Merge pull request #5 from govtechmy/feat/search-relevancy

feat: enhance search functionality by adding relevance ranking and ad…

Author: shenghann

src/api/views.py

@@ -20,7 +20,7 @@
 from django.utils.decorators import method_decorator
 from django.views.decorators.cache import cache_page
 from django.core.paginator import Paginator, EmptyPage
-from django.contrib.postgres.search import SearchHeadline, SearchQuery
+from django.contrib.postgres.search import SearchHeadline, SearchQuery, SearchRank
 
 from rest_framework.views import APIView
 from rest_framework.response import Response
@@ -462,7 +462,7 @@ class SearchResultsList(APIView):
     Sorted by recency.
     """
 
-    # @method_decorator(cache_page(60 * 60 * 2))
+    @method_decorator(cache_page(60 * 60 * 1))
     def get(self, request) -> JsonResponse:
         filters, window_size, query, _ = handle_search_params(request)
 
@@ -491,10 +491,19 @@ def get(self, request) -> JsonResponse:
                 max_words=window_size,
                 config="english",
             )
-            queryset = queryset.annotate(headline=search_headline)
-            query_values += ["headline"]
+            # Add search ranking for relevance-based ordering
+            search_query = SearchQuery(query, config="english")
+            search_rank = SearchRank(F("speech_vector"), search_query)
+
+            queryset = queryset.annotate(headline=search_headline, rank=search_rank)
+            query_values += ["headline", "rank"]
+            # Order by relevance (rank) first, then by recency as secondary sort
+            queryset = queryset.order_by("-rank", "-sitting__date")
+        else:
+            # For non-search queries, still order by recency
+            queryset = queryset.order_by("-sitting__date")
 
-        queryset = queryset.order_by("-sitting__date").values(*query_values)
+        queryset = queryset.values(*query_values)
         if not queryset:
             return HttpResponseNotFound("No speeches found with the given query.")
 
@@ -523,6 +532,7 @@ def get(self, request) -> JsonResponse:
                         if query
                         else speech["speech"][:window_size] + "..."
                     ),
+                    "relevance_score": speech.get("rank", 0) if query else None,
                     "sitting": {
                         "date": speech["sitting__date"],
                         "term": speech["sitting__cycle__term"],