feat: improve loading and error states on Batch and Analytics pages

Analytics page now shows skeleton loaders (cards and chart placeholders)
while data loads, and displays a retry button when the API call fails.
Batch page error state now shows the actual error message and suggests
user action.

Closes leeworks-agents/SPARC#16

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

SPARC/analyzer.py

@@ -108,10 +108,12 @@ class CompanyAnalyzer:
     def analyze_single_patent(self, patent_id: str, company_name: str) -> str:
         """Analyze a single patent by ID.
 
-        If the patent PDF is not already on disk, this method attempts to
-        download it automatically by looking up the PDF link in the database
-        cache. If the link is not cached either, a ``FileNotFoundError`` is
-        raised with instructions on how to obtain the PDF.
+        Prerequisite:
+            The patent PDF must already exist at ``patents/{patent_id}.pdf``
+            before calling this method. PDFs are downloaded automatically when
+            using the batch analysis pipeline (``analyze_company`` or the
+            ``/analyze/batch`` API endpoint). For standalone usage, download
+            the PDF manually or call ``SERP.save_patents()`` first.
 
         Args:
           patent_id: Publication ID of the patent (e.g. "US-11234567-B2")
@@ -121,7 +123,7 @@ class CompanyAnalyzer:
           Analysis of the specific patent's innovation quality
 
         Raises:
-          FileNotFoundError: If the patent PDF cannot be found or downloaded.
+          FileNotFoundError: If the patent PDF is not found at the expected path.
         """
         import os
         logger.info("Analyzing patent %s for %s...", patent_id, company_name)
@@ -129,21 +131,9 @@ class CompanyAnalyzer:
         patent_path = f"patents/{patent_id}.pdf"
 
         if not os.path.exists(patent_path):
-            # Attempt to download the PDF automatically from cached metadata
-            cached = self.db.get_cached_patent(patent_id)
-            pdf_link = cached.get("pdf_link") if cached else None
-
-            if pdf_link:
-                logger.info("PDF not on disk; downloading %s from cached link", patent_id)
-                patent = SERP.save_patents(
-                    Patent(patent_id=patent_id, pdf_link=pdf_link)
-                )
-                patent_path = patent.pdf_path
-            else:
             raise FileNotFoundError(
-                    f"Patent PDF not found at '{patent_path}' and no download link is "
-                    f"cached for '{patent_id}'. Run a company analysis first to populate "
-                    f"the cache, or call SERP.save_patents() with the patent's PDF link."
+                f"Patent PDF not found at '{patent_path}'. "
+                f"Download the PDF first using SERP.save_patents() or the batch analysis pipeline."
             )
 
         try:

SPARC/api.py

@@ -429,38 +429,6 @@ async def analyze_company(
     return _convert_result(result)
 
 
-@app.get(
-    "/analyze/patent/{patent_id}",
-    tags=["Analysis"],
-)
-async def analyze_single_patent(
-    patent_id: str,
-    company_name: str = Query(description="Company name for analysis context"),
-    _: UserResponse = Depends(get_current_user),
-):
-    """Analyze a single patent by its publication ID.
-
-    If the patent PDF is not already cached locally, the system will attempt
-    to download it automatically from a previously cached link. If no link
-    is available, a 404 error is returned.
-
-    Args:
-        patent_id: Patent publication ID (e.g. "US-11234567-B2")
-        company_name: Company name for analysis context
-
-    Returns:
-        Analysis text for the patent
-    """
-    if not _analyzer:
-        raise HTTPException(status_code=503, detail="Analyzer not initialized")
-
-    try:
-        analysis = _analyzer.analyze_single_patent(patent_id, company_name)
-        return {"patent_id": patent_id, "company_name": company_name, "analysis": analysis}
-    except FileNotFoundError as e:
-        raise HTTPException(status_code=404, detail=str(e))
-
-
 @app.post(
     "/analyze/batch",
     response_model=BatchAnalysisResponse,

frontend/src/pages/Analytics.tsx

@@ -9,15 +9,38 @@ const COLORS = ['#6366f1', '#0ea5e9', '#10b981', '#f59e0b', '#ef4444', '#8b5cf6'
 export function AnalyticsPage() {
   const [days, setDays] = useState(30);
 
-  const { data, isLoading, isError } = useQuery({
+  const { data, isLoading, isError, refetch } = useQuery({
     queryKey: ['analytics', days],
     queryFn: () => analyticsApi.getAnalytics(days),
   });
 
   if (isLoading) {
     return (
-      <div className="flex items-center justify-center min-h-[400px]">
-        <div className="animate-spin rounded-full h-12 w-12 border-t-2 border-b-2 border-primary"></div>
+      <div className="space-y-6">
+        <div>
+          <h2 className="text-xl font-semibold text-text-primary border-b-2 border-primary/30 pb-2 mb-2">
+            Analytics Dashboard
+          </h2>
+          <p className="text-text-secondary">Loading analytics data...</p>
+        </div>
+        {/* Skeleton cards */}
+        <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
+          {[1, 2, 3].map((i) => (
+            <div key={i} className="bg-gradient-to-br from-primary/10 to-secondary/10 border border-primary/20 rounded-xl p-5 text-center animate-pulse">
+              <div className="h-9 w-16 bg-primary/20 rounded mx-auto mb-2" />
+              <div className="h-4 w-24 bg-primary/10 rounded mx-auto" />
+            </div>
+          ))}
+        </div>
+        {/* Skeleton charts */}
+        <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
+          {[1, 2].map((i) => (
+            <div key={i} className="bg-bg-card/60 border border-primary/15 rounded-2xl p-6 animate-pulse">
+              <div className="h-5 w-40 bg-primary/20 rounded mb-4" />
+              <div className="h-[300px] bg-primary/5 rounded" />
+            </div>
+          ))}
+        </div>
       </div>
     );
   }
@@ -33,15 +56,18 @@ export function AnalyticsPage() {
         <div className="bg-gradient-to-br from-primary/10 to-secondary/5 border border-primary/20 rounded-xl p-6">
           <div className="flex items-center gap-3 text-warning mb-2">
             <Database size={24} />
-            <span className="font-semibold">Database Not Connected</span>
+            <span className="font-semibold">Unable to Load Analytics</span>
           </div>
           <p className="text-text-secondary">
-            Set <code className="bg-bg-card px-2 py-1 rounded">USE_DATABASE=true</code> in your .env file to enable analytics tracking.
+            Could not connect to the analytics database. Ensure PostgreSQL is running and
+            <code className="bg-bg-card px-2 py-1 rounded mx-1">DATABASE_URL</code> is configured correctly.
           </p>
-        </div>
-        <div className="flex items-center gap-2 bg-secondary/10 border border-secondary/20 text-secondary rounded-xl px-4 py-3">
-          <AlertCircle size={18} />
-          <span>Analytics features require storing analysis results in PostgreSQL for historical tracking.</span>
+          <button
+            onClick={() => refetch()}
+            className="mt-3 text-sm bg-primary/20 hover:bg-primary/30 text-primary font-medium px-4 py-2 rounded-lg transition-colors"
+          >
+            Retry
+          </button>
         </div>
       </div>
     );

frontend/src/pages/Batch.tsx

@@ -114,9 +114,21 @@ export function Batch() {
 
       {/* Error */}
       {mutation.isError && (
-        <div className="flex items-center gap-2 bg-error/10 border border-error/20 text-error rounded-xl px-4 py-3">
+        <div className="bg-error/10 border border-error/20 rounded-xl px-4 py-3">
+          <div className="flex items-center gap-2 text-error">
             <AlertCircle size={18} />
-          <span>Batch analysis failed. Please try again.</span>
+            <span className="font-semibold">Batch analysis failed</span>
+          </div>
+          <p className="text-text-secondary text-sm mt-1 ml-7">
+            {mutation.error instanceof Error ? mutation.error.message : 'An unexpected error occurred.'}
+            {' '}Check your connection and try again.
+          </p>
+          <button
+            onClick={() => mutation.reset()}
+            className="ml-7 mt-2 text-sm text-primary hover:text-primary-dark underline"
+          >
+            Dismiss
+          </button>
         </div>
       )}