DaSourcerer/yii2-yiiboard

<?php
namespace app\modules\yboard\components;

use app\modules\yboard\models\YBoardMember;
use DateTime;
use DateTimeZone;

class DateTimeCalculation {
    static public function shortDate($timestamp) {
        $df = \Yii::$app->formatter;
        return $df->asDate(self::userTimestamp($timestamp), 'short');
    }
    
    static public function longDate($timestamp) {
        $df = \Yii::$app->formatter;
        return $df->asDate(self::userTimestamp($timestamp), 'long');
    }
    
    static public function medium($timestamp) { 
        $df = \Yii::$app->formatter;
        return $df->asDatetime(self::userTimestamp($timestamp), 'medium');
    }
    
    static public function short($timestamp) { 
        $df = \Yii::$app->formatter;
        return $df->asDatetime(self::userTimestamp($timestamp), 'short');
    }
    
    static public function long($timestamp) {
        $df = \Yii::$app->formatter;
        return $df->asDatetime(self::userTimestamp($timestamp), 'long');
    }
    
    static public function full($timestamp) {
        $df = \Yii::$app->formatter;
        return $df->asDatetime(self::userTimestamp($timestamp), 'full') . ' ' . self::userTimezoneNotation();
    }
    
    /**
     * Precursor function to convert timestamp for user
     * @param string $timestamp timestamp format 'yyyy-MM-dd hh:mm:ss'
     * @return string timestamp format 'yyyy-MM-dd hh:mm:ss'
     */
    static public function userTimestamp($timestamp) {  
        if(!is_numeric($timestamp))  //skip for unix timestamps      
        {
            $dt = new DateTime($timestamp);
            $timestamp = $dt->getTimestamp();
        }
        
        if(\Yii::$app->user->isGuest) {
            return $timestamp;
        }
        $timezone = YBoardMember::findOne(\Yii::$app->user->id);
        
        if($timezone==null||!isset($timezone->profile->timezone)) {
            return $timestamp;
        } 
        else if(empty($timezone->profile->timezone))
        {
            return $timestamp;            
        }else {
            return self::convertTimestamp($timestamp, $timezone->profile->timezone);
        }
    }
    
    /**
     * Convert timestamp from server time to time in target timezone
     * @param string $timestamp timestamp format 'yyyy-MM-dd hh:mm:ss'
     * @param string $timezone e.g. 'Europe/Paris'
     * @return string timestamp format 'yyyy-MM-dd hh:mm:ss'
     */
    static public function convertTimestamp($timestamp, $timezone) {
        $datetime = new DateTime('', new DateTimeZone($timezone));
        $datetime->setTimeStamp($timestamp);
        return $datetime->format('Y-m-d H:i:s');
    }
    
    /**
     * Return the timezone notation for the user
     * @return string
     */
    static public function userTimezoneNotation() {
        if(\Yii::$app->user->isGuest) {
            $timezone = date_default_timezone_get();
        } else {
            $timezone = YBoardMember::findOne(\Yii::$app->user->id);
            if(isset($timezone->profile->timezone))
                $timezone = $timezone->profile->timezone;
                
            if(empty($timezone)) {
                $timezone = date_default_timezone_get();
            }
        }
        $dateTime = new DateTime(); 
        $dateTime->setTimeZone(new DateTimeZone($timezone)); 
        return $dateTime->format('T'); 
    }
    
    /**
     * Return the difference btn dates formatted
     * inputs are unix timestamps
     * @return string
     */
    static public function getDiff($past, $future) 
    {
        $days = floor(abs(($future-$past)/(60*60*24)));
        $secs = abs(($future-$past)%(60*60*24));        
        $hrs = ceil($secs/(60*60));
        
        return ['days'=>$days, 'hours'=>$hrs];
    }
}