calendar.php

<?php
/**
 * Created by PhpStorm.
 * Author: Misha Serenkov
 * Email: mi.serenkov@gmail.com
 * Date: 15.10.2017 20:51
 */

/**
 * @param int $month
 * @param int $year
 * @return array
 */
function get_calendar(int $month, int $year): array {
    $prevMonthCallback = 'calendar-month-';
    if ($month === 1) {
        $prevMonthCallback .= '12-'.($year-1);
    } else {
        $prevMonthCallback .= ($month-1).'-'.$year;
    }

    $nextMonthCallback = 'calendar-month-';
    if ($month === 12) {
        $nextMonthCallback .= '1-'.($year+1);
    } else {
        $nextMonthCallback .= ($month+1).'-'.$year;
    }

    $start = new \DateTime(sprintf('%d-%d-01', $year, $month));

    $calendarMap = [
        [
            ['text' => '<', 'callback_data' => $prevMonthCallback],
            ['text' => $start->format('F Y'), 'callback_data' => 'calendar-months_list-'.$year],
            ['text' => '>', 'callback_data' => $nextMonthCallback],
        ],
        [
            ['text' => 'Mon', 'callback_data' => 'null_callback'],
            ['text' => 'Tue', 'callback_data' => 'null_callback'],
            ['text' => 'Wed', 'callback_data' => 'null_callback'],
            ['text' => 'Thu', 'callback_data' => 'null_callback'],
            ['text' => 'Fri', 'callback_data' => 'null_callback'],
            ['text' => 'Sat', 'callback_data' => 'null_callback'],
            ['text' => 'Sun', 'callback_data' => 'null_callback'],
        ],
    ];


    $end = clone $start;
    $end->modify('last day of this month');
    $iterEnd = clone $start;
    $iterEnd->modify('first day of next month');
    $row = 2;
    foreach (new DatePeriod($start, new DateInterval("P1D"), $iterEnd) as $date) {
        /** @var \DateTime $date */

        if (!isset($calendarMap[$row])) {
            $calendarMap[$row] = array_combine([1, 2, 3, 4, 5, 6, 7], [[], [], [], [], [], [], []]);
        }

        $dayIterator = (int)$date->format('N');
        if ($dayIterator != 1 && $start->format('d') === $date->format('d')) {
            for ($i = 1; $i < $dayIterator; $i++){
                $calendarMap[$row][$i] = ['text' => ' ', 'callback_data' => 'null_callback'];
            }
        }

        $calendarMap[$row][$dayIterator] = ['text' => $date->format('d'), 'callback_data' => sprintf('calendar-day-%d-%d-%d', $date->format('d'), $month, $year)];

        if ($dayIterator < 7 && $end->format('d') === $date->format('d')) {
            for ($i = $dayIterator+1; $i <= 7; $i++){
                $calendarMap[$row][$i] = ['text' => ' ', 'callback_data' => 'null_callback'];
            }
            $calendarMap[$row] = array_values($calendarMap[$row]);
            break;
        }

        if ($dayIterator === 7) {
            $calendarMap[$row] = array_values($calendarMap[$row]);
            $row++;
        }
    }

    return $calendarMap;
}

function get_months_list(int $year): array {
    $listMap = [
        [
            ['text' => '<', 'callback_data' => 'calendar-year-'.($year-1)],
            ['text' => $year, 'callback_data' => 'calendar-years_list-'.$year],
            ['text' => '>', 'callback_data' => 'calendar-year-'.($year+1)],
        ],
    ];

    $row = 1;

    for($month = 1; $month <= 12; $month++) {
        $listMap[$row][] = ['text' => date('F', strtotime(sprintf('%d-%d-01', $year, $month))), 'callback_data' => sprintf('calendar-month-%d-%d', $month, $year)];

        if ($month === 3 || $month === 6 || $month === 9) {
            $row++;
        }
    }

    return $listMap;
}

function get_years_list(int $centerYear): array {
    $prevYear = $centerYear-25;
    $nextYear = $centerYear+25;
    $listMap = [
        [
            $prevYear <= 76 ? ['text' => ' ', 'callback_data' => 'null_callback'] : ['text' => '<', 'callback_data' => 'calendar-years_list-'.$prevYear],
//            ['text' => ' ', 'callback_data' => 'null_callback'],
            $nextYear >= 10024 ? ['text' => ' ', 'callback_data' => 'null_callback'] : ['text' => '>', 'callback_data' => 'calendar-years_list-'.$nextYear],
        ],
    ];

    $row = 1;
    $i = 0;

    for ($year = ($centerYear - 12); $year <= ($centerYear+12); $year++) {
        if ($year >= 100 && $year <= 9999) {
            $listMap[$row][] = ['text' => $year, 'callback_data' => sprintf('calendar-months_list-%d', $year)];
            $i++;
        } else {
//            $listMap[$row][] = ['text' => ' ', 'callback_data' => sprintf('calendar-months_list-%d', $year)];
        }

        if ($i === 5 || $i === 10 || $i === 15 || $i === 20) {
            $row++;
        }
    }


    return $listMap;
}