Add initial similarity API

This ports over the logic from the CLI into a DRF API view

It's a basic start for now,
but gets at least a working example for local dev.

adserver/analyzer/management/commands/runmodel.py

@@ -45,7 +45,7 @@ def handle_url(self, url):
             self.stdout.write(
                 _("Keywords from '%s': %s") % (backend.__name__, analyzed_keywords)
             )
-            analyzed_embedding = backend.embedding(response)
+            analyzed_embedding = backend_instance.embedding(response)
             self.stdout.write(
                 _("Embeddings from '%s': %s") % (backend.__name__, analyzed_embedding)
             )

adserver/analyzer/views.py

@@ -1 +1,53 @@
-"""Intentionally blank."""
+from django.conf import settings
+from pgvector.django import CosineDistance
+from rest_framework import status
+from rest_framework.response import Response
+from rest_framework.views import APIView
+
+from adserver.analyzer.backends.st import SentenceTransformerAnalyzerBackend
+from adserver.analyzer.models import AnalyzedUrl
+
+
+if "adserver.analyzer" in settings.INSTALLED_APPS:
+
+    class EmbeddingViewSet(APIView):
+        """
+        Returns a list of similar URLs and scores based on querying the AnalyzedURL embedding for an incoming URL.
+
+        .. http:get:: /api/v1/embedding/
+
+            Return a list of similar URLs and scores based on querying the AnalyzedURL embedding for an incoming URL
+
+            :<json string url: **Required**. The URL to query for similar URLs and scores
+
+            :>json int count: The number of similar URLs returned
+            :>json array results: An array of similar URLs and scores
+        """
+
+        def get(self, request):
+            """Return a list of similar URLs and scores based on querying the AnalyzedURL embedding for an incoming URL."""
+            url = request.query_params.get("url")
+
+            if not url:
+                return Response(
+                    {"error": "url is required"}, status=status.HTTP_400_BAD_REQUEST
+                )
+
+            backend_instance = SentenceTransformerAnalyzerBackend(url)
+            response = backend_instance.fetch()
+            processed_text = backend_instance.get_content(response)
+            analyzed_embedding = backend_instance.embedding(response)
+
+            urls = (
+                AnalyzedUrl.objects.exclude(embedding=None)
+                .annotate(distance=CosineDistance("embedding", analyzed_embedding))
+                .order_by("distance")[:10]
+            )
+
+            return Response(
+                {
+                    "count": len(urls),
+                    "text": processed_text[:500],
+                    "results": [[url.url, url.distance] for url in urls],
+                }
+            )

adserver/api/urls.py

@@ -1,4 +1,5 @@
 """API Urls for the ad server."""
+from django.conf import settings
 from django.urls import path
 from rest_framework import routers
 
@@ -14,4 +15,11 @@
 router = routers.SimpleRouter()
 router.register(r"advertisers", AdvertiserViewSet, basename="advertisers")
 router.register(r"publishers", PublisherViewSet, basename="publishers")
+
+if "adserver.analyzer" in settings.INSTALLED_APPS:
+    from adserver.analyzer.views import EmbeddingViewSet
+
+    urlpatterns += [path(r"similar/", EmbeddingViewSet.as_view(), name="similar")]
+
+
 urlpatterns += router.urls

adserver/api/views.py

@@ -37,7 +37,6 @@
 
 
 class AdDecisionView(GeoIpMixin, APIView):
-
     """
     Make a decision on an `Advertisement` to show.
 
@@ -360,7 +359,6 @@ def decision(self, request, data):
 
 
 class AdvertiserViewSet(viewsets.ReadOnlyModelViewSet):
-
     """
     Advertiser API calls.
 
@@ -470,7 +468,6 @@ def report(self, request, slug=None):  # pylint: disable=unused-argument
 
 
 class PublisherViewSet(viewsets.ReadOnlyModelViewSet):
-
     """
     Publisher API calls.