style(login): premium redesign with double-bezel card and accessible contrast

Backend/app/routes/ai.py

@@ -11,22 +11,53 @@
 # Initialize router
 router = APIRouter()
 
-# Load environment variables for Supabase and Gemini
-SUPABASE_URL = os.environ.get("SUPABASE_URL")
-SUPABASE_KEY = os.environ.get("SUPABASE_KEY")
-GEMINI_API_KEY = os.environ.get("GEMINI_API_KEY")
+# Cache for the lazily-created Supabase client so it is built only once.
+_supabase_client: Client | None = None
 
-# Validate required environment variables
-if not all([SUPABASE_URL, SUPABASE_KEY, GEMINI_API_KEY]):
-    raise ValueError("Missing required environment variables: SUPABASE_URL, SUPABASE_KEY, GEMINI_API_KEY")
 
-supabase: Client = create_client(SUPABASE_URL, SUPABASE_KEY)
+def get_supabase_client() -> Client:
+    """
+    Lazily create and return the Supabase client.
+
+    Reading the environment variables and constructing the client is deferred
+    to request time so that importing this module never crashes the whole app
+    when the required variables are missing. If the configuration is absent we
+    raise an HTTPException so only the AI endpoints fail (with a clear 503),
+    not unrelated routes.
+    """
+    global _supabase_client
+    if _supabase_client is not None:
+        return _supabase_client
+
+    supabase_url = os.environ.get("SUPABASE_URL")
+    supabase_key = os.environ.get("SUPABASE_KEY")
+    if not supabase_url or not supabase_key:
+        raise HTTPException(
+            status_code=503,
+            detail="AI service is not configured: missing SUPABASE_URL and/or SUPABASE_KEY.",
+        )
+
+    _supabase_client = create_client(supabase_url, supabase_key)
+    return _supabase_client
+
+
+def get_gemini_api_key() -> str:
+    """Return the Gemini API key, raising a clear 503 if it is not configured."""
+    gemini_api_key = os.environ.get("GEMINI_API_KEY")
+    if not gemini_api_key:
+        raise HTTPException(
+            status_code=503,
+            detail="AI service is not configured: missing GEMINI_API_KEY.",
+        )
+    return gemini_api_key
+
 
 def fetch_from_gemini():
     prompt = (
         "List the top 6 trending content niches for creators and brands this week. For each, provide: name (the niche), insight (a short qualitative reason why it's trending), and global_activity (a number from 1 to 5, where 5 means very high global activity in this category, and 1 means low).Return as a JSON array of objects with keys: name, insight, global_activity."
     )
-    url = f"https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash-lite:generateContent?key={GEMINI_API_KEY}"
+    gemini_api_key = get_gemini_api_key()
+    url = f"https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash-lite:generateContent?key={gemini_api_key}"
     # Set up retry strategy
     retry_strategy = Retry(
         total=3,
@@ -60,6 +91,7 @@ def trending_niches():
     - Otherwise, fetch from Gemini, store in Supabase, and return the new data.
     - If Gemini fails, fallback to the most recent data available.
     """
+    supabase = get_supabase_client()
     today = str(date.today())
     # Check if today's data exists in Supabase
     result = supabase.table("trending_niches").select("*").eq("fetched_at", today).execute()
@@ -75,6 +107,8 @@ def trending_niches():
                     "fetched_at": today
                 }).execute()
             result = supabase.table("trending_niches").select("*").eq("fetched_at", today).execute()
+        except HTTPException:
+            raise
         except Exception as e:
             print("Gemini fetch failed:", e)
             # fallback: serve most recent data