<?php

declare (strict_types=1);
namespace VendorDuplicator\Cron;

use DateTimeInterface;
use DateTimeZone;
/**
 * Hours field.  Allows: * , / -.
 */
class HoursField extends AbstractField
{
    /**
     * {@inheritdoc}
     */
    protected $rangeStart = 0;
    /**
     * {@inheritdoc}
     */
    protected $rangeEnd = 23;
    /**
     * @var array|null Transitions returned by DateTimeZone::getTransitions()
     */
    protected $transitions = [];
    /**
     * @var int|null Timestamp of the start of the transitions range
     */
    protected $transitionsStart = null;
    /**
     * @var int|null Timestamp of the end of the transitions range
     */
    protected $transitionsEnd = null;
    /**
     * {@inheritdoc}
     */
    public function isSatisfiedBy(DateTimeInterface $date, $value, bool $invert): bool
    {
        $checkValue = (int) $date->format('H');
        $retval = $this->isSatisfied($checkValue, $value);
        if ($retval) {
            return $retval;
        }
        // Are we on the edge of a transition
        $lastTransition = $this->getPastTransition($date);
        if ($lastTransition !== null && $lastTransition["ts"] > (int) $date->format('U') - 3600) {
            $dtLastOffset = clone $date;
            $this->timezoneSafeModify($dtLastOffset, "-1 hour");
            $lastOffset = $dtLastOffset->getOffset();
            $dtNextOffset = clone $date;
            $this->timezoneSafeModify($dtNextOffset, "+1 hour");
            $nextOffset = $dtNextOffset->getOffset();
            $offsetChange = $nextOffset - $lastOffset;
            if ($offsetChange >= 3600) {
                $checkValue -= 1;
                return $this->isSatisfied($checkValue, $value);
            }
            if (!$invert && $offsetChange <= -3600) {
                $checkValue += 1;
                return $this->isSatisfied($checkValue, $value);
            }
        }
        return $retval;
    }
    public function getPastTransition(DateTimeInterface $date): ?array
    {
        $currentTimestamp = (int) $date->format('U');
        if ($this->transitions === null || $this->transitionsStart < $currentTimestamp + 86400 || $this->transitionsEnd > $currentTimestamp - 86400) {
            // We start a day before current time so we can differentiate between the first transition entry
            // and a change that happens now
            $dtLimitStart = clone $date;
            $dtLimitStart = $dtLimitStart->modify("-12 months");
            $dtLimitEnd = clone $date;
            $dtLimitEnd = $dtLimitEnd->modify('+12 months');
            $this->transitions = $date->getTimezone()->getTransitions($dtLimitStart->getTimestamp(), $dtLimitEnd->getTimestamp());
            if (empty($this->transitions)) {
                return null;
            }
            $this->transitionsStart = $dtLimitStart->getTimestamp();
            $this->transitionsEnd = $dtLimitEnd->getTimestamp();
        }
        $nextTransition = null;
        foreach ($this->transitions as $transition) {
            if ($transition["ts"] > $currentTimestamp) {
                continue;
            }
            if ($nextTransition !== null && $transition["ts"] < $nextTransition["ts"]) {
                continue;
            }
            $nextTransition = $transition;
        }
        return $nextTransition ?? null;
    }
    /**
     * {@inheritdoc}
     *
     * @param string|null                  $parts
     */
    public function increment(DateTimeInterface &$date, $invert = \false, $parts = null): FieldInterface
    {
        $originalTimestamp = (int) $date->format('U');
        // Change timezone to UTC temporarily. This will
        // allow us to go back or forwards and hour even
        // if DST will be changed between the hours.
        if (null === $parts || '*' === $parts) {
            if ($invert) {
                $date = $date->sub(new \DateInterval('PT1H'));
            } else {
                $date = $date->add(new \DateInterval('PT1H'));
            }
            $date = $this->setTimeHour($date, $invert, $originalTimestamp);
            return $this;
        }
        $parts = \false !== strpos($parts, ',') ? explode(',', $parts) : [$parts];
        $hours = [];
        foreach ($parts as $part) {
            $hours = array_merge($hours, $this->getRangeForExpression($part, 23));
        }
        $current_hour = (int) $date->format('H');
        $position = $invert ? \count($hours) - 1 : 0;
        $countHours = \count($hours);
        if ($countHours > 1) {
            for ($i = 0; $i < $countHours - 1; ++$i) {
                if (!$invert && $current_hour >= $hours[$i] && $current_hour < $hours[$i + 1] || $invert && $current_hour > $hours[$i] && $current_hour <= $hours[$i + 1]) {
                    $position = $invert ? $i : $i + 1;
                    break;
                }
            }
        }
        $target = (int) $hours[$position];
        $originalHour = (int) $date->format('H');
        $originalDay = (int) $date->format('d');
        $previousOffset = $date->getOffset();
        if (!$invert) {
            if ($originalHour >= $target) {
                $distance = 24 - $originalHour;
                $date = $this->timezoneSafeModify($date, "+{$distance} hours");
                $actualDay = (int) $date->format('d');
                $actualHour = (int) $date->format('H');
                if ($actualDay !== $originalDay + 1 && $actualHour !== 0) {
                    $offsetChange = $previousOffset - $date->getOffset();
                    $date = $this->timezoneSafeModify($date, "+{$offsetChange} seconds");
                }
                $originalHour = (int) $date->format('H');
            }
            $distance = $target - $originalHour;
            $date = $this->timezoneSafeModify($date, "+{$distance} hours");
        } else {
            if ($originalHour <= $target) {
                $distance = $originalHour + 1;
                $date = $this->timezoneSafeModify($date, "-" . $distance . " hours");
                $actualDay = (int) $date->format('d');
                $actualHour = (int) $date->format('H');
                if ($actualDay !== $originalDay - 1 && $actualHour !== 23) {
                    $offsetChange = $previousOffset - $date->getOffset();
                    $date = $this->timezoneSafeModify($date, "+{$offsetChange} seconds");
                }
                $originalHour = (int) $date->format('H');
            }
            $distance = $originalHour - $target;
            $date = $this->timezoneSafeModify($date, "-{$distance} hours");
        }
        $date = $this->setTimeHour($date, $invert, $originalTimestamp);
        $actualHour = (int) $date->format('H');
        if ($invert && ($actualHour === $target - 1 || $actualHour === 23 && $target === 0)) {
            $date = $this->timezoneSafeModify($date, "+1 hour");
        }
        return $this;
    }
}