<?php

namespace Carbon;

use BadMethodCallException;
use Closure;
use Countable;
use DateInterval;
use DateTime;
use DateTimeInterface;
use InvalidArgumentException;
use Iterator;
use ReflectionClass;
use ReflectionFunction;
use ReflectionMethod;
use RuntimeException;

/**
 * Substitution of DatePeriod with some modifications and many more features.
 * Fully compatible with PHP 5.3+!
 *
 * @method static CarbonPeriod start($date, $inclusive = null) Create instance specifying start date.
 * @method static CarbonPeriod since($date, $inclusive = null) Alias for start().
 * @method static CarbonPeriod sinceNow($inclusive = null) Create instance with start date set to now.
 * @method static CarbonPeriod end($date = null, $inclusive = null) Create instance specifying end date.
 * @method static CarbonPeriod until($date = null, $inclusive = null) Alias for end().
 * @method static CarbonPeriod untilNow($inclusive = null) Create instance with end date set to now.
 * @method static CarbonPeriod dates($start, $end = null) Create instance with start and end date.
 * @method static CarbonPeriod between($start, $end = null) Create instance with start and end date.
 * @method static CarbonPeriod recurrences($recurrences = null) Create instance with maximum number of recurrences.
 * @method static CarbonPeriod times($recurrences = null) Alias for recurrences().
 * @method static CarbonPeriod options($options = null) Create instance with options.
 * @method static CarbonPeriod toggle($options, $state = null) Create instance with options toggled on or off.
 * @method static CarbonPeriod filter($callback, $name = null) Create instance with filter added to the stack.
 * @method static CarbonPeriod push($callback, $name = null) Alias for filter().
 * @method static CarbonPeriod prepend($callback, $name = null) Create instance with filter prepened to the stack.
 * @method static CarbonPeriod filters(array $filters) Create instance with filters stack.
 * @method static CarbonPeriod interval($interval) Create instance with given date interval.
 * @method static CarbonPeriod each($interval) Create instance with given date interval.
 * @method static CarbonPeriod every($interval) Create instance with given date interval.
 * @method static CarbonPeriod step($interval) Create instance with given date interval.
 * @method static CarbonPeriod stepBy($interval) Create instance with given date interval.
 * @method static CarbonPeriod invert() Create instance with inverted date interval.
 * @method static CarbonPeriod years($years = 1) Create instance specifying a number of years for date interval.
 * @method static CarbonPeriod year($years = 1) Alias for years().
 * @method static CarbonPeriod months($months = 1) Create instance specifying a number of months for date interval.
 * @method static CarbonPeriod month($months = 1) Alias for months().
 * @method static CarbonPeriod weeks($weeks = 1) Create instance specifying a number of weeks for date interval.
 * @method static CarbonPeriod week($weeks = 1) Alias for weeks().
 * @method static CarbonPeriod days($days = 1) Create instance specifying a number of days for date interval.
 * @method static CarbonPeriod dayz($days = 1) Alias for days().
 * @method static CarbonPeriod day($days = 1) Alias for days().
 * @method static CarbonPeriod hours($hours = 1) Create instance specifying a number of hours for date interval.
 * @method static CarbonPeriod hour($hours = 1) Alias for hours().
 * @method static CarbonPeriod minutes($minutes = 1) Create instance specifying a number of minutes for date interval.
 * @method static CarbonPeriod minute($minutes = 1) Alias for minutes().
 * @method static CarbonPeriod seconds($seconds = 1) Create instance specifying a number of seconds for date interval.
 * @method static CarbonPeriod second($seconds = 1) Alias for seconds().
 * @method CarbonPeriod start($date, $inclusive = null) Change the period start date.
 * @method CarbonPeriod since($date, $inclusive = null) Alias for start().
 * @method CarbonPeriod sinceNow($inclusive = null) Change the period start date to now.
 * @method CarbonPeriod end($date = null, $inclusive = null) Change the period end date.
 * @method CarbonPeriod until($date = null, $inclusive = null) Alias for end().
 * @method CarbonPeriod untilNow($inclusive = null) Change the period end date to now.
 * @method CarbonPeriod dates($start, $end = null) Change the period start and end date.
 * @method CarbonPeriod recurrences($recurrences = null) Change the maximum number of recurrences.
 * @method CarbonPeriod times($recurrences = null) Alias for recurrences().
 * @method CarbonPeriod options($options = null) Change the period options.
 * @method CarbonPeriod toggle($options, $state = null) Toggle given options on or off.
 * @method CarbonPeriod filter($callback, $name = null) Add a filter to the stack.
 * @method CarbonPeriod push($callback, $name = null) Alias for filter().
 * @method CarbonPeriod prepend($callback, $name = null) Prepend a filter to the stack.
 * @method CarbonPeriod filters(array $filters = array()) Set filters stack.
 * @method CarbonPeriod interval($interval) Change the period date interval.
 * @method CarbonPeriod invert() Invert the period date interval.
 * @method CarbonPeriod years($years = 1) Set the years portion of the date interval.
 * @method CarbonPeriod year($years = 1) Alias for years().
 * @method CarbonPeriod months($months = 1) Set the months portion of the date interval.
 * @method CarbonPeriod month($months = 1) Alias for months().
 * @method CarbonPeriod weeks($weeks = 1) Set the weeks portion of the date interval.
 * @method CarbonPeriod week($weeks = 1) Alias for weeks().
 * @method CarbonPeriod days($days = 1) Set the days portion of the date interval.
 * @method CarbonPeriod dayz($days = 1) Alias for days().
 * @method CarbonPeriod day($days = 1) Alias for days().
 * @method CarbonPeriod hours($hours = 1) Set the hours portion of the date interval.
 * @method CarbonPeriod hour($hours = 1) Alias for hours().
 * @method CarbonPeriod minutes($minutes = 1) Set the minutes portion of the date interval.
 * @method CarbonPeriod minute($minutes = 1) Alias for minutes().
 * @method CarbonPeriod seconds($seconds = 1) Set the seconds portion of the date interval.
 * @method CarbonPeriod second($seconds = 1) Alias for seconds().
 */
class CarbonPeriod implements Iterator, Countable
{
	/**
	 * Built-in filters.
	 *
	 * @var string
	 */
	const RECURRENCES_FILTER = 'Carbon\CarbonPeriod::filterRecurrences';
	const END_DATE_FILTER = 'Carbon\CarbonPeriod::filterEndDate';

	/**
	 * Special value which can be returned by filters to end iteration. Also a filter.
	 *
	 * @var string
	 */
	const END_ITERATION = 'Carbon\CarbonPeriod::endIteration';

	/**
	 * Available options.
	 *
	 * @var int
	 */
	const EXCLUDE_START_DATE = 1;
	const EXCLUDE_END_DATE = 2;

	/**
	 * Number of maximum attempts before giving up on finding next valid date.
	 *
	 * @var int
	 */
	const NEXT_MAX_ATTEMPTS = 1000;

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

	/**
	 * Underlying date interval instance. Always present, one day by default.
	 *
	 * @var CarbonInterval
	 */
	protected $dateInterval;

	/**
	 * Whether current date interval was set by default.
	 *
	 * @var bool
	 */
	protected $isDefaultInterval;

	/**
	 * The filters stack.
	 *
	 * @var array
	 */
	protected $filters = array();

	/**
	 * Period start date. Applied on rewind. Always present, now by default.
	 *
	 * @var Carbon
	 */
	protected $startDate;

	/**
	 * Period end date. For inverted interval should be before the start date. Applied via a filter.
	 *
	 * @var Carbon|null
	 */
	protected $endDate;

	/**
	 * Limit for number of recurrences. Applied via a filter.
	 *
	 * @var int|null
	 */
	protected $recurrences;

	/**
	 * Iteration options.
	 *
	 * @var int
	 */
	protected $options;

	/**
	 * Index of current date. Always sequential, even if some dates are skipped by filters.
	 * Equal to null only before the first iteration.
	 *
	 * @var int
	 */
	protected $key;

	/**
	 * Current date. May temporarily hold unaccepted value when looking for a next valid date.
	 * Equal to null only before the first iteration.
	 *
	 * @var Carbon
	 */
	protected $current;

	/**
	 * Timezone of current date. Taken from the start date.
	 *
	 * @var \DateTimeZone|null
	 */
	protected $timezone;

	/**
	 * The cached validation result for current date.
	 *
	 * @var bool|string|null
	 */
	protected $validationResult;


	/**
	 * Create a new instance.
	 *
	 * @return static
	 */
	public static function create()
	{
		return static::createFromArray(func_get_args());
	}


	/**
	 * Create a new instance from an array of parameters.
	 *
	 * @param array $params
	 *
	 * @return static
	 */
	public static function createFromArray(array $params)
	{
		$reflection = new ReflectionClass(get_class());
		/** @var static $instance */
		$instance = $reflection->newInstanceArgs($params);

		return $instance;
	}


	/**
	 * Create CarbonPeriod from ISO 8601 string.
	 *
	 * @param string   $iso
	 * @param int|null $options
	 *
	 * @return static
	 */
	public static function createFromIso($iso, $options = null)
	{
		$params = static::parseIso8601($iso);

		$instance = static::createFromArray($params);

		if ($options !== null) {
		    $instance->setOptions($options);
		}

		return $instance;
	}


	/**
	 * Return whether given interval contains non zero value of any time unit.
	 *
	 * @param \DateInterval $interval
	 *
	 * @return bool
	 */
	protected static function intervalHasTime(DateInterval $interval)
	{
		return $interval->h || $interval->i || $interval->s || array_key_exists('f', get_object_vars($interval)) && $interval->f;
	}


	/**
	 * Return whether given callable is a string pointing to one of Carbon's is* methods
	 * and should be automatically converted to a filter callback.
	 *
	 * @param callable $callable
	 *
	 * @return bool
	 */
	protected static function isCarbonPredicateMethod($callable)
	{
		return is_string($callable) && substr($callable, 0, 2) === 'is' && (method_exists('Carbon\Carbon', $callable) || Carbon::hasMacro($callable));
	}


	/**
	 * Return whether given variable is an ISO 8601 specification.
	 *
	 * Note: Check is very basic, as actual validation will be done later when parsing.
	 * We just want to ensure that variable is not any other type of a valid parameter.
	 *
	 * @param mixed $var
	 *
	 * @return bool
	 */
	protected static function isIso8601($var)
	{
		if (!is_string($var)) {
		    return false;
		}

		// Match slash but not within a timezone name.
		$part = '[a-z]+(?:[_-][a-z]+)*';

		preg_match("#\b$part/$part\b|(/)#i", $var, $match);

		return isset($match[1]);
	}


	/**
	 * Parse given ISO 8601 string into an array of arguments.
	 *
	 * @param string $iso
	 *
	 * @return array
	 */
	protected static function parseIso8601($iso)
	{
		$result = array();

		$interval = null;
		$start = null;
		$end = null;

		foreach (explode('/', $iso) as $key => $part) {
		    if ($key === 0 && preg_match('/^R([0-9]*)$/', $part, $match)) {
		        $parsed = strlen($match[1]) ? (int) $match[1] : null;
		    } elseif ($interval === null && $parsed = CarbonInterval::make($part)) {
		        $interval = $part;
		    } elseif ($start === null && $parsed = Carbon::make($part)) {
		        $start = $part;
		    } elseif ($end === null && $parsed = Carbon::make(static::addMissingParts($start, $part))) {
		        $end = $part;
		    } else {
		        throw new InvalidArgumentException("Invalid ISO 8601 specification: $iso.");
		    }

		    $result[] = $parsed;
		}

		return $result;
	}


	/**
	 * Add missing parts of the target date from the soure date.
	 *
	 * @param string $source
	 * @param string $target
	 *
	 * @return string
	 */
	protected static function addMissingParts($source, $target)
	{
		$pattern = '/'.preg_replace('/[0-9]+/', '[0-9]+', preg_quote($target, '/')).'$/';

		$result = preg_replace($pattern, $target, $source, 1, $count);

		return $count ? $result : $target;
	}


	/**
	 * 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]);
	}


	/**
	 * Provide static proxy for instance aliases.
	 *
	 * @param string $method
	 * @param array  $parameters
	 *
	 * @return mixed
	 */
	public static function __callStatic($method, $parameters)
	{
		return call_user_func_array(
		    array(new static, $method), $parameters
		);
	}


	/**
	 * CarbonPeriod constructor.
	 *
	 * @throws InvalidArgumentException
	 */
	public function __construct()
	{
		$arguments = func_get_args();

		if (count($arguments) && static::isIso8601($iso = $arguments[0])) {
		    array_splice($arguments, 0, 1, static::parseIso8601($iso));
		}

		foreach ($arguments as $argument) {
		    if ($this->dateInterval === null && $parsed = CarbonInterval::make($argument)) {
		        $this->setDateInterval($parsed);
		    } elseif ($this->startDate === null && $parsed = Carbon::make($argument)) {
		        $this->setStartDate($parsed);
		    } elseif ($this->endDate === null && $parsed = Carbon::make($argument)) {
		        $this->setEndDate($parsed);
		    } elseif ($this->recurrences === null && $this->endDate === null && is_numeric($argument)) {
		        $this->setRecurrences($argument);
		    } elseif ($this->options === null && (is_int($argument) || $argument === null)) {
		        $this->setOptions($argument);
		    } else {
		        throw new InvalidArgumentException('Invalid constructor parameters.');
		    }
		}

		if ($this->startDate === null) {
		    $this->setStartDate(Carbon::now());
		}

		if ($this->dateInterval === null) {
		    $this->setDateInterval(CarbonInterval::day());

		    $this->isDefaultInterval = true;
		}

		if ($this->options === null) {
		    $this->setOptions(0);
		}
	}


	/**
	 * Change the period date interval.
	 *
	 * @param DateInterval|string $interval
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return $this
	 */
	public function setDateInterval($interval)
	{
		if (!$interval = CarbonInterval::make($interval)) {
		    throw new InvalidArgumentException('Invalid interval.');
		}

		if ($interval->spec() === 'PT0S') {
		    throw new InvalidArgumentException('Empty interval is not accepted.');
		}

		$this->dateInterval = $interval;

		$this->isDefaultInterval = false;

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Invert the period date interval.
	 *
	 * @return $this
	 */
	public function invertDateInterval()
	{
		$interval = $this->dateInterval->invert();

		return $this->setDateInterval($interval);
	}


	/**
	 * Set start and end date.
	 *
	 * @param DateTime|DateTimeInterface|string      $start
	 * @param DateTime|DateTimeInterface|string|null $end
	 *
	 * @return $this
	 */
	public function setDates($start, $end)
	{
		$this->setStartDate($start);
		$this->setEndDate($end);

		return $this;
	}


	/**
	 * Change the period options.
	 *
	 * @param int|null $options
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return $this
	 */
	public function setOptions($options)
	{
		if (!is_int($options) && !is_null($options)) {
		    throw new InvalidArgumentException('Invalid options.');
		}

		$this->options = $options ?: 0;

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Get the period options.
	 *
	 * @return int
	 */
	public function getOptions()
	{
		return $this->options;
	}


	/**
	 * Toggle given options on or off.
	 *
	 * @param int       $options
	 * @param bool|null $state
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return $this
	 */
	public function toggleOptions($options, $state = null)
	{
		if ($state === null) {
		    $state = ($this->options & $options) !== $options;
		}

		return $this->setOptions($state ?
		    $this->options | $options :
		    $this->options & ~$options
		);
	}


	/**
	 * Toggle EXCLUDE_START_DATE option.
	 *
	 * @param bool $state
	 *
	 * @return $this
	 */
	public function excludeStartDate($state = true)
	{
		return $this->toggleOptions(static::EXCLUDE_START_DATE, $state);
	}


	/**
	 * Toggle EXCLUDE_END_DATE option.
	 *
	 * @param bool $state
	 *
	 * @return $this
	 */
	public function excludeEndDate($state = true)
	{
		return $this->toggleOptions(static::EXCLUDE_END_DATE, $state);
	}


	/**
	 * Get the underlying date interval.
	 *
	 * @return CarbonInterval
	 */
	public function getDateInterval()
	{
		return $this->dateInterval->copy();
	}


	/**
	 * Get start date of the period.
	 *
	 * @return Carbon
	 */
	public function getStartDate()
	{
		return $this->startDate->copy();
	}


	/**
	 * Get end date of the period.
	 *
	 * @return Carbon|null
	 */
	public function getEndDate()
	{
		if ($this->endDate) {
		    return $this->endDate->copy();
		}
	}


	/**
	 * Get number of recurrences.
	 *
	 * @return int|null
	 */
	public function getRecurrences()
	{
		return $this->recurrences;
	}


	/**
	 * Returns true if the start date should be excluded.
	 *
	 * @return bool
	 */
	public function isStartExcluded()
	{
		return ($this->options & static::EXCLUDE_START_DATE) !== 0;
	}


	/**
	 * Returns true if the end date should be excluded.
	 *
	 * @return bool
	 */
	public function isEndExcluded()
	{
		return ($this->options & static::EXCLUDE_END_DATE) !== 0;
	}


	/**
	 * Add a filter to the stack.
	 *
	 * @param callable $callback
	 * @param string   $name
	 *
	 * @return $this
	 */
	public function addFilter($callback, $name = null)
	{
		$tuple = $this->createFilterTuple(func_get_args());

		$this->filters[] = $tuple;

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Prepend a filter to the stack.
	 *
	 * @param callable $callback
	 * @param string   $name
	 *
	 * @return $this
	 */
	public function prependFilter($callback, $name = null)
	{
		$tuple = $this->createFilterTuple(func_get_args());

		array_unshift($this->filters, $tuple);

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Create a filter tuple from raw parameters.
	 *
	 * Will create an automatic filter callback for one of Carbon's is* methods.
	 *
	 * @param array $parameters
	 *
	 * @return array
	 */
	protected function createFilterTuple(array $parameters)
	{
		$method = array_shift($parameters);

		if (!$this->isCarbonPredicateMethod($method)) {
		    return array($method, array_shift($parameters));
		}

		return array(function ($date) use ($method, $parameters) {
		    return call_user_func_array(array($date, $method), $parameters);
		}, $method);
	}


	/**
	 * Remove a filter by instance or name.
	 *
	 * @param callable|string $filter
	 *
	 * @return $this
	 */
	public function removeFilter($filter)
	{
		$key = is_callable($filter) ? 0 : 1;

		$this->filters = array_values(array_filter(
		    $this->filters,
		    function ($tuple) use ($key, $filter) {
		        return $tuple[$key] !== $filter;
		    }
		));

		$this->updateInternalState();

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Return whether given instance or name is in the filter stack.
	 *
	 * @param callable|string $filter
	 *
	 * @return bool
	 */
	public function hasFilter($filter)
	{
		$key = is_callable($filter) ? 0 : 1;

		foreach ($this->filters as $tuple) {
		    if ($tuple[$key] === $filter) {
		        return true;
		    }
		}

		return false;
	}


	/**
	 * Get filters stack.
	 *
	 * @return array
	 */
	public function getFilters()
	{
		return $this->filters;
	}


	/**
	 * Set filters stack.
	 *
	 * @param array $filters
	 *
	 * @return $this
	 */
	public function setFilters(array $filters)
	{
		$this->filters = $filters;

		$this->updateInternalState();

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Reset filters stack.
	 *
	 * @return $this
	 */
	public function resetFilters()
	{
		$this->filters = array();

		if ($this->endDate !== null) {
		    $this->filters[] = array(static::END_DATE_FILTER, null);
		}

		if ($this->recurrences !== null) {
		    $this->filters[] = array(static::RECURRENCES_FILTER, null);
		}

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Update properties after removing built-in filters.
	 *
	 * @return void
	 */
	protected function updateInternalState()
	{
		if (!$this->hasFilter(static::END_DATE_FILTER)) {
		    $this->endDate = null;
		}

		if (!$this->hasFilter(static::RECURRENCES_FILTER)) {
		    $this->recurrences = null;
		}
	}


	/**
	 * Add a recurrences filter (set maximum number of recurrences).
	 *
	 * @param int|null $recurrences
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return $this
	 */
	public function setRecurrences($recurrences)
	{
		if (!is_numeric($recurrences) && !is_null($recurrences) || $recurrences < 0) {
		    throw new InvalidArgumentException('Invalid number of recurrences.');
		}

		if ($recurrences === null) {
		    return $this->removeFilter(static::RECURRENCES_FILTER);
		}

		$this->recurrences = (int) $recurrences;

		if (!$this->hasFilter(static::RECURRENCES_FILTER)) {
		    return $this->addFilter(static::RECURRENCES_FILTER);
		}

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * Recurrences filter callback (limits number of recurrences).
	 *
	 * @param \Carbon\Carbon $current
	 * @param int            $key
	 *
	 * @return bool|string
	 */
	protected function filterRecurrences($current, $key)
	{
		if ($key < $this->recurrences) {
		    return true;
		}

		return static::END_ITERATION;
	}


	/**
	 * Change the period start date.
	 *
	 * @param DateTime|DateTimeInterface|string $date
	 * @param bool|null                         $inclusive
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return $this
	 */
	public function setStartDate($date, $inclusive = null)
	{
		if (!$date = Carbon::make($date)) {
		    throw new InvalidArgumentException('Invalid start date.');
		}

		$this->startDate = $date;

		if ($inclusive !== null) {
		    $this->toggleOptions(static::EXCLUDE_START_DATE, !$inclusive);
		}

		return $this;
	}


	/**
	 * Change the period end date.
	 *
	 * @param DateTime|DateTimeInterface|string|null $date
	 * @param bool|null                              $inclusive
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return $this
	 */
	public function setEndDate($date, $inclusive = null)
	{
		if (!is_null($date) && !$date = Carbon::make($date)) {
		    throw new InvalidArgumentException('Invalid end date.');
		}

		if (!$date) {
		    return $this->removeFilter(static::END_DATE_FILTER);
		}

		$this->endDate = $date;

		if ($inclusive !== null) {
		    $this->toggleOptions(static::EXCLUDE_END_DATE, !$inclusive);
		}

		if (!$this->hasFilter(static::END_DATE_FILTER)) {
		    return $this->addFilter(static::END_DATE_FILTER);
		}

		$this->handleChangedParameters();

		return $this;
	}


	/**
	 * End date filter callback.
	 *
	 * @param \Carbon\Carbon $current
	 *
	 * @return bool|string
	 */
	protected function filterEndDate($current)
	{
		if (!$this->isEndExcluded() && $current == $this->endDate) {
		    return true;
		}

		if ($this->dateInterval->invert ? $current > $this->endDate : $current < $this->endDate) {
		    return true;
		}

		return static::END_ITERATION;
	}


	/**
	 * End iteration filter callback.
	 *
	 * @return string
	 */
	protected function endIteration()
	{
		return static::END_ITERATION;
	}


	/**
	 * Handle change of the parameters.
	 */
	protected function handleChangedParameters()
	{
		$this->validationResult = null;
	}


	/**
	 * Validate current date and stop iteration when necessary.
	 *
	 * Returns true when current date is valid, false if it is not, or static::END_ITERATION
	 * when iteration should be stopped.
	 *
	 * @return bool|string
	 */
	protected function validateCurrentDate()
	{
		if ($this->current === null) {
		    $this->rewind();
		}

		// Check after the first rewind to avoid repeating the initial validation.
		if ($this->validationResult !== null) {
		    return $this->validationResult;
		}

		return $this->validationResult = $this->checkFilters();
	}


	/**
	 * Check whether current value and key pass all the filters.
	 *
	 * @return bool|string
	 */
	protected function checkFilters()
	{
		$current = $this->prepareForReturn($this->current);

		foreach ($this->filters as $tuple) {
		    $result = call_user_func(
		        $tuple[0], $current->copy(), $this->key, $this
		    );

		    if ($result === static::END_ITERATION) {
		        return static::END_ITERATION;
		    }

		    if (!$result) {
		        return false;
		    }
		}

		return true;
	}


	/**
	 * Prepare given date to be returned to the external logic.
	 *
	 * @param Carbon $date
	 *
	 * @return Carbon
	 */
	protected function prepareForReturn(Carbon $date)
	{
		$date = $date->copy();

		if ($this->timezone) {
		    $date->setTimezone($this->timezone);
		}

		return $date;
	}


	/**
	 * Check if the current position is valid.
	 *
	 * @return bool
	 */
	public function valid()
	{
		return $this->validateCurrentDate() === true;
	}


	/**
	 * Return the current key.
	 *
	 * @return int|null
	 */
	public function key()
	{
		if ($this->valid()) {
		    return $this->key;
		}
	}


	/**
	 * Return the current date.
	 *
	 * @return Carbon|null
	 */
	public function current()
	{
		if ($this->valid()) {
		    return $this->prepareForReturn($this->current);
		}
	}


	/**
	 * Move forward to the next date.
	 *
	 * @throws \RuntimeException
	 *
	 * @return void
	 */
	public function next()
	{
		if ($this->current === null) {
		    $this->rewind();
		}

		if ($this->validationResult !== static::END_ITERATION) {
		    $this->key++;

		    $this->incrementCurrentDateUntilValid();
		}
	}


	/**
	 * Rewind to the start date.
	 *
	 * Iterating over a date in the UTC timezone avoids bug during backward DST change.
	 *
	 * @see https://bugs.php.net/bug.php?id=72255
	 * @see https://bugs.php.net/bug.php?id=74274
	 * @see https://wiki.php.net/rfc/datetime_and_daylight_saving_time
	 *
	 * @throws \RuntimeException
	 *
	 * @return void
	 */
	public function rewind()
	{
		$this->key = 0;
		$this->current = $this->startDate->copy();
		$this->timezone = static::intervalHasTime($this->dateInterval) ? $this->current->getTimezone() : null;

		if ($this->timezone) {
		    $this->current->setTimezone('UTC');
		}

		$this->validationResult = null;

		if ($this->isStartExcluded() || $this->validateCurrentDate() === false) {
		    $this->incrementCurrentDateUntilValid();
		}
	}


	/**
	 * Skip iterations and returns iteration state (false if ended, true if still valid).
	 *
	 * @param int $count steps number to skip (1 by default)
	 *
	 * @return bool
	 */
	public function skip($count = 1)
	{
		for ($i = $count; $this->valid() && $i > 0; $i--) {
		    $this->next();
		}

		return $this->valid();
	}


	/**
	 * Keep incrementing the current date until a valid date is found or the iteration is ended.
	 *
	 * @throws \RuntimeException
	 *
	 * @return void
	 */
	protected function incrementCurrentDateUntilValid()
	{
		$attempts = 0;

		do {
		    $this->current->add($this->dateInterval);

		    $this->validationResult = null;

		    if (++$attempts > static::NEXT_MAX_ATTEMPTS) {
		        throw new RuntimeException('Could not find next valid date.');
		    }
		} while ($this->validateCurrentDate() === false);
	}


	/**
	 * Format the date period as ISO 8601.
	 *
	 * @return string
	 */
	public function toIso8601String()
	{
		$parts = array();

		if ($this->recurrences !== null) {
		    $parts[] = 'R'.$this->recurrences;
		}

		$parts[] = $this->startDate->toIso8601String();

		$parts[] = $this->dateInterval->spec();

		if ($this->endDate !== null) {
		    $parts[] = $this->endDate->toIso8601String();
		}

		return implode('/', $parts);
	}


	/**
	 * Convert the date period into a string.
	 *
	 * @return string
	 */
	public function toString()
	{
		$translator = Carbon::getTranslator();

		$parts = array();

		$format = !$this->startDate->isStartOfDay() || $this->endDate && !$this->endDate->isStartOfDay()
		    ? 'Y-m-d H:i:s'
		    : 'Y-m-d';

		if ($this->recurrences !== null) {
		    $parts[] = $translator->transChoice('period_recurrences', $this->recurrences, array(':count' => $this->recurrences));
		}

		$parts[] = $translator->trans('period_interval', array(':interval' => $this->dateInterval->forHumans()));

		$parts[] = $translator->trans('period_start_date', array(':date' => $this->startDate->format($format)));

		if ($this->endDate !== null) {
		    $parts[] = $translator->trans('period_end_date', array(':date' => $this->endDate->format($format)));
		}

		$result = implode(' ', $parts);

		return mb_strtoupper(mb_substr($result, 0, 1)).mb_substr($result, 1);
	}


	/**
	 * Format the date period as ISO 8601.
	 *
	 * @return string
	 */
	public function spec()
	{
		return $this->toIso8601String();
	}


	/**
	 * Convert the date period into an array without changing current iteration state.
	 *
	 * @return array
	 */
	public function toArray()
	{
		$state = array(
		    $this->key,
		    $this->current ? $this->current->copy() : null,
		    $this->validationResult,
		);

		$result = iterator_to_array($this);

		list(
		    $this->key,
		    $this->current,
		    $this->validationResult
		) = $state;

		return $result;
	}


	/**
	 * Count dates in the date period.
	 *
	 * @return int
	 */
	public function count()
	{
		return count($this->toArray());
	}


	/**
	 * Return the first date in the date period.
	 *
	 * @return Carbon|null
	 */
	public function first()
	{
		if ($array = $this->toArray()) {
		    return $array[0];
		}
	}


	/**
	 * Return the last date in the date period.
	 *
	 * @return Carbon|null
	 */
	public function last()
	{
		if ($array = $this->toArray()) {
		    return $array[count($array) - 1];
		}
	}


	/**
	 * 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);
	}


	/**
	 * Convert the date period into a string.
	 *
	 * @return string
	 */
	public function __toString()
	{
		return $this->toString();
	}


	/**
	 * Add aliases for setters.
	 *
	 * CarbonPeriod::days(3)->hours(5)->invert()
	 *     ->sinceNow()->until('2010-01-10')
	 *     ->filter(...)
	 *     ->count()
	 *
	 * Note: We use magic method to let static and instance aliases with the same names.
	 *
	 * @param string $method
	 * @param array  $parameters
	 *
	 * @return mixed
	 */
	public function __call($method, $parameters)
	{
		if (static::hasMacro($method)) {
		    return $this->callMacro($method, $parameters);
		}

		$first = count($parameters) >= 1 ? $parameters[0] : null;
		$second = count($parameters) >= 2 ? $parameters[1] : null;

		switch ($method) {
		    case 'start':
		    case 'since':
		        return $this->setStartDate($first, $second);

		    case 'sinceNow':
		        return $this->setStartDate(new Carbon, $first);

		    case 'end':
		    case 'until':
		        return $this->setEndDate($first, $second);

		    case 'untilNow':
		        return $this->setEndDate(new Carbon, $first);

		    case 'dates':
		    case 'between':
		        return $this->setDates($first, $second);

		    case 'recurrences':
		    case 'times':
		        return $this->setRecurrences($first);

		    case 'options':
		        return $this->setOptions($first);

		    case 'toggle':
		        return $this->toggleOptions($first, $second);

		    case 'filter':
		    case 'push':
		        return $this->addFilter($first, $second);

		    case 'prepend':
		        return $this->prependFilter($first, $second);

		    case 'filters':
		        return $this->setFilters($first ?: array());

		    case 'interval':
		    case 'each':
		    case 'every':
		    case 'step':
		    case 'stepBy':
		        return $this->setDateInterval($first);

		    case 'invert':
		        return $this->invertDateInterval();

		    case 'years':
		    case 'year':
		    case 'months':
		    case 'month':
		    case 'weeks':
		    case 'week':
		    case 'days':
		    case 'dayz':
		    case 'day':
		    case 'hours':
		    case 'hour':
		    case 'minutes':
		    case 'minute':
		    case 'seconds':
		    case 'second':
		        return $this->setDateInterval(call_user_func(
		            // Override default P1D when instantiating via fluent setters.
		            array($this->isDefaultInterval ? new CarbonInterval('PT0S') : $this->dateInterval, $method),
		            count($parameters) === 0 ? 1 : $first
		        ));
		}

		throw new BadMethodCallException("Method $method does not exist.");
	}
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----MTIxOTk0MTY4MjY5MjcwOCA4OTE5MzgwMTA3OTE2MzQ4IDU5MDAwNTEyMzgyMDM1ODU=