<?php

namespace App\Middleware;

use App\Core\Request;
use App\Core\Response;

class SecurityHeaders implements MiddlewareInterface
{
    /**
     * Add security-hardening headers to the response.
     */
    public function handle(Request $request, Response $response, callable $next): void
    {
        // Enforce frame options to avoid clickjacking
        $response->header('X-Frame-Options', 'SAMEORIGIN');

        // Prevent MIME type sniffing
        $response->header('X-Content-Type-Options', 'nosniff');

        // Referrer policy
        $response->header('Referrer-Policy', 'no-referrer-when-downgrade');

        // Cross-Site Scripting protection
        $response->header('X-XSS-Protection', '1; mode=block');

        // HTTP Strict Transport Security (HSTS) - force HTTPS
        $response->header('Strict-Transport-Security', 'max-age=31536000; includeSubDomains; preload');

        // Content Security Policy (CSP)
        // Allow scripts from self, google fonts, CDN js, styles from self/fonts
        $csp = "default-src 'self'; " .
               "script-src 'self' 'unsafe-inline' 'unsafe-eval' https://cdn.jsdelivr.net; " .
               "style-src 'self' 'unsafe-inline' https://fonts.googleapis.com https://cdn.jsdelivr.net; " .
               "font-src 'self' https://fonts.gstatic.com; " .
               "img-src 'self' data: https:; " .
               "connect-src 'self'; " .
               "frame-ancestors 'none'; " .
               "base-uri 'self'; " .
               "form-action 'self';";
               
        $response->header('Content-Security-Policy', $csp);

        $next();
    }
}