<?php
declare(strict_types=1);

if (($_SERVER["REQUEST_METHOD"] ?? "GET") !== "POST") { http_response_code(405); echo "Use POST"; exit; }
$file = $_FILES["note"] ?? null;
if (!is_array($file) || ($file["error"] ?? null) !== UPLOAD_ERR_OK || !is_string($file["tmp_name"] ?? null)) { http_response_code(422); echo "Upload failed"; exit; }
$temp = $file["tmp_name"];
if (!is_uploaded_file($temp) || filesize($temp) > 65536) { http_response_code(413); echo "Upload too large"; exit; }
$mime = (new finfo(FILEINFO_MIME_TYPE))->file($temp);
$content = file_get_contents($temp);
if ($mime !== "text/plain" || $content === false || !mb_check_encoding($content,"UTF-8") || str_contains($content,"\0")) { http_response_code(415); echo "Use plain UTF-8 text"; exit; }
$target = sys_get_temp_dir() . "/bhylu-upload-" . bin2hex(random_bytes(16)) . ".txt";
if (!move_uploaded_file($temp,$target)) { http_response_code(500); echo "Storage failed"; exit; }
try { echo "Stored ", filesize($target), " bytes privately"; } finally { unlink($target); }