<?php
 
 /**
  * This file is part of the Carbon package.
  *
  * (c) Brian Nesbitt <brian@nesbot.com>
  *
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
 namespace Carbon;
 
 use DateTimeInterface;
 use DateTimeZone;
 use InvalidArgumentException;
 
 class CarbonTimeZone extends DateTimeZone
 {
     public function __construct($timezone = null)
     {
         parent::__construct(static::getDateTimeZoneNameFromMixed($timezone));
     }
 
     protected static function getDateTimeZoneNameFromMixed($timezone)
     {
         if (is_null($timezone)) {
             $timezone = date_default_timezone_get();
         } elseif (is_numeric($timezone)) {
             if ($timezone <= -100 || $timezone >= 100) {
                 throw new InvalidArgumentException('Absolute timezone offset cannot be greater than 100.');
             }
 
             $timezone = ($timezone >= 0 ? '+' : '').$timezone.':00';
         }
 
         return $timezone;
     }
 
     protected static function getDateTimeZoneFromName(&$name)
     {
         return @timezone_open($name = (string) static::getDateTimeZoneNameFromMixed($name));
     }
 
     /**
      * Create a CarbonTimeZone from mixed input.
      *
      * @param DateTimeZone|string|int|null $object     original value to get CarbonTimeZone from it.
      * @param DateTimeZone|string|int|null $objectDump dump of the object for error messages.
      *
      * @return false|static
      */
     public static function instance($object = null, $objectDump = null)
     {
         $tz = $object;
 
         if ($tz instanceof static) {
             return $tz;
         }
 
         if ($tz === null) {
             return new static();
         }
 
         if (!$tz instanceof DateTimeZone) {
             $tz = static::getDateTimeZoneFromName($object);
         }
 
         if ($tz === false) {
             if (Carbon::isStrictModeEnabled()) {
                 throw new InvalidArgumentException('Unknown or bad timezone ('.($objectDump ?: $object).')');
             }
 
             return false;
         }
 
         return new static($tz->getName());
     }
 
     /**
      * Returns abbreviated name of the current timezone according to DST setting.
      *
      * @param bool $dst
      *
      * @return string
      */
     public function getAbbreviatedName($dst = false)
     {
         $name = $this->getName();
 
         foreach ($this->listAbbreviations() as $abbreviation => $zones) {
             foreach ($zones as $zone) {
                 if ($zone['timezone_id'] === $name && $zone['dst'] == $dst) {
                     return $abbreviation;
                 }
             }
         }
 
         return 'unknown';
     }
 
     /**
      * @alias getAbbreviatedName
      *
      * Returns abbreviated name of the current timezone according to DST setting.
      *
      * @param bool $dst
      *
      * @return string
      */
     public function getAbbr($dst = false)
     {
         return $this->getAbbreviatedName($dst);
     }
 
     /**
      * Get the offset as string "sHH:MM" (such as "+00:00" or "-12:30").
      *
      * @param DateTimeInterface|null $date
      *
      * @return string
      */
     public function toOffsetName(DateTimeInterface $date = null)
     {
         $minutes = floor($this->getOffset($date ?: Carbon::now($this)) / 60);
 
         $hours = floor($minutes / 60);
 
         $minutes = str_pad((string) (abs($minutes) % 60), 2, '0', STR_PAD_LEFT);
 
         return ($hours < 0 ? '-' : '+').str_pad((string) abs($hours), 2, '0', STR_PAD_LEFT).":$minutes";
     }
 
     /**
      * Returns a new CarbonTimeZone object using the offset string instead of region string.
      *
      * @param DateTimeInterface|null $date
      *
      * @return CarbonTimeZone
      */
     public function toOffsetTimeZone(DateTimeInterface $date = null)
     {
         return new static($this->toOffsetName($date));
     }
 
     /**
      * Returns the first region string (such as "America/Toronto") that matches the current timezone.
      *
      * @see timezone_name_from_abbr native PHP function.
      *
      * @param DateTimeInterface|null $date
      * @param int                    $isDst
      *
      * @return string
      */
     public function toRegionName(DateTimeInterface $date = null, $isDst = 1)
     {
         $name = $this->getName();
         $firstChar = substr($name, 0, 1);
 
         if ($firstChar !== '+' && $firstChar !== '-') {
             return $name;
         }
 
         return @timezone_name_from_abbr('', @$this->getOffset($date ?: Carbon::now($this)) ?: 0, $isDst);
     }
 
     /**
      * Returns a new CarbonTimeZone object using the region string instead of offset string.
      *
      * @param DateTimeInterface|null $date
      *
      * @return CarbonTimeZone|false
      */
     public function toRegionTimeZone(DateTimeInterface $date = null)
     {
         $tz = $this->toRegionName($date);
 
         if ($tz === false) {
             if (Carbon::isStrictModeEnabled()) {
                 throw new InvalidArgumentException('Unknown timezone for offset '.$this->getOffset($date ?: Carbon::now($this)).' seconds.');
             }
 
             return false;
         }
 
         return new static($tz);
     }
 
     /**
      * Cast to string (get timezone name).
      *
      * @return string
      */
     public function __toString()
     {
         return $this->getName();
     }
 
     /**
      * Create a CarbonTimeZone from mixed input.
      *
      * @param DateTimeZone|string|int|null $object
      *
      * @return false|static
      */
     public static function create($object = null)
     {
         return static::instance($object);
     }
 }