<?php
/* Copyright (C) 2026		Eduard Wisch				<data@data-it-solution.de>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

/**
 * \file    agendwrapper/proxy.php
 * \ingroup agendwrapper
 * \brief   ICS-Proxy-Endpunkt - liefert bereinigtes ICS an Dolibarr
 *
 * Wird als externe Kalender-URL in Dolibarr eingetragen.
 * Authentifizierung ueber API-Key im GET-Parameter.
 */

if (!defined('NOTOKENRENEWAL')) {
	define('NOTOKENRENEWAL', '1');
}
if (!defined('NOREQUIREMENU')) {
	define('NOREQUIREMENU', '1');
}
if (!defined('NOREQUIREHTML')) {
	define('NOREQUIREHTML', '1');
}
if (!defined('NOREQUIREAJAX')) {
	define('NOREQUIREAJAX', '1');
}
if (!defined('NOLOGIN')) {
	define('NOLOGIN', '1');
}
if (!defined('NOCSRFCHECK')) {
	define('NOCSRFCHECK', '1');
}

// Dolibarr-Umgebung laden
$res = 0;
if (!$res && !empty($_SERVER["CONTEXT_DOCUMENT_ROOT"])) {
	$res = @include $_SERVER["CONTEXT_DOCUMENT_ROOT"]."/main.inc.php";
}
$tmp = empty($_SERVER['SCRIPT_FILENAME']) ? '' : $_SERVER['SCRIPT_FILENAME'];
$tmp2 = realpath(__FILE__);
$i = strlen($tmp) - 1;
$j = strlen($tmp2) - 1;
while ($i > 0 && $j > 0 && isset($tmp[$i]) && isset($tmp2[$j]) && $tmp[$i] == $tmp2[$j]) {
	$i--;
	$j--;
}
if (!$res && $i > 0 && file_exists(substr($tmp, 0, ($i + 1))."/main.inc.php")) {
	$res = @include substr($tmp, 0, ($i + 1))."/main.inc.php";
}
if (!$res && $i > 0 && file_exists(dirname(substr($tmp, 0, ($i + 1)))."/main.inc.php")) {
	$res = @include dirname(substr($tmp, 0, ($i + 1)))."/main.inc.php";
}
if (!$res && file_exists("../main.inc.php")) {
	$res = @include "../main.inc.php";
}
if (!$res && file_exists("../../main.inc.php")) {
	$res = @include "../../main.inc.php";
}
if (!$res) {
	http_response_code(500);
	die('Include of main fails');
}

require_once DOL_DOCUMENT_ROOT.'/core/lib/security.lib.php';
dol_include_once('/agendwrapper/class/IcsProxy.class.php');

// Parameter
$calNumber = GETPOSTINT('cal');
$apiKey = GETPOST('key', 'alpha');

// Kalender-Nummer validieren
if (!in_array($calNumber, array(1, 2))) {
	http_response_code(400);
	die('Ungueltiger Kalender-Parameter');
}

// Modul aktiv?
if (!isModEnabled('agendwrapper')) {
	http_response_code(503);
	die('Modul nicht aktiviert');
}

// API-Key pruefen
$storedKey = getDolGlobalString('AGENDWRAPPER_API_KEY');
if (empty($storedKey) || empty($apiKey) || $apiKey !== $storedKey) {
	http_response_code(403);
	die('Zugriff verweigert');
}

// ICS generieren
$proxy = new IcsProxy($db);
$ics = $proxy->getCleanIcs($calNumber);

if ($ics === false) {
	http_response_code(502);
	dol_syslog('AgendWrapper proxy.php Fehler: '.$proxy->error, LOG_ERR);
	die('Fehler: '.$proxy->error);
}

// ICS ausliefern
header('Content-Type: text/calendar; charset=utf-8');
header('Content-Disposition: inline; filename="calendar'.$calNumber.'.ics"');
header('Cache-Control: no-cache, must-revalidate');
header('X-AgendWrapper: 1.0');
echo $ics;