refactor(app): Improve error handling and HTML response processing in root route

- Enhanced error logging to include specific context for index.html processing errors.
- Added checks to ensure headers are sent only when appropriate, preventing potential issues with multiple responses.
- Improved comments for clarity on the purpose of code sections, particularly around HTML processing and error handling.

feat(config): Log raw FOOTER_LINKS from environment variables

- Introduced logging for the raw FOOTER_LINKS value to aid in debugging and configuration verification.
- Maintained existing functionality while enhancing visibility into configuration values.

src/app.js

@@ -46,28 +46,19 @@ app.use('/api/files', requirePin(config.pin), downloadLimiter, fileRoutes);
 
 // Root route
 app.get('/', (req, res) => {
-  // Check if the PIN is configured and the cookie exists
-  if (config.pin && (!req.cookies?.DUMBDROP_PIN || !safeCompare(req.cookies.DUMBDROP_PIN, config.pin))) {
-    return res.redirect('/login.html');
-  }
-  
-  let html = fs.readFileSync(path.join(__dirname, '../public', 'index.html'), 'utf8');
-  html = html.replace(/{{SITE_TITLE}}/g, config.siteTitle);
-  html = html.replace('{{AUTO_UPLOAD}}', config.autoUpload.toString());
-  html = html.replace('{{MAX_RETRIES}}', config.clientMaxRetries.toString());
-  // Ensure baseUrl has a trailing slash for correct asset linking
-  const baseUrlWithSlash = config.baseUrl.endsWith('/') ? config.baseUrl : config.baseUrl + '/';
-  html = html.replace(/{{BASE_URL}}/g, baseUrlWithSlash);
-  html = injectDemoBanner(html);
-  res.send(html);
   try {
+    // Check if the PIN is configured and the cookie exists
+    if (config.pin && (!req.cookies?.DUMBDROP_PIN || !safeCompare(req.cookies.DUMBDROP_PIN, config.pin))) {
+      return res.redirect('/login.html');
+    }
+    
     let html = fs.readFileSync(path.join(__dirname, '../public', 'index.html'), 'utf8');
     
     // Standard replacements
     html = html.replace(/{{SITE_TITLE}}/g, config.siteTitle);
     html = html.replace('{{AUTO_UPLOAD}}', config.autoUpload.toString());
     html = html.replace('{{MAX_RETRIES}}', config.clientMaxRetries.toString());
-    // Ensure baseUrl has a trailing slash
+    // Ensure baseUrl has a trailing slash for correct asset linking
     const baseUrlWithSlash = config.baseUrl.endsWith('/') ? config.baseUrl : config.baseUrl + '/';
     html = html.replace(/{{BASE_URL}}/g, baseUrlWithSlash);
     
@@ -84,11 +75,18 @@ app.get('/', (req, res) => {
     }
     html = html.replace('{{FOOTER_CONTENT}}', footerHtml);
 
+    // Inject demo banner if applicable
     html = injectDemoBanner(html);
+
+    // Send the final processed HTML
     res.send(html);
+
   } catch (err) {
-    logger.error(`Error processing index.html: ${err.message}`);
+    logger.error(`Error processing index.html for / route: ${err.message}`);
-    res.status(500).send('Error loading page');
+    // Check if headers have already been sent before trying to send an error response
+    if (!res.headersSent) {
+      res.status(500).send('Error loading page');
+    }
   }
 });
 
@@ -138,6 +136,10 @@ app.use(express.static('public'));
 // Error handling middleware
 app.use((err, req, res, next) => { // eslint-disable-line no-unused-vars
   logger.error(`Unhandled error: ${err.message}`);
+  // Check if headers have already been sent before trying to send an error response
+  if (res.headersSent) {
+    return next(err); // Pass error to default handler if headers sent
+  }
   res.status(500).json({ 
     message: 'Internal server error', 
     error: process.env.NODE_ENV === 'development' ? err.message : undefined 

src/config/index.js

@@ -210,6 +210,11 @@ const config = {
    * Parsed custom footer links
    * Set via FOOTER_LINKS in .env (e.g., "Link 1 @ URL1, Link 2 @ URL2")
    */
+  _footerLinksRaw: (() => {
+    const rawValue = process.env.FOOTER_LINKS;
+    console.log(`[CONFIG] Raw FOOTER_LINKS from process.env: '${rawValue}'`); 
+    return rawValue; // Keep the original flow, just log
+  })(),
   footerLinks: parseFooterLinks(process.env.FOOTER_LINKS),
   
   // =====================