feat(viewsets.py) : add the new viewset LastVisitedUniversityViewSet

Relates to #149

backend/backend_app/viewsets.py

 import logging
 
 from django.conf import settings
+from django.db import connection
+from rest_framework import status
 from rest_framework.permissions import BasePermission
 from rest_framework.response import Response
 from rest_framework.viewsets import ViewSet
@@ -20,6 +22,7 @@ from backend_app.models.file_picture import FileViewSet, PictureViewSet
 from backend_app.models.for_testing.moderation import ForTestingModerationViewSet
 from backend_app.models.for_testing.versioning import ForTestingVersioningViewSet
 from backend_app.models.language import LanguageViewSet
+from backend_app.models.lastVisitedUniversities import LastVisitedUniversity
 from backend_app.models.offer import OfferViewSet
 from backend_app.models.partner import Partner
 from backend_app.models.pendingModeration import (
@@ -35,7 +38,7 @@ from backend_app.models.taggedItems import (
     CountryTaggedItemViewSet,
     UniversityTaggedItemViewSet,
 )
-from backend_app.models.university import UniversityViewSet
+from backend_app.models.university import University, UniversityViewSet
 from backend_app.models.universityDri import UniversityDriViewSet
 from backend_app.models.universityInfo import UniversityInfoViewSet
 from backend_app.models.universityScholarship import UniversityScholarshipViewSet
@@ -346,6 +349,43 @@ class RecommendationListChangeFollowerViewSet(ViewSet):
         return Response(status=200)
 
 
+class LastVisitedUniversityViewSet(ViewSet):
+    """
+    Viewset to update the LastVisitedUniversity model when a user looks at a university
+
+    Doc available here: https://www.django-rest-framework.org/api-guide/viewsets/#viewset-actions
+    """
+
+    end_point_route = "lastVisitedUniversities"
+    permission_classes = (IsAuthenticated,)
+
+    def list(self, request):
+        sql = """
+            SELECT
+                university_id as university,
+                max(ts) AS ts
+            FROM backend_app_lastvisiteduniversity
+            WHERE
+                user_id = %s
+            GROUP BY university_id
+            ORDER BY ts DESC
+            LIMIT 5
+        """
+        with connection.cursor() as cursor:
+            cursor.execute(sql, [request.user.pk])
+            rows = cursor.fetchall()
+            data = [{"university": r[0], "ts": r[1]} for r in rows]
+
+        return Response(data, status=status.HTTP_200_OK)
+
+    def create(self, request):
+        LastVisitedUniversity.objects.create(
+            user=request.user,
+            university=University.objects.get(pk=request.data["university"]),
+        )
+        return Response(status=status.HTTP_201_CREATED)
+
+
 ALL_API_VIEW_VIEWSETS = [
     AppModerationStatusViewSet,
     LatestUpdateExternalDataViewSet,
@@ -355,6 +395,7 @@ ALL_API_VIEW_VIEWSETS = [
     BannedUserViewSet,
     RecommendationListChangeFollowerViewSet,
     DeleteUserViewSet,
+    LastVisitedUniversityViewSet,
 ]
 
 ALL_VIEWSETS = ALL_API_VIEWSETS + ALL_API_VIEW_VIEWSETS