<?php

namespace App\Services;

use App\Models\Todo;
use Sabre\DAV\Client;
use Sabre\DAV\Xml\Service;
use Illuminate\Support\Facades\Log;
use Sabre\VObject;


class CalendarInfo
{
    public $id;
    public $displayName;
    public $url;
    public $ctag;
    public $syncToken;
    public $color;
}


class CaldavService
{
    protected Client $client;
    protected string $baseUrl;
    protected string $userName;
    protected CalendarInfo $calendar;

    public function __construct()
    {
        $cfg = config('caldav', []);

        $this->calendar = new CalendarInfo();
        $this->baseUrl = rtrim($cfg['base_url'] ?? '', '/') . '/';
        $this->userName = $cfg['username'] ?? '';
        $this->calendar->displayName = $cfg['calendar_name'] ?? '';

        if (
            empty($this->baseUrl) ||
            empty($this->userName) ||
            empty($cfg['password'] ?? '') ||
            empty($this->calendar->displayName)
        ) {
            Log::warning('CalDAV config incomplete', ['base' => $this->baseUrl, 'calendarName' => $this->calendar->displayName, 'userName' => $this->userName]);
        }

        $this->client = new Client([
            'baseUri'   => $this->baseUrl,
            'userName'  => $cfg['username'] ?? null,
            'password'  => $cfg['password'] ?? null,
            'authType' => \Sabre\DAV\Client::AUTH_BASIC,
            'userAgent' => $cfg['user_agent'] ?? 'caldav-client',
        ]);

        $this->getCalendarInfo();
    }

    /**
     * Requests all calendars of the user and gets the ID that belongs to the calendar name
     */
    public function getCalendarId()
    {
        $response = $this->client->propFind(
            'calendars/' . $this->userName . '/',
            [
                '{DAV:}resourcetype',
                '{DAV:}displayname',
            ],
            1
        );

        foreach ($response as $href => $node) {
            if (array_key_exists('{DAV:}displayname', $node) && strcasecmp($node['{DAV:}displayname'], $this->calendar->displayName) == 0) {
                $this->calendar->url = $href;

                $parts = explode('/', trim($href, '/'));
                return array_pop($parts);
            }
        }
    }

    /**
     * Request information about the calendar (ctag, sync-token, color)
     */
    public function getCalendarInfo()
    {
        $this->calendar->id = $this->getCalendarId();

        $response = $this->client->propFind(
            'calendars/' . $this->userName . '/' . $this->calendar->id,
            [
                '{DAV:}displayname',
                '{http://calendarserver.org/ns/}getctag',
                '{DAV:}sync-token',
                '{http://apple.com/ns/ical/}calendar-color',
            ]
        );

        // TODO: store ctag to compare whether the calendar has changed
        $this->calendar->ctag = $response['{http://calendarserver.org/ns/}getctag'];
        $this->calendar->syncToken = $response['{DAV:}sync-token'];
        $this->calendar->color = $response['{http://apple.com/ns/ical/}calendar-color'];

        return $this->calendar;
    }

    public function getTodos()
    {
        $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 name="VTODO" />'
            . '        </c:comp-filter>'
            . '    </c:filter>'
            . '</c:calendar-query>';

        $headers = [
            'Depth' => '1',
            'Content-Type' => 'application/xml; charset=utf-8',
            'Prefer' => 'return-minimal'
        ];

        $response = $this->client->request(
            'REPORT',
            'calendars/' . $this->userName . '/' . $this->calendar->id,
            $body,
            $headers
        );


        // Sabre\DAV\Xml\Service
        $service = new Service();
        // Sabre\DAV\Xml\Response\MultiStatus
        $multiStatus = $service->parse($response['body']);
        // Sabre\DAV\Xml\Element\Response
        $responses = $multiStatus->getResponses();

        $todos = [];
        foreach ($responses as $key => $response) {
            $href = $response->getHref();
            $properties = $response->getResponseProperties();
            $calendarData = $properties[200]['{urn:ietf:params:xml:ns:caldav}calendar-data'];
            $etag = $properties[200]['{DAV:}getetag'];
            $vcalendar = VObject\Reader::read($calendarData);

            // Create new todo
            $todo = new Todo();

            // Map VTODO -> App\Model\Todo
            $todo->id = isset($vcalendar->VTODO->UID) ? $vcalendar->VTODO->UID->getValue() : uniqid();
            $todo->etag = $etag;
            $todo->title = isset($vcalendar->VTODO->SUMMARY) ? $vcalendar->VTODO->SUMMARY->getValue() : 'Neues Todo';
            if (isset($vcalendar->VTODO->DESCRIPTION)) $todo->description = $vcalendar->VTODO->DESCRIPTION->getValue();
            $todo->type_id = 2;
            $todo->url = $href;
            if (isset($vcalendar->VTODO->DUE)) $todo->due_date = $vcalendar->VTODO->DUE->getDateTime();
            if(isset($vcalendar->VTODO->RRULE)) $todo->recurring = $vcalendar->VTODO->RRULE->getValue();
            if(isset($vcalendar->VTODO->PRIORITY)) $todo->priority = $vcalendar->VTODO->PRIORITY->getValue();
            if(isset($vcalendar->VTODO->STATUS)) $todo->status = $vcalendar->VTODO->STATUS->getValue();
            if(isset($vcalendar->VTODO->{'RELATED-TO'})) $todo->parent = $vcalendar->VTODO->{'RELATED-TO'}->getValue();
            $todo->created_at = $vcalendar->VTODO->CREATED->getDateTime();
            $todo->last_modified = $vcalendar->VTODO->{'LAST-MODIFIED'}->getDateTime();

            $todos[] = $todo;
        }

        return $todos;
    }
}