feat: Vercel serverless proxy for Dropbox (fix deploy issues) && update App.tsx

App.tsx

@@ -61,22 +61,16 @@ const App: React.FC = () => {
         directUrl = urlObject.toString();
       }
 
-      let fetchUrl = directUrl;
 
-      // Check if we are in a local environment to use the Vite proxy
-      const isLocal = window.location.hostname === 'localhost' || window.location.hostname === '127.0.0.1';
+      // Unified Fetch Logic for Local (Vite) and Production (Vercel Function)
+      // Both environments now support the /api/dropbox/... path.
+      // - Local: Vite proxies /api/dropbox -> https://www.dropbox.com
+      // - Vercel: api/dropbox.js handles the request -> https://www.dropbox.com
 
-      if (isLocal && url.includes('dropbox.com')) {
-        // Extract path and query from the direct URL
-        const urlObj = new URL(directUrl);
-        // Pass the necessary query params including st and dl=1
-        const searchParams = urlObj.search;
-        fetchUrl = `/api/dropbox${urlObj.pathname}${searchParams}`;
-      } else {
-        // Production or non-local fallback: Use CORS proxy
-        // Using allorigins.win as a fallback if not local
-        fetchUrl = `https://api.allorigins.win/raw?url=${encodeURIComponent(directUrl)}`;
-      }
+      const urlObj = new URL(directUrl);
+      const searchParams = urlObj.search;
+      // Construct path relative to root: /api/dropbox/scl/fi/...
+      const fetchUrl = `/api/dropbox${urlObj.pathname}${searchParams}`;
 
       const response = await fetch(fetchUrl);
       if (!response.ok) throw new Error(`Failed to fetch CSV from URL: ${response.status} ${response.statusText}`);

api/dropbox.ts

@@ -0,0 +1,53 @@
+import type { VercelRequest, VercelResponse } from '@vercel/node';
+
+export default async function handler(req: VercelRequest, res: VercelResponse) {
+    // Allow CORS
+    res.setHeader('Access-Control-Allow-Credentials', 'true');
+    res.setHeader('Access-Control-Allow-Origin', '*');
+    res.setHeader('Access-Control-Allow-Methods', 'GET,OPTIONS,PATCH,DELETE,POST,PUT');
+    res.setHeader(
+        'Access-Control-Allow-Headers',
+        'X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5, Content-Type, Date, X-Api-Version'
+    );
+
+    if (req.method === 'OPTIONS') {
+        res.status(200).end();
+        return;
+    }
+
+    try {
+        // 1. Reconstruct the Target Dropbox URL
+        // The incoming request is to /api/dropbox/scl/fi/...
+        // We want to fetch https://www.dropbox.com/scl/fi/...
+
+        // req.url in Vercel function might be just the suffix or full path depending on routing
+        // Typically: /api/dropbox/scl/fi/xyz?dl=1
+
+        // We need to strip '/api/dropbox' from the start to get the dropbox path
+        const requestPath = req.url || '';
+        const dropboxPath = requestPath.replace(/^\/api\/dropbox/, ''); // e.g. /scl/fi/xyz?dl=1
+
+        const targetUrl = `https://www.dropbox.com${dropboxPath}`;
+
+        console.log(`Proxying to: ${targetUrl}`);
+
+        const response = await fetch(targetUrl);
+
+        if (!response.ok) {
+            throw new Error(`Dropbox responded with ${response.status} ${response.statusText}`);
+        }
+
+        // Forward the content type (likely text/csv)
+        const contentType = response.headers.get('content-type');
+        if (contentType) {
+            res.setHeader('Content-Type', contentType);
+        }
+
+        const data = await response.text();
+        res.status(200).send(data);
+
+    } catch (error) {
+        console.error('Proxy Error:', error);
+        res.status(500).json({ error: 'Failed to fetch data from Dropbox' });
+    }
+}

package.json

@@ -9,15 +9,16 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "@google/genai": "^1.30.0",
+    "papaparse": "^5.5.3",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
-    "@google/genai": "^1.30.0",
     "recharts": "^3.5.0",
-    "xlsx": "^0.18.5",
-    "papaparse": "^5.5.3"
+    "xlsx": "^0.18.5"
   },
   "devDependencies": {
     "@types/node": "^22.14.0",
+    "@vercel/node": "^5.5.22",
     "@vitejs/plugin-react": "^5.0.0",
     "typescript": "~5.8.2",
     "vite": "^6.2.0"