<?php
declare(strict_types=1);
namespace Cron;
use DateTime;
use DateTimeImmutable;
use DateTimeInterface;
use DateTimeZone;
use Exception;
use InvalidArgumentException;
use RuntimeException;
use Webmozart\Assert\Assert;
/**
* CRON expression parser that can determine whether or not a CRON expression is
* due to run, the next run date and previous run date of a CRON expression.
* The determinations made by this class are accurate if checked run once per
* minute (seconds are dropped from date time comparisons).
*
* Schedule parts must map to:
* minute [0-59], hour [0-23], day of month, month [1-12|JAN-DEC], day of week
* [1-7|MON-SUN], and an optional year.
*
* @see http://en.wikipedia.org/wiki/Cron
*/
class CronExpression
{
public const MINUTE = 0;
public const HOUR = 1;
public const DAY = 2;
public const MONTH = 3;
public const WEEKDAY = 4;
/** @deprecated */
public const YEAR = 5;
public const MAPPINGS = [
'@yearly' => '0 0 1 1 *',
'@annually' => '0 0 1 1 *',
'@monthly' => '0 0 1 * *',
'@weekly' => '0 0 * * 0',
'@daily' => '0 0 * * *',
'@hourly' => '0 * * * *',
];
/**
* @var array CRON expression parts
*/
private $cronParts;
/**
* @var FieldFactoryInterface CRON field factory
*/
private $fieldFactory;
/**
* @var int Max iteration count when searching for next run date
*/
private $maxIterationCount = 1000;
/**
* @var array Order in which to test of cron parts
*/
private static $order = [
self::YEAR,
self::MONTH,
self::DAY,
self::WEEKDAY,
self::HOUR,
self::MINUTE,
];
/**
* @deprecated since version 3.0.2, use __construct instead.
*/
public static function factory(string $expression, FieldFactoryInterface $fieldFactory = null): CronExpression
{
/** @phpstan-ignore-next-line */
return new static($expression, $fieldFactory);
}
/**
* Validate a CronExpression.
*
* @param string $expression the CRON expression to validate
*
* @return bool True if a valid CRON expression was passed. False if not.
*/
public static function isValidExpression(string $expression): bool
{
try {
new CronExpression($expression);
} catch (InvalidArgumentException $e) {
return false;
}
return true;
}
/**
* Parse a CRON expression.
*
* @param string $expression CRON expression (e.g. '8 * * * *')
* @param null|FieldFactoryInterface $fieldFactory Factory to create cron fields
*/
public function __construct(string $expression, FieldFactoryInterface $fieldFactory = null)
{
$shortcut = strtolower($expression);
$expression = self::MAPPINGS[$shortcut] ?? $expression;
$this->fieldFactory = $fieldFactory ?: new FieldFactory();
$this->setExpression($expression);
}
/**
* Set or change the CRON expression.
*
* @param string $value CRON expression (e.g. 8 * * * *)
*
* @throws \InvalidArgumentException if not a valid CRON expression
*
* @return CronExpression
*/
public function setExpression(string $value): CronExpression
{
$split = preg_split('/\s/', $value, -1, PREG_SPLIT_NO_EMPTY);
Assert::isArray($split);
$this->cronParts = $split;
if (\count($this->cronParts) < 5) {
throw new InvalidArgumentException(
$value . ' is not a valid CRON expression'
);
}
foreach ($this->cronParts as $position => $part) {
$this->setPart($position, $part);
}
return $this;
}
/**
* Set part of the CRON expression.
*
* @param int $position The position of the CRON expression to set
* @param string $value The value to set
*
* @throws \InvalidArgumentException if the value is not valid for the part
*
* @return CronExpression
*/
public function setPart(int $position, string $value): CronExpression
{
if (!$this->fieldFactory->getField($position)->validate($value)) {
throw new InvalidArgumentException(
'Invalid CRON field value ' . $value . ' at position ' . $position
);
}
$this->cronParts[$position] = $value;
return $this;
}
/**
* Set max iteration count for searching next run dates.
*
* @param int $maxIterationCount Max iteration count when searching for next run date
*
* @return CronExpression
*/
public function setMaxIterationCount(int $maxIterationCount): CronExpression
{
$this->maxIterationCount = $maxIterationCount;
return $this;
}
/**
* Get a next run date relative to the current date or a specific date
*
* @param string|\DateTimeInterface $currentTime Relative calculation date
* @param int $nth Number of matches to skip before returning a
* matching next run date. 0, the default, will return the
* current date and time if the next run date falls on the
* current date and time. Setting this value to 1 will
* skip the first match and go to the second match.
* Setting this value to 2 will skip the first 2
* matches and so on.
* @param bool $allowCurrentDate Set to TRUE to return the current date if
* it matches the cron expression.
* @param null|string $timeZone TimeZone to use instead of the system default
*
* @throws \RuntimeException on too many iterations
* @throws \Exception
*
* @return \DateTime
*/
public function getNextRunDate($currentTime = 'now', int $nth = 0, bool $allowCurrentDate = false, $timeZone = null): DateTime
{
return $this->getRunDate($currentTime, $nth, false, $allowCurrentDate, $timeZone);
}
/**
* Get a previous run date relative to the current date or a specific date.
*
* @param string|\DateTimeInterface $currentTime Relative calculation date
* @param int $nth Number of matches to skip before returning
* @param bool $allowCurrentDate Set to TRUE to return the
* current date if it matches the cron expression
* @param null|string $timeZone TimeZone to use instead of the system default
*
* @throws \RuntimeException on too many iterations
* @throws \Exception
*
* @return \DateTime
*
* @see \Cron\CronExpression::getNextRunDate
*/
public function getPreviousRunDate($currentTime = 'now', int $nth = 0, bool $allowCurrentDate = false, $timeZone = null): DateTime
{
return $this->getRunDate($currentTime, $nth, true, $allowCurrentDate, $timeZone);
}
/**
* Get multiple run dates starting at the current date or a specific date.
*
* @param int $total Set the total number of dates to calculate
* @param string|\DateTimeInterface|null $currentTime Relative calculation date
* @param bool $invert Set to TRUE to retrieve previous dates
* @param bool $allowCurrentDate Set to TRUE to return the
* current date if it matches the cron expression
* @param null|string $timeZone TimeZone to use instead of the system default
*
* @return \DateTime[] Returns an array of run dates
*/
public function getMultipleRunDates(int $total, $currentTime = 'now', bool $invert = false, bool $allowCurrentDate = false, $timeZone = null): array
{
$matches = [];
$max = max(0, $total);
for ($i = 0; $i < $max; ++$i) {
try {
$matches[] = $this->getRunDate($currentTime, $i, $invert, $allowCurrentDate, $timeZone);
} catch (RuntimeException $e) {
break;
}
}
return $matches;
}
/**
* Get all or part of the CRON expression.
*
* @param int|string|null $part specify the part to retrieve or NULL to get the full
* cron schedule string
*
* @return null|string Returns the CRON expression, a part of the
* CRON expression, or NULL if the part was specified but not found
*/
public function getExpression($part = null): ?string
{
if (null === $part) {
return implode(' ', $this->cronParts);
}
if (array_key_exists($part, $this->cronParts)) {
return $this->cronParts[$part];
}
return null;
}
/**
* Gets the parts of the cron expression as an array.
*
* @return string[]
* The array of parts that make up this expression.
*/
public function getParts()
{
return $this->cronParts;
}
/**
* Helper method to output the full expression.
*
* @return string Full CRON expression
*/
public function __toString(): string
{
return (string) $this->getExpression();
}
/**
* Determine if the cron is due to run based on the current date or a
* specific date. This method assumes that the current number of
* seconds are irrelevant, and should be called once per minute.
*
* @param string|\DateTimeInterface $currentTime Relative calculation date
* @param null|string $timeZone TimeZone to use instead of the system default
*
* @return bool Returns TRUE if the cron is due to run or FALSE if not
*/
public function isDue($currentTime = 'now', $timeZone = null): bool
{
$timeZone = $this->determineTimeZone($currentTime, $timeZone);
if ('now' === $currentTime) {
$currentTime = new DateTime();
} elseif ($currentTime instanceof DateTime) {
$currentTime = clone $currentTime;
} elseif ($currentTime instanceof DateTimeImmutable) {
$currentTime = DateTime::createFromFormat('U', $currentTime->format('U'));
} elseif (\is_string($currentTime)) {
$currentTime = new DateTime($currentTime);
}
Assert::isInstanceOf($currentTime, DateTime::class);
$currentTime->setTimezone(new DateTimeZone($timeZone));
// drop the seconds to 0
$currentTime->setTime((int) $currentTime->format('H'), (int) $currentTime->format('i'), 0);
try {
return $this->getNextRunDate($currentTime, 0, true)->getTimestamp() === $currentTime->getTimestamp();
} catch (Exception $e) {
return false;
}
}
/**
* Get the next or previous run date of the expression relative to a date.
*
* @param string|\DateTimeInterface|null $currentTime Relative calculation date
* @param int $nth Number of matches to skip before returning
* @param bool $invert Set to TRUE to go backwards in time
* @param bool $allowCurrentDate Set to TRUE to return the
* current date if it matches the cron expression
* @param string|null $timeZone TimeZone to use instead of the system default
*
* @throws \RuntimeException on too many iterations
* @throws Exception
*
* @return \DateTime
*/
protected function getRunDate($currentTime = null, int $nth = 0, bool $invert = false, bool $allowCurrentDate = false, $timeZone = null): DateTime
{
$timeZone = $this->determineTimeZone($currentTime, $timeZone);
if ($currentTime instanceof DateTime) {
$currentDate = clone $currentTime;
} elseif ($currentTime instanceof DateTimeImmutable) {
$currentDate = DateTime::createFromFormat('U', $currentTime->format('U'));
} elseif (\is_string($currentTime)) {
$currentDate = new DateTime($currentTime);
} else {
$currentDate = new DateTime('now');
}
Assert::isInstanceOf($currentDate, DateTime::class);
$currentDate->setTimezone(new DateTimeZone($timeZone));
$currentDate->setTime((int) $currentDate->format('H'), (int) $currentDate->format('i'), 0);
$nextRun = clone $currentDate;
// We don't have to satisfy * or null fields
$parts = [];
$fields = [];
foreach (self::$order as $position) {
$part = $this->getExpression($position);
if (null === $part || '*' === $part) {
continue;
}
$parts[$position] = $part;
$fields[$position] = $this->fieldFactory->getField($position);
}
if (isset($parts[2]) && isset($parts[4])) {
$domExpression = sprintf('%s %s %s %s *', $this->getExpression(0), $this->getExpression(1), $this->getExpression(2), $this->getExpression(3));
$dowExpression = sprintf('%s %s * %s %s', $this->getExpression(0), $this->getExpression(1), $this->getExpression(3), $this->getExpression(4));
$domExpression = new self($domExpression);
$dowExpression = new self($dowExpression);
$domRunDates = $domExpression->getMultipleRunDates($nth + 1, $currentTime, $invert, $allowCurrentDate, $timeZone);
$dowRunDates = $dowExpression->getMultipleRunDates($nth + 1, $currentTime, $invert, $allowCurrentDate, $timeZone);
$combined = array_merge($domRunDates, $dowRunDates);
usort($combined, function ($a, $b) {
return $a->format('Y-m-d H:i:s') <=> $b->format('Y-m-d H:i:s');
});
return $combined[$nth];
}
// Set a hard limit to bail on an impossible date
for ($i = 0; $i < $this->maxIterationCount; ++$i) {
foreach ($parts as $position => $part) {
$satisfied = false;
// Get the field object used to validate this part
$field = $fields[$position];
// Check if this is singular or a list
if (false === strpos($part, ',')) {
$satisfied = $field->isSatisfiedBy($nextRun, $part);
} else {
foreach (array_map('trim', explode(',', $part)) as $listPart) {
if ($field->isSatisfiedBy($nextRun, $listPart)) {
$satisfied = true;
break;
}
}
}
// If the field is not satisfied, then start over
if (!$satisfied) {
$field->increment($nextRun, $invert, $part);
continue 2;
}
}
// Skip this match if needed
if ((!$allowCurrentDate && $nextRun == $currentDate) || --$nth > -1) {
$this->fieldFactory->getField(0)->increment($nextRun, $invert, $parts[0] ?? null);
continue;
}
return $nextRun;
}
// @codeCoverageIgnoreStart
throw new RuntimeException('Impossible CRON expression');
// @codeCoverageIgnoreEnd
}
/**
* Workout what timeZone should be used.
*
* @param string|\DateTimeInterface|null $currentTime Relative calculation date
* @param string|null $timeZone TimeZone to use instead of the system default
*
* @return string
*/
protected function determineTimeZone($currentTime, ?string $timeZone): string
{
if (null !== $timeZone) {
return $timeZone;
}
if ($currentTime instanceof DateTimeInterface) {
return $currentTime->getTimeZone()->getName();
}
return date_default_timezone_get();
}
}