<?php

function auth_get_client_ip(): string
{
    $forwarded = $_SERVER["HTTP_X_FORWARDED_FOR"] ?? "";
    if ($forwarded) {
        $parts = explode(",", $forwarded);
        return trim($parts[0]);
    }
    return $_SERVER["REMOTE_ADDR"] ?? "unknown";
}

function auth_read_json(): array
{
    $raw = file_get_contents("php://input");
    if (!$raw) {
        return [];
    }
    $decoded = json_decode($raw, true);
    return is_array($decoded) ? $decoded : [];
}

function auth_json_response(int $status, array $payload): void
{
    http_response_code($status);
    header("Content-Type: application/json; charset=utf-8");
    echo json_encode($payload, JSON_UNESCAPED_UNICODE);
    exit;
}

function auth_get_site_key(array $data): string
{
    $siteKey = $data["siteKey"] ?? $_GET["siteKey"] ?? "";
    return is_string($siteKey) ? trim($siteKey) : "";
}

function auth_is_valid_login(string $login): bool
{
    $len = mb_strlen($login, "UTF-8");
    return $len >= 3 && $len <= 64;
}

function auth_is_valid_password(string $password): bool
{
    $len = mb_strlen($password, "UTF-8");
    return $len >= 8 && $len <= 128;
}

function auth_is_valid_site_key(string $siteKey): bool
{
    $len = mb_strlen($siteKey, "UTF-8");
    return $len >= 3 && $len <= 255;
}