journal-intime/app/Models/Calendar/Month.php

<?php

namespace App\Models\Calendar;

use App\Post;
use DateInterval;
use DatePeriod;
use DateTime;
use Illuminate\Database\Eloquent\Collection;

class Month
{
    /** @var int|string */
    protected $year;

    /** @var int|string */
    protected $month;

    /** @var Day[] */
    protected $days = [];

    /**
     * Month constructor.
     * @param int|string $year
     * @param int|string $month
     * @param array $posts
     * @throws \Exception
     */
    public function __construct($year, $month, $posts = [])
    {
        $this->year = $year;
        $this->month = $month;
        $this->fillDays($posts);
    }

    /**
     * @param $posts
     * @throws \Exception
     */
    protected function fillDays($posts)
    {
        $start = DateTime::createFromFormat('Y-m-d', sprintf('%s-%s-01', $this->year, str_pad($this->month, '0', 2)));
        $interval = new DateInterval('P1D');
        $end = clone $start;
        $end->add(new DateInterval('P1M'));
        $period = new DatePeriod($start, $interval, $end);

        foreach ($period as $dt) {
            $post = null;
            if (count($posts) > 0 && $posts->first()->date_post->format('Ymd') === $dt->format('Ymd')) {
                $post = $posts->shift();
            }

            $this->days[] = new Day($dt, $post);
        }
    }

    /**
     * @return string
     */
    public function getDate()
    {
        return DateTime::createFromFormat('Y-m-d', sprintf('%s-%s-01', $this->year, str_pad($this->month, '0', 2)))
            ->format('F Y');
    }

    /**
     * @return Day[]
     */
    public function getDays(): array
    {
        return $this->days;
    }

    /**
     * @return DateTime|false
     */
    public function getPrevious()
    {
        return DateTime::createFromFormat('Y-m-d', sprintf('%s-%s-01', $this->year, str_pad($this->month, '0', 2)))
            ->modify('-1 month');
    }

    /**
     * @return DateTime|false
     */
    public function getNext()
    {
        return DateTime::createFromFormat('Y-m-d', sprintf('%s-%s-01', $this->year, str_pad($this->month, '0', 2)))
            ->modify('+1 month');
    }

    /**
     * @return string
     */
    public function render(): string
    {
        $content = '<ul class="dates">';

        $first_day_of_month = DateTime::createFromFormat('Y-m-d', sprintf('%s-%s-01', $this->year, $this->month))->format('N');
        for ($i = 1; $i < $first_day_of_month; $i++) {
            $content .= '<li></li>';
        }
        foreach ($this->days as $day) {
            $content .= $this->_showDay($day);
        }
        $content .= '</ul>';

        return $content;
    }

    /**
     * @param Day $day
     * @return string
     */
    private function _showDay(Day $day): string
    {
        $currentDate = $day->getDate()->format('Ymd');
        $day_of_week = $day->getDate()->format('N');
        $day_number = $day->getDate()->format('d');
        $post = $day->getPost();
        $classes = ['day'];
        if ($currentDate === date('Ymd')) {
            $classes[] = 'today';
        }
        if ($day_of_week % 7 === 1) {
            $classes[] = 'start';
        }
        if ($day_of_week % 7 === 0) {
            $classes[] = 'end';
        }
        if ($post instanceof Post) {
            $classes[] = 'has-post';
        }

         return '<li id="li-' . $currentDate . '" class="' . implode(' ', $classes) .'">' . $day_number . '</li>';
    }
}