<?php
/**
 * Minimaler WebDAV-Server für Tests (Router für "php -S"). Speichert unter dem Ordner aus DAV_ROOT, URL-Präfix /dav,
 * Basic-Anmeldung nas / geheim. Kennt MKCOL, PUT, PROPFIND, HEAD, GET, DELETE. Gibt es die Datei ".truncate" im Wurzelordner,
 * speichert PUT nur die Hälfte (simuliert einen abgebrochenen Upload).
 */
$root = rtrim((string) getenv('DAV_ROOT'), '/\\');
$method = $_SERVER['REQUEST_METHOD'];
$path = rawurldecode((string) parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH));

if (($_SERVER['PHP_AUTH_USER'] ?? '') !== 'nas' || ($_SERVER['PHP_AUTH_PW'] ?? '') !== (getenv('DAV_PASS') ?: 'geheim')) {
    header('WWW-Authenticate: Basic realm="NAS"');
    http_response_code(401);
    exit;
}
if (!str_starts_with($path, '/dav')) { http_response_code(404); exit; }
$rel = trim(substr($path, 4), '/');
if (str_contains($rel, '..')) { http_response_code(400); exit; }
$file = $root . ($rel === '' ? '' : '/' . $rel);

$entry = function (string $href, string $name, ?string $full) {
    $isDir = $full === null || is_dir($full);
    $size = $isDir ? '' : '<D:getcontentlength>' . filesize($full) . '</D:getcontentlength>';
    $mod = $full !== null ? gmdate('D, d M Y H:i:s', filemtime($full)) . ' GMT' : '';
    return '<D:response><D:href>' . htmlspecialchars($href) . '</D:href><D:propstat><D:prop>' . $size
        . '<D:getlastmodified>' . $mod . '</D:getlastmodified><D:resourcetype>' . ($isDir ? '<D:collection/>' : '') . '</D:resourcetype></D:prop>'
        . '<D:status>HTTP/1.1 200 OK</D:status></D:propstat></D:response>';
};

switch ($method) {
    case 'MKCOL':
        if (file_exists($file)) { http_response_code(405); exit; }
        if (!is_dir(dirname($file))) { http_response_code(409); exit; }
        mkdir($file, 0755);
        http_response_code(201);
        break;
    case 'PUT':
        if (!is_dir(dirname($file))) { http_response_code(409); exit; }
        $data = (string) file_get_contents('php://input');
        if (file_exists($root . '/.truncate')) $data = substr($data, 0, (int) (strlen($data) / 2));
        $existed = file_exists($file);
        file_put_contents($file, $data);
        http_response_code($existed ? 204 : 201);
        break;
    case 'DELETE':
        if (!file_exists($file)) { http_response_code(404); exit; }
        is_dir($file) ? @rmdir($file) : unlink($file);
        http_response_code(204);
        break;
    case 'HEAD':
    case 'GET':
        if (!is_file($file)) { http_response_code(404); exit; }
        header('Content-Length: ' . filesize($file));
        if ($method === 'GET') readfile($file);
        break;
    case 'PROPFIND':
        if (!file_exists($file) && $rel !== '') { http_response_code(404); exit; }
        $xml = '<?xml version="1.0" encoding="utf-8"?><D:multistatus xmlns:D="DAV:">';
        $xml .= $entry($path, basename($rel), $rel === '' ? null : $file);
        if (is_dir($file) && ($_SERVER['HTTP_DEPTH'] ?? '1') !== '0') {
            foreach (scandir($file) ?: [] as $e) {
                if ($e === '.' || $e === '..' || $e[0] === '.') continue;
                $xml .= $entry(rtrim($path, '/') . '/' . rawurlencode($e), $e, $file . '/' . $e);
            }
        }
        $xml .= '</D:multistatus>';
        http_response_code(207);
        header('Content-Type: application/xml; charset=utf-8');
        echo $xml;
        break;
    default:
        http_response_code(405);
}