daysIterator

<?php
declare(strict_types=1);

class daysIterator implements Iterator
{
    private int $daysOffset = 0;
    private ?DateInterval $dateInterval = null;
    private ?DateTimeImmutable $endDate = null;
    private ?DateTimeImmutable $startDate = null;


    public function current(): mixed
    {
        /*
         * Compute current date as number of days offset from start date.
         * 'invert' indicates whether a negative interval
         */
        $days = new DateInterval(sprintf('P%dD', $this->daysOffset));
        $date = $this->dateInterval->invert == 0 ? $this->startDate->add($days)
                                                 : $this->startDate->sub($days);

        /* reformat current date and return date fields as an integer array */
        $current = explode('/', $date->format('d/m/Y'));

        return ['day'   => (int) $current[0],
                'month' => (int) $current[1],
                'year'  => (int) $current[2],
               ];
    }


    public function key(): mixed
    {
        return $this->daysOffset;
    }


    public function next(): void
    {
        $this->daysOffset++;
    }


    public function rewind(): void
    {
        $this->daysOffset = 0;
    }


    public function valid(): bool
    {
        $this->dateInterval
        or throw new LogicException('Both start and end dates must be specified');

        return $this->daysOffset <= $this->dateInterval->days;
    }


    public function setEndDate(string $endDate)
    {
        $this->endDate = new DateTimeImmutable($endDate);

        $this->dateInterval();
    }


    public function setStartDate(string $startDate)
    {
        $this->startDate = new DateTimeImmutable($startDate);

        $this->dateInterval();
    }


    private function dateInterval()
    {
        if (
            ! is_null($this->startDate)
            && ! is_null($this->endDate)
        ) {
            /* determine interval between dates */
            $this->dateInterval = $this->startDate->diff($this->endDate);

            $this->daysOffset = 0;  // holds number of days from start date
        } else {
            $this->dateInterval = null;
        }
    }
}


$eol = empty($argc) ? '<br>' : PHP_EOL;  // determine end of line


$days = new daysIterator();
$days->setStartDate('2023-02-06');
$days->setEndDate('2023-02-01');

foreach ($days as $key => $current) {
    var_dump($key, $current);
    echo $eol;
}


/**************************************************************************************************/


class daysIterator_v2 implements Iterator
{
    private int $daysOffset;
    private DateInterval $dateInterval;
    private DateTimeImmutable $startDate;


    public function __construct(string $startDate, string $endDate)
    {
        $this->startDate = new DateTimeImmutable($startDate);

        /* determine interval between dates */
        $this->dateInterval = $this->startDate->diff(new DateTime($endDate));

        $this->daysOffset = 0;  // holds number of days from start date
    }


    public function current(): mixed
    {
        /*
         * Compute current date as number of days offset from start date.
         * 'invert' indicates whether a negative interval
         */
        $days = new DateInterval(sprintf('P%dD', $this->daysOffset));
        $date = $this->dateInterval->invert == 0 ? $this->startDate->add($days)
                                                 : $this->startDate->sub($days);

        /* reformat current date and return date fields as an integer array */
        $current = explode('/', $date->format('d/m/Y'));

        return ['day'   => (int) $current[0],
                'month' => (int) $current[1],
                'year'  => (int) $current[2],
               ];
    }


    public function key(): mixed
    {
        return $this->daysOffset;
    }


    public function next(): void
    {
        $this->daysOffset++;
    }


    public function rewind(): void
    {
        $this->daysOffset = 0;
    }


    public function valid(): bool
    {
        return $this->daysOffset <= $this->dateInterval->days;
    }
}


$eol = empty($argc) ? '<br>' : PHP_EOL;  // determine end of line


foreach (new daysIterator_v2('2023-02-06', '2023-02-20') as $key => $current) {
    var_dump($key, $current);
    echo $eol;
}