fix: update caching logic and response headers for catalog retrieval

Author: TimilsinaBimal

app/api/endpoints/catalogs.py

@@ -64,7 +64,9 @@ async def get_catalog(type: str, id: str, response: Response, token: str):
         cleaned = [m for m in cleaned if m is not None]
 
         data = {"metas": cleaned}
-        await redis_service.set(catalog_key, json.dumps(data), settings.CATALOG_CACHE_TTL)
+        # if catalog data is not empty, set the cache
+        if cleaned:
+            await redis_service.set(catalog_key, json.dumps(data), settings.CATALOG_CACHE_TTL)
         return data
 
     except HTTPException:

app/services/recommendation/catalog_service.py

@@ -113,7 +113,7 @@ async def get_catalog(
             logger.info(f"Returning {len(recommendations)} items for {content_type}")
 
             # Prepare response headers
-            headers = {"Cache-Control": "public, max-age=21600"}  # 6 hours
+            headers = {"Cache-Control": f"public, max-age={settings.CATALOG_CACHE_TTL}"}
 
             return recommendations, headers