<?php

namespace Carbon;

use Closure;
use DateInterval;
use InvalidArgumentException;
use ReflectionClass;
use ReflectionFunction;
use ReflectionMethod;
use Symfony\Component\Translation\TranslatorInterface;

/**
 * A simple API extension for DateInterval.
 * The implementation provides helpers to handle weeks but only days are saved.
 * Weeks are calculated based on the total days of the current instance.
 *
 * @property int $years Total years of the current interval.
 * @property int $months Total months of the current interval.
 * @property int $weeks Total weeks of the current interval calculated from the days.
 * @property int $dayz Total days of the current interval (weeks * 7 + days).
 * @property int $hours Total hours of the current interval.
 * @property int $minutes Total minutes of the current interval.
 * @property int $seconds Total seconds of the current interval.
 * @property-read int $dayzExcludeWeeks Total days remaining in the final week of the current instance (days % 7).
 * @property-read int $daysExcludeWeeks alias of dayzExcludeWeeks
 * @property-read float $totalYears Number of years equivalent to the interval.
 * @property-read float $totalMonths Number of months equivalent to the interval.
 * @property-read float $totalWeeks Number of weeks equivalent to the interval.
 * @property-read float $totalDays Number of days equivalent to the interval.
 * @property-read float $totalDayz Alias for totalDays.
 * @property-read float $totalHours Number of hours equivalent to the interval.
 * @property-read float $totalMinutes Number of minutes equivalent to the interval.
 * @property-read float $totalSeconds Number of seconds equivalent to the interval.
 *
 * @method static CarbonInterval years($years = 1) Create instance specifying a number of years.
 * @method static CarbonInterval year($years = 1) Alias for years()
 * @method static CarbonInterval months($months = 1) Create instance specifying a number of months.
 * @method static CarbonInterval month($months = 1) Alias for months()
 * @method static CarbonInterval weeks($weeks = 1) Create instance specifying a number of weeks.
 * @method static CarbonInterval week($weeks = 1) Alias for weeks()
 * @method static CarbonInterval days($days = 1) Create instance specifying a number of days.
 * @method static CarbonInterval dayz($days = 1) Alias for days()
 * @method static CarbonInterval day($days = 1) Alias for days()
 * @method static CarbonInterval hours($hours = 1) Create instance specifying a number of hours.
 * @method static CarbonInterval hour($hours = 1) Alias for hours()
 * @method static CarbonInterval minutes($minutes = 1) Create instance specifying a number of minutes.
 * @method static CarbonInterval minute($minutes = 1) Alias for minutes()
 * @method static CarbonInterval seconds($seconds = 1) Create instance specifying a number of seconds.
 * @method static CarbonInterval second($seconds = 1) Alias for seconds()
 * @method CarbonInterval years($years = 1) Set the years portion of the current interval.
 * @method CarbonInterval year($years = 1) Alias for years().
 * @method CarbonInterval months($months = 1) Set the months portion of the current interval.
 * @method CarbonInterval month($months = 1) Alias for months().
 * @method CarbonInterval weeks($weeks = 1) Set the weeks portion of the current interval.  Will overwrite dayz value.
 * @method CarbonInterval week($weeks = 1) Alias for weeks().
 * @method CarbonInterval days($days = 1) Set the days portion of the current interval.
 * @method CarbonInterval dayz($days = 1) Alias for days().
 * @method CarbonInterval day($days = 1) Alias for days().
 * @method CarbonInterval hours($hours = 1) Set the hours portion of the current interval.
 * @method CarbonInterval hour($hours = 1) Alias for hours().
 * @method CarbonInterval minutes($minutes = 1) Set the minutes portion of the current interval.
 * @method CarbonInterval minute($minutes = 1) Alias for minutes().
 * @method CarbonInterval seconds($seconds = 1) Set the seconds portion of the current interval.
 * @method CarbonInterval second($seconds = 1) Alias for seconds().
 */
class CarbonInterval extends DateInterval
{
	/** Interval spec period designators */
	const PERIOD_PREFIX = 'P';
	const PERIOD_YEARS = 'Y';
	const PERIOD_MONTHS = 'M';
	const PERIOD_DAYS = 'D';
	const PERIOD_TIME_PREFIX = 'T';
	const PERIOD_HOURS = 'H';
	const PERIOD_MINUTES = 'M';
	const PERIOD_SECONDS = 'S';

	/**
	 * Before PHP 5.4.20/5.5.4 instead of FALSE days will be set to -99999 when the interval instance
	 * was created by DateTime::diff().
	 */
	const PHP_DAYS_FALSE = -99999;

	/**
	 * A translator to ... er ... translate stuff
	 *
	 * @var \Symfony\Component\Translation\TranslatorInterface
	 */
	protected static $translator;

	/** @var array|null */
	protected static $cascadeFactors;

	/** @var array|null */
	private static $flipCascadeFactors;

	/**
	 * The registered macros.
	 *
	 * @var array
	 */
	protected static $macros = array();


	/**
	 * Mapping of units and factors for cascading.
	 *
	 * Should only be modified by changing the factors or referenced constants.
	 *
	 * @return array
	 */
	public static function getCascadeFactors()
	{
		return static::$cascadeFactors ?: array(
		    'minutes' => array(Carbon::SECONDS_PER_MINUTE, 'seconds'),
		    'hours' => array(Carbon::MINUTES_PER_HOUR, 'minutes'),
		    'dayz' => array(Carbon::HOURS_PER_DAY, 'hours'),
		    'months' => array(Carbon::DAYS_PER_WEEK * Carbon::WEEKS_PER_MONTH, 'dayz'),
		    'years' => array(Carbon::MONTHS_PER_YEAR, 'months'),
		);
	}


	private static function standardizeUnit($unit)
	{
		$unit = rtrim($unit, 'sz').'s';

		return $unit === 'days' ? 'dayz' : $unit;
	}


	private static function getFlipCascadeFactors()
	{
		if (!self::$flipCascadeFactors) {
		    self::$flipCascadeFactors = array();
		    foreach (static::getCascadeFactors() as $to => $tuple) {
		        list($factor, $from) = $tuple;

		        self::$flipCascadeFactors[self::standardizeUnit($from)] = array(self::standardizeUnit($to), $factor);
		    }
		}

		return self::$flipCascadeFactors;
	}


	/**
	 * @param array $cascadeFactors
	 */
	public static function setCascadeFactors(array $cascadeFactors)
	{
		self::$flipCascadeFactors = null;
		static::$cascadeFactors = $cascadeFactors;
	}


	/**
	 * Determine if the interval was created via DateTime:diff() or not.
	 *
	 * @param DateInterval $interval
	 *
	 * @return bool
	 */
	private static function wasCreatedFromDiff(DateInterval $interval)
	{
		return $interval->days !== false && $interval->days !== static::PHP_DAYS_FALSE;
	}


	/**
	 * Create a new CarbonInterval instance.
	 *
	 * @param int $years
	 * @param int $months
	 * @param int $weeks
	 * @param int $days
	 * @param int $hours
	 * @param int $minutes
	 * @param int $seconds
	 */
	public function __construct(
		$years = 1,
		$months = null,
		$weeks = null,
		$days = null,
		$hours = null,
		$minutes = null,
		$seconds = null,
	) {
		$spec = $years;

		if (!is_string($spec) || floatval($years) || preg_match('/^[0-9.]/', $years)) {
		    $spec = static::PERIOD_PREFIX;

		    $spec .= $years > 0 ? $years.static::PERIOD_YEARS : '';
		    $spec .= $months > 0 ? $months.static::PERIOD_MONTHS : '';

		    $specDays = 0;
		    $specDays += $weeks > 0 ? $weeks * static::getDaysPerWeek() : 0;
		    $specDays += $days > 0 ? $days : 0;

		    $spec .= $specDays > 0 ? $specDays.static::PERIOD_DAYS : '';

		    if ($hours > 0 || $minutes > 0 || $seconds > 0) {
		        $spec .= static::PERIOD_TIME_PREFIX;
		        $spec .= $hours > 0 ? $hours.static::PERIOD_HOURS : '';
		        $spec .= $minutes > 0 ? $minutes.static::PERIOD_MINUTES : '';
		        $spec .= $seconds > 0 ? $seconds.static::PERIOD_SECONDS : '';
		    }

		    if ($spec === static::PERIOD_PREFIX) {
		        // Allow the zero interval.
		        $spec .= '0'.static::PERIOD_YEARS;
		    }
		}

		parent::__construct($spec);
	}


	/**
	 * Returns the factor for a given source-to-target couple.
	 *
	 * @param string $source
	 * @param string $target
	 *
	 * @return int|null
	 */
	public static function getFactor($source, $target)
	{
		$source = self::standardizeUnit($source);
		$target = self::standardizeUnit($target);
		$factors = static::getFlipCascadeFactors();
		if (isset($factors[$source])) {
		    list($to, $factor) = $factors[$source];
		    if ($to === $target) {
		        return $factor;
		    }
		}

		return null;
	}


	/**
	 * Returns current config for days per week.
	 *
	 * @return int
	 */
	public static function getDaysPerWeek()
	{
		return static::getFactor('dayz', 'weeks') ?: Carbon::DAYS_PER_WEEK;
	}


	/**
	 * Returns current config for hours per day.
	 *
	 * @return int
	 */
	public static function getHoursPerDay()
	{
		return static::getFactor('hours', 'dayz') ?: Carbon::HOURS_PER_DAY;
	}


	/**
	 * Returns current config for minutes per hour.
	 *
	 * @return int
	 */
	public static function getMinutesPerHours()
	{
		return static::getFactor('minutes', 'hours') ?: Carbon::MINUTES_PER_HOUR;
	}


	/**
	 * Returns current config for seconds per minute.
	 *
	 * @return int
	 */
	public static function getSecondsPerMinutes()
	{
		return static::getFactor('seconds', 'minutes') ?: Carbon::SECONDS_PER_MINUTE;
	}


	/**
	 * Create a new CarbonInterval instance from specific values.
	 * This is an alias for the constructor that allows better fluent
	 * syntax as it allows you to do CarbonInterval::create(1)->fn() rather than
	 * (new CarbonInterval(1))->fn().
	 *
	 * @param int $years
	 * @param int $months
	 * @param int $weeks
	 * @param int $days
	 * @param int $hours
	 * @param int $minutes
	 * @param int $seconds
	 *
	 * @return static
	 */
	public static function create(
		$years = 1,
		$months = null,
		$weeks = null,
		$days = null,
		$hours = null,
		$minutes = null,
		$seconds = null,
	) {
		return new static($years, $months, $weeks, $days, $hours, $minutes, $seconds);
	}


	/**
	 * Get a copy of the instance.
	 *
	 * @return static
	 */
	public function copy()
	{
		$date = new static($this->spec());
		$date->invert = $this->invert;

		return $date;
	}


	/**
	 * Provide static helpers to create instances.  Allows CarbonInterval::years(3).
	 *
	 * Note: This is done using the magic method to allow static and instance methods to
	 *       have the same names.
	 *
	 * @param string $name
	 * @param array  $args
	 *
	 * @return static
	 */
	public static function __callStatic($name, $args)
	{
		$arg = count($args) === 0 ? 1 : $args[0];

		switch ($name) {
		    case 'years':
		    case 'year':
		        return new static($arg);

		    case 'months':
		    case 'month':
		        return new static(null, $arg);

		    case 'weeks':
		    case 'week':
		        return new static(null, null, $arg);

		    case 'days':
		    case 'dayz':
		    case 'day':
		        return new static(null, null, null, $arg);

		    case 'hours':
		    case 'hour':
		        return new static(null, null, null, null, $arg);

		    case 'minutes':
		    case 'minute':
		        return new static(null, null, null, null, null, $arg);

		    case 'seconds':
		    case 'second':
		        return new static(null, null, null, null, null, null, $arg);
		}

		if (static::hasMacro($name)) {
		    return call_user_func_array(
		        array(new static(0), $name), $args
		    );
		}
	}


	/**
	 * Creates a CarbonInterval from string.
	 *
	 * Format:
	 *
	 * Suffix | Unit    | Example | DateInterval expression
	 * -------|---------|---------|------------------------
	 * y      | years   |   1y    | P1Y
	 * mo     | months  |   3mo   | P3M
	 * w      | weeks   |   2w    | P2W
	 * d      | days    |  28d    | P28D
	 * h      | hours   |   4h    | PT4H
	 * m      | minutes |  12m    | PT12M
	 * s      | seconds |  59s    | PT59S
	 *
	 * e. g. `1w 3d 4h 32m 23s` is converted to 10 days 4 hours 32 minutes and 23 seconds.
	 *
	 * Special cases:
	 *  - An empty string will return a zero interval
	 *  - Fractions are allowed for weeks, days, hours and minutes and will be converted
	 *    and rounded to the next smaller value (caution: 0.5w = 4d)
	 *
	 * @param string $intervalDefinition
	 *
	 * @return static
	 */
	public static function fromString($intervalDefinition)
	{
		if (empty($intervalDefinition)) {
		    return new static(0);
		}

		$years = 0;
		$months = 0;
		$weeks = 0;
		$days = 0;
		$hours = 0;
		$minutes = 0;
		$seconds = 0;

		$pattern = '/(\d+(?:\.\d+)?)\h*([^\d\h]*)/i';
		preg_match_all($pattern, $intervalDefinition, $parts, PREG_SET_ORDER);
		while ($match = array_shift($parts)) {
		    list($part, $value, $unit) = $match;
		    $intValue = intval($value);
		    $fraction = floatval($value) - $intValue;
		    switch (strtolower($unit)) {
		        case 'year':
		        case 'years':
		        case 'y':
		            $years += $intValue;
		            break;

		        case 'month':
		        case 'months':
		        case 'mo':
		            $months += $intValue;
		            break;

		        case 'week':
		        case 'weeks':
		        case 'w':
		            $weeks += $intValue;
		            if ($fraction) {
		                $parts[] = array(null, $fraction * static::getDaysPerWeek(), 'd');
		            }
		            break;

		        case 'day':
		        case 'days':
		        case 'd':
		            $days += $intValue;
		            if ($fraction) {
		                $parts[] = array(null, $fraction * static::getHoursPerDay(), 'h');
		            }
		            break;

		        case 'hour':
		        case 'hours':
		        case 'h':
		            $hours += $intValue;
		            if ($fraction) {
		                $parts[] = array(null, $fraction * static::getMinutesPerHours(), 'm');
		            }
		            break;

		        case 'minute':
		        case 'minutes':
		        case 'm':
		            $minutes += $intValue;
		            if ($fraction) {
		                $seconds += round($fraction * static::getSecondsPerMinutes());
		            }
		            break;

		        case 'second':
		        case 'seconds':
		        case 's':
		            $seconds += $intValue;
		            break;

		        default:
		            throw new InvalidArgumentException(
		                sprintf('Invalid part %s in definition %s', $part, $intervalDefinition)
		            );
		    }
		}

		return new static($years, $months, $weeks, $days, $hours, $minutes, $seconds);
	}


	/**
	 * Create a CarbonInterval instance from a DateInterval one.  Can not instance
	 * DateInterval objects created from DateTime::diff() as you can't externally
	 * set the $days field.
	 *
	 * Pass false as second argument to get a microseconds-precise interval. Else
	 * microseconds in the original interval will not be kept.
	 *
	 * @param DateInterval $di
	 * @param bool         $trimMicroseconds (true by default)
	 *
	 * @return static
	 */
	public static function instance(DateInterval $di, $trimMicroseconds = true)
	{
		$microseconds = $trimMicroseconds || version_compare(PHP_VERSION, '7.1.0-dev', '<') ? 0 : $di->f;
		$instance = new static(static::getDateIntervalSpec($di));
		if ($microseconds) {
		    $instance->f = $microseconds;
		}
		$instance->invert = $di->invert;
		foreach (array('y', 'm', 'd', 'h', 'i', 's') as $unit) {
		    if ($di->$unit < 0) {
		        $instance->$unit *= -1;
		    }
		}

		return $instance;
	}


	/**
	 * Make a CarbonInterval instance from given variable if possible.
	 *
	 * Always return a new instance. Parse only strings and only these likely to be intervals (skip dates
	 * and recurrences). Throw an exception for invalid format, but otherwise return null.
	 *
	 * @param mixed $var
	 *
	 * @return static|null
	 */
	public static function make($var)
	{
		if ($var instanceof DateInterval) {
		    return static::instance($var);
		}

		if (is_string($var)) {
		    $var = trim($var);

		    if (substr($var, 0, 1) === 'P') {
		        return new static($var);
		    }

		    if (preg_match('/^(?:\h*\d+(?:\.\d+)?\h*[a-z]+)+$/i', $var)) {
		        return static::fromString($var);
		    }
		}
	}


	/**
	 * Initialize the translator instance if necessary.
	 *
	 * @return \Symfony\Component\Translation\TranslatorInterface
	 */
	protected static function translator()
	{
		if (static::$translator === null) {
		    static::$translator = Translator::get();
		}

		return static::$translator;
	}


	/**
	 * Get the translator instance in use.
	 *
	 * @return \Symfony\Component\Translation\TranslatorInterface
	 */
	public static function getTranslator()
	{
		return static::translator();
	}


	/**
	 * Set the translator instance to use.
	 *
	 * @param TranslatorInterface $translator
	 */
	public static function setTranslator(TranslatorInterface $translator)
	{
		static::$translator = $translator;
	}


	/**
	 * Get the current translator locale.
	 *
	 * @return string
	 */
	public static function getLocale()
	{
		return static::translator()->getLocale();
	}


	/**
	 * Set the current translator locale.
	 *
	 * @param string $locale
	 */
	public static function setLocale($locale)
	{
		return static::translator()->setLocale($locale) !== false;
	}


	/**
	 * Get a part of the CarbonInterval object.
	 *
	 * @param string $name
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return int|float
	 */
	public function __get($name)
	{
		if (substr($name, 0, 5) === 'total') {
		    return $this->total(substr($name, 5));
		}

		switch ($name) {
		    case 'years':
		        return $this->y;

		    case 'months':
		        return $this->m;

		    case 'dayz':
		        return $this->d;

		    case 'hours':
		        return $this->h;

		    case 'minutes':
		        return $this->i;

		    case 'seconds':
		        return $this->s;

		    case 'weeks':
		        return (int) floor($this->d / static::getDaysPerWeek());

		    case 'daysExcludeWeeks':
		    case 'dayzExcludeWeeks':
		        return $this->d % static::getDaysPerWeek();

		    default:
		        throw new InvalidArgumentException(sprintf("Unknown getter '%s'", $name));
		}
	}


	/**
	 * Set a part of the CarbonInterval object.
	 *
	 * @param string $name
	 * @param int    $val
	 *
	 * @throws \InvalidArgumentException
	 */
	public function __set($name, $val)
	{
		switch ($name) {
		    case 'years':
		        $this->y = $val;
		        break;

		    case 'months':
		        $this->m = $val;
		        break;

		    case 'weeks':
		        $this->d = $val * static::getDaysPerWeek();
		        break;

		    case 'dayz':
		        $this->d = $val;
		        break;

		    case 'hours':
		        $this->h = $val;
		        break;

		    case 'minutes':
		        $this->i = $val;
		        break;

		    case 'seconds':
		        $this->s = $val;
		        break;
		}
	}


	/**
	 * Allow setting of weeks and days to be cumulative.
	 *
	 * @param int $weeks Number of weeks to set
	 * @param int $days  Number of days to set
	 *
	 * @return static
	 */
	public function weeksAndDays($weeks, $days)
	{
		$this->dayz = ($weeks * static::getDaysPerWeek()) + $days;

		return $this;
	}


	/**
	 * Register a custom macro.
	 *
	 * @param string          $name
	 * @param object|callable $macro
	 *
	 * @return void
	 */
	public static function macro($name, $macro)
	{
		static::$macros[$name] = $macro;
	}


	/**
	 * Remove all macros.
	 */
	public static function resetMacros()
	{
		static::$macros = array();
	}


	/**
	 * Register macros from a mixin object.
	 *
	 * @param object $mixin
	 *
	 * @throws \ReflectionException
	 *
	 * @return void
	 */
	public static function mixin($mixin)
	{
		$reflection = new ReflectionClass($mixin);

		$methods = $reflection->getMethods(
		    ReflectionMethod::IS_PUBLIC | ReflectionMethod::IS_PROTECTED
		);

		foreach ($methods as $method) {
		    $method->setAccessible(true);

		    static::macro($method->name, $method->invoke($mixin));
		}
	}


	/**
	 * Check if macro is registered.
	 *
	 * @param string $name
	 *
	 * @return bool
	 */
	public static function hasMacro($name)
	{
		return isset(static::$macros[$name]);
	}


	/**
	 * Call given macro.
	 *
	 * @param string $name
	 * @param array  $parameters
	 *
	 * @return mixed
	 */
	protected function callMacro($name, $parameters)
	{
		$macro = static::$macros[$name];

		$reflection = new ReflectionFunction($macro);

		$reflectionParameters = $reflection->getParameters();

		$expectedCount = count($reflectionParameters);
		$actualCount = count($parameters);

		if ($expectedCount > $actualCount && $reflectionParameters[$expectedCount - 1]->name === 'self') {
		    for ($i = $actualCount; $i < $expectedCount - 1; $i++) {
		        $parameters[] = $reflectionParameters[$i]->getDefaultValue();
		    }

		    $parameters[] = $this;
		}

		if ($macro instanceof Closure && method_exists($macro, 'bindTo')) {
		    $macro = $macro->bindTo($this, get_class($this));
		}

		return call_user_func_array($macro, $parameters);
	}


	/**
	 * Allow fluent calls on the setters... CarbonInterval::years(3)->months(5)->day().
	 *
	 * Note: This is done using the magic method to allow static and instance methods to
	 *       have the same names.
	 *
	 * @param string $name
	 * @param array  $args
	 *
	 * @return static
	 */
	public function __call($name, $args)
	{
		if (static::hasMacro($name)) {
		    return $this->callMacro($name, $args);
		}

		$arg = count($args) === 0 ? 1 : $args[0];

		switch ($name) {
		    case 'years':
		    case 'year':
		        $this->years = $arg;
		        break;

		    case 'months':
		    case 'month':
		        $this->months = $arg;
		        break;

		    case 'weeks':
		    case 'week':
		        $this->dayz = $arg * static::getDaysPerWeek();
		        break;

		    case 'days':
		    case 'dayz':
		    case 'day':
		        $this->dayz = $arg;
		        break;

		    case 'hours':
		    case 'hour':
		        $this->hours = $arg;
		        break;

		    case 'minutes':
		    case 'minute':
		        $this->minutes = $arg;
		        break;

		    case 'seconds':
		    case 'second':
		        $this->seconds = $arg;
		        break;
		}

		return $this;
	}


	/**
	 * Get the current interval in a human readable format in the current locale.
	 *
	 * @param bool $short (false by default), returns short units if true
	 *
	 * @return string
	 */
	public function forHumans($short = false)
	{
		$periods = array(
		    'year' => array('y', $this->years),
		    'month' => array('m', $this->months),
		    'week' => array('w', $this->weeks),
		    'day' => array('d', $this->daysExcludeWeeks),
		    'hour' => array('h', $this->hours),
		    'minute' => array('min', $this->minutes),
		    'second' => array('s', $this->seconds),
		);

		$parts = array();
		foreach ($periods as $unit => $options) {
		    list($shortUnit, $count) = $options;
		    if ($count > 0) {
		        $parts[] = static::translator()->transChoice($short ? $shortUnit : $unit, $count, array(':count' => $count));
		    }
		}

		return implode(' ', $parts);
	}


	/**
	 * Format the instance as a string using the forHumans() function.
	 *
	 * @return string
	 */
	public function __toString()
	{
		return $this->forHumans();
	}


	/**
	 * Convert the interval to a CarbonPeriod.
	 *
	 * @return CarbonPeriod
	 */
	public function toPeriod()
	{
		return CarbonPeriod::createFromArray(
		    array_merge(array($this), func_get_args())
		);
	}


	/**
	 * Invert the interval.
	 *
	 * @return $this
	 */
	public function invert()
	{
		$this->invert = $this->invert ? 0 : 1;

		return $this;
	}


	/**
	 * Add the passed interval to the current instance.
	 *
	 * @param DateInterval $interval
	 *
	 * @return static
	 */
	public function add(DateInterval $interval)
	{
		$sign = ($this->invert === 1) !== ($interval->invert === 1) ? -1 : 1;

		if (static::wasCreatedFromDiff($interval)) {
		    $this->dayz += $interval->days * $sign;
		} else {
		    $this->years += $interval->y * $sign;
		    $this->months += $interval->m * $sign;
		    $this->dayz += $interval->d * $sign;
		    $this->hours += $interval->h * $sign;
		    $this->minutes += $interval->i * $sign;
		    $this->seconds += $interval->s * $sign;
		}

		if (($this->years || $this->months || $this->dayz || $this->hours || $this->minutes || $this->seconds) &&
		    $this->years <= 0 && $this->months <= 0 && $this->dayz <= 0 && $this->hours <= 0 && $this->minutes <= 0 && $this->seconds <= 0
		) {
		    $this->years *= -1;
		    $this->months *= -1;
		    $this->dayz *= -1;
		    $this->hours *= -1;
		    $this->minutes *= -1;
		    $this->seconds *= -1;
		    $this->invert();
		}

		return $this;
	}


	/**
	 * Multiply current instance given number of times
	 *
	 * @param float $factor
	 *
	 * @return $this
	 */
	public function times($factor)
	{
		if ($factor < 0) {
		    $this->invert = $this->invert ? 0 : 1;
		    $factor = -$factor;
		}

		$this->years = (int) round($this->years * $factor);
		$this->months = (int) round($this->months * $factor);
		$this->dayz = (int) round($this->dayz * $factor);
		$this->hours = (int) round($this->hours * $factor);
		$this->minutes = (int) round($this->minutes * $factor);
		$this->seconds = (int) round($this->seconds * $factor);

		return $this;
	}


	/**
	 * Get the interval_spec string of a date interval.
	 *
	 * @param DateInterval $interval
	 *
	 * @return string
	 */
	public static function getDateIntervalSpec(DateInterval $interval)
	{
		$date = array_filter(array(
		    static::PERIOD_YEARS => abs($interval->y),
		    static::PERIOD_MONTHS => abs($interval->m),
		    static::PERIOD_DAYS => abs($interval->d),
		));

		$time = array_filter(array(
		    static::PERIOD_HOURS => abs($interval->h),
		    static::PERIOD_MINUTES => abs($interval->i),
		    static::PERIOD_SECONDS => abs($interval->s),
		));

		$specString = static::PERIOD_PREFIX;

		foreach ($date as $key => $value) {
		    $specString .= $value.$key;
		}

		if (count($time) > 0) {
		    $specString .= static::PERIOD_TIME_PREFIX;
		    foreach ($time as $key => $value) {
		        $specString .= $value.$key;
		    }
		}

		return $specString === static::PERIOD_PREFIX ? 'PT0S' : $specString;
	}


	/**
	 * Get the interval_spec string.
	 *
	 * @return string
	 */
	public function spec()
	{
		return static::getDateIntervalSpec($this);
	}


	/**
	 * Comparing 2 date intervals.
	 *
	 * @param DateInterval $a
	 * @param DateInterval $b
	 *
	 * @return int
	 */
	public static function compareDateIntervals(DateInterval $a, DateInterval $b)
	{
		$current = Carbon::now();
		$passed = $current->copy()->add($b);
		$current->add($a);

		if ($current < $passed) {
		    return -1;
		}
		if ($current > $passed) {
		    return 1;
		}

		return 0;
	}


	/**
	 * Comparing with passed interval.
	 *
	 * @param DateInterval $interval
	 *
	 * @return int
	 */
	public function compare(DateInterval $interval)
	{
		return static::compareDateIntervals($this, $interval);
	}


	/**
	 * Convert overflowed values into bigger units.
	 *
	 * @return $this
	 */
	public function cascade()
	{
		foreach (static::getFlipCascadeFactors() as $source => $cascade) {
		    list($target, $factor) = $cascade;

		    if ($source === 'dayz' && $target === 'weeks') {
		        continue;
		    }

		    $value = $this->$source;
		    $this->$source = $modulo = $value % $factor;
		    $this->$target += ($value - $modulo) / $factor;
		}

		return $this;
	}


	/**
	 * Get amount of given unit equivalent to the interval.
	 *
	 * @param string $unit
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return float
	 */
	public function total($unit)
	{
		$realUnit = $unit = strtolower($unit);

		if (in_array($unit, array('days', 'weeks'))) {
		    $realUnit = 'dayz';
		} elseif (!in_array($unit, array('seconds', 'minutes', 'hours', 'dayz', 'months', 'years'))) {
		    throw new InvalidArgumentException("Unknown unit '$unit'.");
		}

		$result = 0;
		$cumulativeFactor = 0;
		$unitFound = false;

		foreach (static::getFlipCascadeFactors() as $source => $cascade) {
		    list($target, $factor) = $cascade;

		    if ($source === $realUnit) {
		        $unitFound = true;
		        $result += $this->$source;
		        $cumulativeFactor = 1;
		    }

		    if ($factor === false) {
		        if ($unitFound) {
		            break;
		        }

		        $result = 0;
		        $cumulativeFactor = 0;

		        continue;
		    }

		    if ($target === $realUnit) {
		        $unitFound = true;
		    }

		    if ($cumulativeFactor) {
		        $cumulativeFactor *= $factor;
		        $result += $this->$target * $cumulativeFactor;

		        continue;
		    }

		    $result = ($result + $this->$source) / $factor;
		}

		if (isset($target) && !$cumulativeFactor) {
		    $result += $this->$target;
		}

		if (!$unitFound) {
		    throw new InvalidArgumentException("Unit $unit have no configuration to get total from other units.");
		}

		if ($unit === 'weeks') {
		    return $result / static::getDaysPerWeek();
		}

		return $result;
	}
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----NzY1MjY1NzA1OTA2Nzg3OSAxMjY1NTQxODQwMjgzMjc4IDcwODY4NTEwODkzNTYxMzc=