Fix 401 error: Add authenticated API proxy for private datasets

src/utils/apiHelpers.ts

@@ -0,0 +1,64 @@
+/**
+ * Helper functions for API calls
+ * Handles both server-side and client-side URL construction
+ */
+
+import { headers } from 'next/headers';
+
+/**
+ * Get the base URL for API calls
+ * For server-side, we need absolute URLs
+ * For client-side, we can use relative URLs
+ */
+export async function getApiBaseUrl(): Promise<string> {
+  // Server-side: need absolute URL
+  if (typeof window === 'undefined') {
+    try {
+      // Use Next.js headers to get the host
+      const headersList = await headers();
+      const host = headersList.get('host');
+      const protocol = headersList.get('x-forwarded-proto') || 'https';
+      
+      if (host) {
+        return `${protocol}://${host}`;
+      }
+    } catch (error) {
+      // headers() might not be available in all contexts
+      // Fall through to environment variables
+    }
+    
+    // Fallback: try environment variables
+    const spaceUrl = 
+      process.env.SPACE_URL || 
+      process.env.NEXT_PUBLIC_APP_URL ||
+      process.env.VERCEL_URL ||
+      process.env.HF_SPACE_URL;
+    
+    if (spaceUrl) {
+      // Ensure it has protocol
+      if (spaceUrl.startsWith('http://') || spaceUrl.startsWith('https://')) {
+        // Remove trailing slash
+        return spaceUrl.endsWith('/') ? spaceUrl.slice(0, -1) : spaceUrl;
+      }
+      return `https://${spaceUrl}`;
+    }
+    
+    // Last resort: use relative URL (Next.js should handle this for same-origin)
+    return '';
+  }
+  
+  // Client-side: use relative URL (empty string)
+  return '';
+}
+
+/**
+ * Build proxy URL for Hugging Face requests
+ * Automatically handles server-side vs client-side
+ * Note: This is async because getApiBaseUrl() is async (needed for server-side)
+ */
+export async function buildProxyUrl(targetUrl: string): Promise<string> {
+  const apiBase = await getApiBaseUrl();
+  const encodedUrl = encodeURIComponent(targetUrl);
+  return `${apiBase}/api/hf-proxy?url=${encodedUrl}`;
+}
+