Adds helper to manage all static assets of a theme

app/helpers/theme-asset.php

@@ -0,0 +1,79 @@
+<?php
+/**
+ * Theme Asset Handler
+ *
+ * Serves theme assets (images, CSS, JS, etc.) securely by checking if the requested
+ * theme and asset path are valid and accessible.
+ */
+
+// Include necessary files
+require_once __DIR__ . '/../config/init.php';
+require_once __DIR__ . '/../core/ConfigLoader.php';
+
+// Basic security checks
+if (!isset($_GET['theme']) || !preg_match('/^[a-zA-Z0-9_-]+$/', $_GET['theme'])) {
+    http_response_code(400);
+    exit('Invalid theme specified');
+}
+
+if (!isset($_GET['path']) || empty($_GET['path'])) {
+    http_response_code(400);
+    exit('No asset path specified');
+}
+
+$themeId = $_GET['theme'];
+$assetPath = $_GET['path'];
+
+// Validate asset path (only alphanumeric, hyphen, underscore, dot, and forward slash)
+if (!preg_match('/^[a-zA-Z0-9_\-\.\/]+$/', $assetPath)) {
+    http_response_code(400);
+    exit('Invalid asset path');
+}
+
+// Prevent directory traversal
+if (strpos($assetPath, '..') !== false) {
+    http_response_code(400);
+    exit('Invalid asset path');
+}
+
+// Build full path to the asset
+$fullPath = __DIR__ . "/../../themes/$themeId/$assetPath";
+
+// Check if the file exists and is readable
+if (!file_exists($fullPath) || !is_readable($fullPath)) {
+    http_response_code(404);
+    exit('Asset not found');
+}
+
+// Determine content type based on file extension
+$extension = strtolower(pathinfo($assetPath, PATHINFO_EXTENSION));
+$contentTypes = [
+    'css'  => 'text/css',
+    'js'   => 'application/javascript',
+    'json' => 'application/json',
+    'png'  => 'image/png',
+    'jpg'  => 'image/jpeg',
+    'jpeg' => 'image/jpeg',
+    'gif'  => 'image/gif',
+    'svg'  => 'image/svg+xml',
+    'webp' => 'image/webp',
+    'woff' => 'font/woff',
+    'woff2' => 'font/woff2',
+    'ttf'  => 'font/ttf',
+    'eot'  => 'application/vnd.ms-fontobject',
+];
+
+$contentType = $contentTypes[$extension] ?? 'application/octet-stream';
+
+// Set proper headers
+header('Content-Type: ' . $contentType);
+header('Content-Length: ' . filesize($fullPath));
+
+// Cache for 24 hours (86400 seconds)
+$expires = 86400;
+header('Cache-Control: public, max-age=' . $expires);
+header('Expires: ' . gmdate('D, d M Y H:i:s', time() + $expires) . ' GMT');
+header('Pragma: cache');
+
+// Output the file
+readfile($fullPath);