<?php
// read vor.txt and generate vor.md, inserting dates if missing
date_default_timezone_set("CET");
setlocale(LC_TIME, 'de_DE.utf8');
$file_txt = 'vor.txt';
$file_md = 'vor.md';
$fil = file($file_txt, FILE_IGNORE_NEW_LINES);
// Insert header
$arr = ['| | |  |', '|:------|:------|:------|'];
$ts=(new DateTime('first day of this month'))->getTimeStamp();
$tues_ts = strtotime('fourth tuesday of this month', $ts);

// Are we past the fourth Tuesday of     the month? 
if ((new DateTime())->getTimeStamp() >= $tues_ts) {
    $ts = strtotime('+1 month', $ts);
}    

// This for PHP >= 8.1 as the old strftime will be deprecated by then
// $date_time = new DateTime();
// $date_time->setTimestamp(strtotime('fourth tuesday of this month', $ts));
foreach ($fil as $line) {
    // Skip empty lines
    if (strlen($line)) {
        $fields = array_filter(explode('|', $line));
        if (count($fields) == 2) {
            // Date missing, insert
            $tuesday = strftime('%A, %d.%m.%Y ', strtotime('fourth tuesday of this month', $ts));
            // $tuesday = datefmt_format_object($date_time, 'cccc, d.M.yyyy ', 'de_DE.utf8');
            array_unshift($fields, $tuesday);
        }
        $ts = strtotime('+1 month', $ts);
        $li = implode('|', $fields);
        // Insert leading and trailing spaces if required
        if ($li[0] != ' ') {
            $li = ' ' . $li;
        }
        if (substr($li, -1) != ' ') {
            $li = $li . ' ';
        }
        array_push($arr, '|' . $li . '|');    
    }
}
file_put_contents($file_md, implode(PHP_EOL, $arr) . PHP_EOL);
?>