update caching on homepage, and add db checks to healthcheck

home/views.py

@@ -12,6 +12,7 @@ from django.http import HttpResponseRedirect
 import logging
 from django.views import View
 from django.http import HttpResponse
+import contextlib
 
 logger = logging.getLogger(__name__)
 
@@ -31,46 +32,54 @@ class HomePageView(TemplateView):
             
             # Recent Offers
             try:
-                recent_offers_qs = base_offer_qs.order_by("-created_at")
-                context["recent_offers"] = recent_offers_qs[:6]
+                recent_offers_qs = base_offer_qs.order_by("-created_at")[:6]
+                context["recent_offers"] = recent_offers_qs
+                context["cache_key_recent_offers"] = f"recent_offers_{recent_offers_qs.values_list('pk', 'updated_at')}"
             except Exception as e:
                 logger.error(f"Error fetching recent offers: {str(e)}")
                 context["recent_offers"] = []
+                context["cache_key_recent_offers"] = "recent_offers_error"
             
             # Most Offered Cards
             try:
-                context["most_offered_cards"] = (
+                most_offered_cards_qs = (
                     Card.objects.filter(tradeofferhavecard__isnull=False).filter(rarity_level__lte=5)
                     .annotate(offer_count=Sum("tradeofferhavecard__quantity"))
                     .order_by("-offer_count")[:6]
                 )
+                context["most_offered_cards"] = most_offered_cards_qs
+                context["cache_key_most_offered_cards"] = f"most_offered_cards_{most_offered_cards_qs.values_list('pk', 'updated_at')}"
             except Exception as e:
                 logger.error(f"Error fetching most offered cards: {str(e)}")
                 context["most_offered_cards"] = []
-            
+                context["cache_key_most_offered_cards"] = "most_offered_cards_error"
             # Most Wanted Cards
             try:
-                context["most_wanted_cards"] = (
+                most_wanted_cards_qs = (
                     Card.objects.filter(tradeofferwantcard__isnull=False).filter(rarity_level__lte=5)
                     .annotate(offer_count=Sum("tradeofferwantcard__quantity"))
                     .order_by("-offer_count")[:6]
                 )
+                context["most_wanted_cards"] = most_wanted_cards_qs
+                context["cache_key_most_wanted_cards"] = f"most_wanted_cards_{most_wanted_cards_qs.values_list('pk', 'updated_at')}"
             except Exception as e:
                 logger.error(f"Error fetching most wanted cards: {str(e)}")
                 context["most_wanted_cards"] = []
             
             # Least Offered Cards
             try:
-                context["least_offered_cards"] = (
+                least_offered_cards_qs = (
                     Card.objects.filter(rarity_level__lte=5).annotate(
                         offer_count=Coalesce(Sum("tradeofferhavecard__quantity"), 0)
                     )
                     .order_by("offer_count")[:6]
                 )
+                context["least_offered_cards"] = least_offered_cards_qs
+                context["cache_key_least_offered_cards"] = f"least_offered_cards_{least_offered_cards_qs.values_list('pk', 'updated_at')}"
             except Exception as e:
                 logger.error(f"Error fetching least offered cards: {str(e)}")
                 context["least_offered_cards"] = []
-            
+                context["cache_key_least_offered_cards"] = "least_offered_cards_error"
             # Build featured offers with custom ordering
             featured = OrderedDict()
             # Featured "All" offers remains fixed at the top
@@ -100,10 +109,22 @@ class HomePageView(TemplateView):
                 logger.error(f"Error processing rarity-based featured offers: {str(e)}")
 
             context["featured_offers"] = featured
+            # Generate a cache key based on the pks and updated_at timestamps of all featured offers
+            all_offer_identifiers = []
+            for section_name,section_offers in featured.items():
+                # featured_section is a QuerySet. Fetch (pk, updated_at) tuples.
+                identifiers = section_offers.values_list('pk', 'updated_at')
+                # Format each tuple as "pk_timestamp" and add to the list
+                section_strings = [f"{section_name}_{pk}_{ts.timestamp()}" for pk, ts in identifiers]
+                all_offer_identifiers.extend(section_strings)
+            
+            # Join all identifiers into a single string, sorted for consistency regardless of order
+            combined_identifiers = "|".join(sorted(all_offer_identifiers))
+            context["cache_key_featured_offers"] = f"featured_offers_{combined_identifiers}"
         except Exception as e:
             logger.error(f"Unhandled error in HomePageView.get_context_data: {str(e)}")
             # Provide fallback empty data
-            context["cards"] = []
+            context["cards"] = None
             context["recent_offers"] = []
             context["most_offered_cards"] = []
             context["most_wanted_cards"] = []
@@ -118,4 +139,27 @@ class HomePageView(TemplateView):
 
 class HealthCheckView(View):
     def get(self, request, *args, **kwargs):
+
+        try:
+            from django.db import connection
+            connection.cursor().execute("SELECT 1")
+        except Exception as e:
+            return HttpResponse("Database connection failed", status=500)
+
+        try:
+            from trades.models import TradeOffer
+            with contextlib.redirect_stdout(None):
+                print(TradeOffer.objects.count())
+        except Exception as e:
+            return HttpResponse("DB models not reachable, but db is reachable", status=500)
+        
+        try:
+            from django.core.cache import cache
+            cache.set("test", "test")
+            with contextlib.redirect_stdout(None):
+                print(cache.get("test"))
+        except Exception as e:
+            return HttpResponse("Cache not reachable", status=500)
+        
+        logger.info("OK/HEALTHY")
         return HttpResponse("OK/HEALTHY")