<?php
declare(strict_types=1);

ini_set('session.cookie_httponly', '1');
ini_set('session.use_strict_mode', '1');

session_start();

$config = require '/var/www/TRAILER_TREKKER/private/config.php';

function json_response($data, int $code = 200): never {
  http_response_code($code);
  header('Content-Type: application/json; charset=utf-8');
  header('Cache-Control: no-store');
  echo json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
  exit;
}

function require_login(): void {
  if (empty($_SESSION['tt_logged_in'])) {
    json_response(['ok' => false, 'error' => 'not_authenticated'], 401);
  }
}

function read_json_file(string $path): array {
  if (!file_exists($path)) return [];
  $raw = file_get_contents($path);
  if ($raw === false || trim($raw) === '') return [];
  $data = json_decode($raw, true);
  return is_array($data) ? $data : [];
}

function write_json_file_atomic(string $path, string $json): bool {
  // Ensure directory exists
  $dir = dirname($path);
  if (!is_dir($dir)) {
    if (!mkdir($dir, 0750, true)) return false;
  }

  $fp = fopen($path, 'c+');
  if ($fp === false) return false;

  $ok = false;
  if (flock($fp, LOCK_EX)) {
    ftruncate($fp, 0);
    rewind($fp);
    $bytes = fwrite($fp, $json);
    fflush($fp);
    flock($fp, LOCK_UN);
    $ok = ($bytes !== false);
  }
  fclose($fp);
  return $ok;
}