);
			}
		}
		return $mysqli;
	}

	public static function getPasswordHasher() {
		return $hasher = new PasswordHash(Config::passwordRounds, FALSE);
	}



	/** 
	 * Interval formatting, will use the two biggest interval parts. 
	 * On small intervals, you get minutes and seconds. 
	 * On big intervals, you get months and days. 
	 * Only the two biggest parts are used. 
	 */ 
	public static function formatDateDiff($interval) { 
		$doPlural = function($nb,$str){return $nb>1?$str.'s':$str;}; // adds plurals 
		
		$format = array(); 
		if($interval->y !== 0) { 
			$format[] = "%y ".$doPlural($interval->y, "year"); 
		} 
		if($interval->m !== 0) { 
			$format[] = "%m ".$doPlural($interval->m, "month"); 
		} 
		if($interval->d !== 0) { 
			$format[] = "%d ".$doPlural($interval->d, "day"); 
		} 
		if($interval->h !== 0) { 
			$format[] = "%h ".$doPlural($interval->h, "hour"); 
		} 
		if($interval->i !== 0) { 
			$format[] = "%i ".$doPlural($interval->i, "minute"); 
		} 
		if($interval->s !== 0) { 
			if(!count($format)) { 
				return $interval->format("%s ".$doPlural($interval->s, "second")); 
			} else { 
				$format[] = "%s ".$doPlural($interval->s, "second"); 
			} 
		} 
		
		// Use the two largest
		if(count($format) > 1) { 
			$format = array_shift($format)." and ".array_shift($format); 
		} elseif(count($format) == 0) {
			return "less than a second";
		} else { 
			$format = array_pop($format); 
		} 
		
		return $interval->format($format); 
	} 
}