<?php

declare(strict_types=1);

namespace Steuerkram;

use Steuerkram\Auth;

class Router
{
    private array $routes = [];

    public function add(string $method, string $pattern, callable $handler): void
    {
        $this->routes[] = [
            'method'  => strtoupper($method),
            'pattern' => $pattern,
            'handler' => $handler,
        ];
    }

    public function get(string $pattern, callable $handler): void
    {
        $this->add('GET', $pattern, $handler);
    }

    public function post(string $pattern, callable $handler): void
    {
        $this->add('POST', $pattern, $handler);
    }

    public function put(string $pattern, callable $handler): void
    {
        $this->add('PUT', $pattern, $handler);
    }

    public function delete(string $pattern, callable $handler): void
    {
        $this->add('DELETE', $pattern, $handler);
    }

    public function dispatch(): void
    {
        $method = strtoupper($_SERVER['REQUEST_METHOD'] ?? 'GET');
        // Support method override via hidden _method field or X-HTTP-Method-Override header
        if ($method === 'POST') {
            $override = $_POST['_method'] ?? $_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE'] ?? null;
            if ($override) {
                $method = strtoupper($override);
            }
        }

        $uri = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH);
        $uri = '/' . trim($uri, '/');
        if ($uri === '') $uri = '/';

        if (in_array($method, ['POST', 'PUT', 'DELETE', 'PATCH'], true)) {
            $token = $_POST['csrf_token'] ?? $_SERVER['HTTP_X_CSRF_TOKEN'] ?? '';
            Auth::validateCsrfToken($token);
        }

        foreach ($this->routes as $route) {
            if ($route['method'] !== $method) continue;

            $params = $this->match($route['pattern'], $uri);
            if ($params !== null) {
                ($route['handler'])($params);
                return;
            }
        }

        http_response_code(404);
        $view = new View();
        $view->render('layout/404.php', ['uri' => $uri]);
    }

    private function match(string $pattern, string $uri): ?array
    {
        // Convert route pattern to regex: {id} → named capture
        $regex = preg_replace('/\{(\w+)\}/', '(?P<$1>[^/]+)', $pattern);
        $regex = '#^' . $regex . '$#';

        if (preg_match($regex, $uri, $matches)) {
            return array_filter($matches, 'is_string', ARRAY_FILTER_USE_KEY);
        }

        return null;
    }
}