<?php

function now(): string { return date('Y-m-d H:i:s'); }

function e(string $s): string { return htmlspecialchars($s, ENT_QUOTES, 'UTF-8'); }

function redirect(string $to): void {
  header("Location: $to");
  exit;
}

function require_int($v, $name='id'): int {
  if (!is_numeric($v) || (int)$v <= 0) throw new RuntimeException("Invalid $name");
  return (int)$v;
}

function safe_slug(string $s): string {
  $s = strtolower(trim($s));
  $s = preg_replace('/[^a-z0-9._-]+/', '-', $s);
  $s = trim($s, '-');
  if ($s === '') throw new RuntimeException("Invalid name");
  return $s;
}

function safe_branch(string $b): string {
  $b = trim($b);
  if ($b === '') throw new RuntimeException("Invalid branch");
  if (!preg_match('/^[a-zA-Z0-9._\/-]+$/', $b)) throw new RuntimeException("Invalid branch");
  if (str_contains($b, '..')) throw new RuntimeException("Invalid branch");
  return $b;
}

function safe_path(string $p): string {
  $p = str_replace('\\', '/', (string)$p);
  $p = ltrim($p, '/');
  if ($p === '') return '';
  if (str_contains($p, "\0") || str_contains($p, '..')) throw new RuntimeException("Invalid path");
  if (!preg_match('/^[a-zA-Z0-9._\/-]+$/', $p)) throw new RuntimeException("Invalid path");
  return $p;
}

function flash_set(string $key, string $msg): void {
  start_session();
  $_SESSION['_flash'][$key] = $msg;
}

function flash_get(string $key): ?string {
  start_session();
  if (!isset($_SESSION['_flash'][$key])) return null;
  $m = $_SESSION['_flash'][$key];
  unset($_SESSION['_flash'][$key]);
  return $m;
}