conferences

<?php
date_default_timezone_set("Europe/Sofia");
$page = $_GET['page'];
$pageSize = $_GET['pageSize'];
$text = $_GET['conferences'];

$pattern = "/\\[(\\d\\d\\d\\d-\\d\\d-\\d\\d|\\d\\d\\d\\d\\/\\d\\d\\/\\d\\d)\\s*,\\s*(#[a-zA-Z.-]+)\\s*,\\s*'(.+?)'\\s*,\\s*([a-zA-Z,-]+)\\s*,\\s*(\\d+)\\s*,\\s*(\\d+)\\]/";
$events = array();
$dateArr = array();
$locationArr = array();
$ticketsArr = array();
$nameArr = array();

preg_match_all($pattern, $text, $matches);


for ($i = 0; $i < count($matches[0]); $i++) {
    $date = trim($matches[1][$i]);
    $hash = trim($matches[2][$i]);
    $name = trim($matches[3][$i]);
    $location = trim($matches[4][$i]);
    $allTickets = trim($matches[5][$i]);
    $ticketsSold = trim($matches[6][$i]);

    $events[] = [
        "date" => date_create($date),
        "hash" => $hash,
        "name" => $name,
        "location" => $location,
        "all-tickets" => $allTickets,
        "tickets-sold" => $ticketsSold
    ];

    $nameArr[] = $name;
    $dateArr[] = date_create($date);
    $locationArr[] = $location;
    $ticketsArr[] = $allTickets;
}



array_multisort($dateArr, SORT_DESC, $locationArr, SORT_ASC, $ticketsArr, SORT_DESC, $nameArr, SORT_ASC, $events);

var_dump($events);
$currPage = ($page - 1) * $pageSize;
$endPage = $currPage + $pageSize;
$len = count($events);


for ($i = 0; $i < $len; $i++) {
    if ($i <  $currPage || $i >= $endPage) {
        unset($events[$i]);
    }
}


$eventsGrouped = array();



foreach ($events as $event) {
    $key = $event['date']->format("Y-m-d");
    if (!isset($eventsGrouped[$key])) {
        $eventsGrouped[$key] = array();
    }
    $today = date_create("2015-05-03");
    $diff = $event['date']->diff($today);
    $days = $diff->days;
    if ($event['date'] < $today) {
        $days = "-" . $days;
    } else if ($event['date'] >= $today) {
        $days = "+" . $days;
    }

    $seatsLeft = intval($event['all-tickets']) - intval($event['tickets-sold']);
    $eventsGrouped[$key][] = [
        "name" => $event['name'],
        "hash" => $event['hash'],
        "days-left" => $days,
        "seats-left" => $seatsLeft
    ];
}


echo "<table border=\"1\" cellpadding=\"5\">";
echo "<tr>";
echo "<th>Date</th>";
echo "<th>Event name</th>";
echo "<th>Event hash</th>";
echo "<th>Days left</th>";
echo "<th>Seats left</th>";
echo "</tr>";
if (empty($eventsGrouped)) {
    echo "<tr><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr>";
} else {
    foreach ($eventsGrouped as $key => $value) {
        $rowspan = count($value);
        if ($rowspan > 1) {
            for ($i = 0; $i < count($value); $i++) {
                if ($i == 0) {
                    echo "<tr><td rowspan=\"$rowspan\">$key</td>";
                } else {
                    echo "<tr>";
                }
                $currName = htmlspecialchars($value[$i]['name']);
                $currName = str_replace("'", "", $currName);
                echo "<td>" . $currName . "</td>";
                echo "<td>" . htmlspecialchars($value[$i]['hash']) . "</td>";
                echo "<td>" . htmlspecialchars($value[$i]['days-left']) . " days</td>";
                echo "<td>" . htmlspecialchars($value[$i]['seats-left']) . " seats left</td>";
                echo "</tr>";
            }
        } else {
            $currName = htmlspecialchars($value[0]['name']);
            $currName = str_replace("'", "", $currName);
            echo "<tr><td>$key</td>";
            echo "<td>" . $currName . "</td>";
            echo "<td>" . htmlspecialchars($value[0]['hash']) . "</td>";
            echo "<td>" . htmlspecialchars($value[0]['days-left']) . " days</td>";
            echo "<td>" . htmlspecialchars($value[0]['seats-left']) . " seats left</td>";
            echo "</tr>";
        }
    }
}
echo "</table>";