<?php

namespace App\Webdav;

use Sabre\DAV\Client;

/**
 * class CaldavClient.
 *
 * @author Simon Vieille <simon@deblan.fr>
 */
class CaldavClient
{
    protected string $host;
    protected string $username;
    protected string $password;
    protected ?Client $client = null;

    public function __construct(string $host, string $username, string $password)
    {
        $this->host = $host;
        $this->username = $username;
        $this->password = $password;
    }

    protected function getClient(): Client
    {
        if (null === $this->client) {
            $this->client = new Client([
                'baseUri' => $this->host,
                'userName' => $this->username,
                'password' => $this->password,
            ]);
        }

        return $this->client;
    }

    public function getEvents(string $calendarUri)
    {
        $body = '<c:calendar-query xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:caldav">
            <d:prop>
                <d:getetag />
                <c:calendar-data />
            </d:prop>
            <c:filter>
                <c:comp-filter name="VCALENDAR">
                </c:comp-filter>
            </c:filter>
        </c:calendar-query>';

        $response = $this->getClient()->request(
            'REPORT',
            $calendarUri,
            $body,
            [
                'Depth' => 1,
                'Prefer' => 'return-minimal',
                'Content-Type' => 'application/xml; charset=utf-8',
            ]
        );

        $body = $response['body'];
        $events = [];
        preg_match_all('#<cal:calendar-data>(.+)</cal:calendar-data>#isU', $body, $rawEvents, PREG_SET_ORDER);

        foreach ($rawEvents as $rawEvent) {
            $events[] = $this->createEvent($rawEvent[1]);
        }

        return $events;
    }

    protected function createEvent(string $rawEvent): Event
    {
        preg_match_all('/
            ^([A-Z\-]+)[:;]{1}([^\n]+)\n
            ((\ [^\n]+\n)*\3*)
        /xm', $rawEvent, $matches, PREG_SET_ORDER);

        $datas = [];

        foreach ($matches as $match) {
            $key = $match[1];

            if (isset($datas[$key])) {
                continue;
            }

            $lines = array_map(fn ($line) => trim($line), explode("\n", $match[2].$match[3]));
            $lines = str_replace('\\n', "\n", implode('', $lines));

            if (in_array($key, ['DTSTART', 'DTEND'])) {
                if (empty($lines)) {
                    continue;
                }

                @list($tz, $time) = explode(':', $lines);

                if (empty($time)) {
                    continue;
                }

                $lines = new \DateTime($time);
            }

            $datas[$key] = $lines;
        }

        $event = new Event();
        $event
            ->setUid($datas['UID'])
            ->setSummary($datas['SUMMARY'] ?? null)
            ->setDescription($datas['DESCRIPTION'] ?? null)
            ->setLocation($datas['LOCATION'] ?? null)
            ->setSummary($datas['SUMMARY'] ?? null)
            ->setStartAt($datas['DTSTART'] ?? null)
            ->setFinishAt($datas['DTEND'] ?? null)
        ;

        return $event;
    }
}