<?php

# requirements
require_once 'include/config.php';
require_once 'include/ICal/ICal.php';
require_once 'include/ICal/Event.php';

# Fix relative path
$cachefile = 'cache/'.$cachefile;

# Init Calendar
$ical = new \ICal\ICal();

# Caching and load calendar
if (!file_exists($cachefile) || (filemtime($cachefile) + $cachetime < time())) {
    $context = stream_context_create(['http' => ['timeout' => 10]]);
    $ical_str = @file_get_contents($ical_url, false, $context);
    
    if ($ical_str !== false && strpos($ical_str, 'BEGIN:VCALENDAR') !== false) {
        file_put_contents($cachefile, $ical_str);
        $ical->initString($ical_str);
    } else {
        if (file_exists($cachefile)) $ical->initFile($cachefile);
    }
} else {
    $ical->initFile($cachefile);
}

# Load calendar entries
$period_val = filter_input(INPUT_GET, 'period', FILTER_VALIDATE_INT, ['options' => ['min_range' => 1, 'max_range' => 12]]) ?: 1;
$filter = filter_input(INPUT_GET, 'filter', FILTER_SANITIZE_SPECIAL_CHARS); // FILTER_UNSAFE_RAW

$events = $ical->sortEventsWithOrder($ical->eventsFromInterval($period_val . ' month'));
$result = [];

foreach ($events as $event) {
    $cat = $event->categories ?? '';

    if ($filter && stripos($cat, $filter) === false) continue;
    if (stripos($cat, "hidden") !== false) continue;

    $start = new DateTime($event->dtstart);
    $end = new DateTime($event->dtend);
    $uid = $event->uid;

    $interval = new DateInterval('P1D');
    $period = new DatePeriod($start, $interval, $end);

    foreach ($period as $dt) {
        $date = $dt->format("Y-m-d");
        $result[$date][$uid] = [
            "dtstart"     => $start->format(DateTime::ATOM), //$ical->iCalDateToDateTime($event->dtstart_array[3])->format(DateTime::ATOM);
            "dtend"       => $end->format(DateTime::ATOM), //$ical->iCalDateToDateTime($event->dtend_array[3])->format(DateTime::ATOM);
            "datestr"     => (isset($event->dtstart_array[0]["VALUE"]) && $event->dtstart_array[0]["VALUE"] == 'DATE') ? '' : $start->format('H:i'),
            "summary"     => mb_strimwidth($event->summary, 0, 255, "..."),
            "location"    => mb_strimwidth($event->location ?? '', 0, 255, "..."),
            "description" => mb_strimwidth($event->description ?? '', 0, 255, "...")
        ];
        if(!empty($cat)) $result[$date][$uid]["categories"] = $cat;
    }
}

# Allow every page to load this json
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=utf-8");
echo json_encode($result, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);