Medicines: replace in-memory search with pg full text search with GIN index

care/facility/api/viewsets/prescription.py

@@ -1,19 +1,20 @@
-from re import IGNORECASE
-
 from django.shortcuts import get_object_or_404
 from django_filters import rest_framework as filters
 from drf_spectacular.utils import extend_schema
 from rest_framework import mixins, status
 from rest_framework.decorators import action
+from rest_framework.filters import SearchFilter
 from rest_framework.permissions import IsAuthenticated
 from rest_framework.response import Response
-from rest_framework.viewsets import GenericViewSet, ViewSet
+from rest_framework.viewsets import GenericViewSet
 
 from care.facility.api.serializers.prescription import (
+    MedibaseMedicineSerializer,
     MedicineAdministrationSerializer,
     PrescriptionSerializer,
 )
 from care.facility.models import (
+    MedibaseMedicine,
     MedicineAdministration,
     Prescription,
     PrescriptionType,
@@ -136,52 +137,14 @@ def administer(self, request, *args, **kwargs):
     #     return Response({"success": True}, status=status.HTTP_200_OK)
 
 
-class MedibaseViewSet(ViewSet):
+class MedicineViewSet(
+    mixins.ListModelMixin,
+    mixins.RetrieveModelMixin,
+    GenericViewSet,
+):
+    serializer_class = MedibaseMedicineSerializer
     permission_classes = (IsAuthenticated,)
-
-    def serailize_data(self, objects):
-        result = []
-        for object in objects:
-            if type(object) == tuple:
-                object = object[0]
-            result.append(
-                {
-                    "id": object.external_id,
-                    "name": object.name,
-                    "type": object.type,
-                    "generic": object.generic,
-                    "company": object.company,
-                    "contents": object.contents,
-                    "cims_class": object.cims_class,
-                    "atc_classification": object.atc_classification,
-                }
-            )
-        return result
-
-    def sort(self, query, results):
-        exact_matches = []
-        partial_matches = []
-
-        for result in results:
-            if type(result) == tuple:
-                result = result[0]
-            words = result.searchable.lower().split()
-            if query in words:
-                exact_matches.append(result)
-            else:
-                partial_matches.append(result)
-
-        return exact_matches + partial_matches
-
-    def list(self, request):
-        from care.facility.static_data.medibase import MedibaseMedicineTable
-
-        queryset = MedibaseMedicineTable
-
-        if request.GET.get("query", False):
-            query = request.GET.get("query").strip().lower()
-            queryset = queryset.where(
-                searchable=queryset.re_match(r".*" + query + r".*", IGNORECASE)
-            )
-            queryset = self.sort(query, queryset)
-        return Response(self.serailize_data(queryset[:15]))
+    queryset = MedibaseMedicine.objects.all()
+    lookup_field = "external_id"
+    filter_backends = (SearchFilter,)
+    search_fields = ("name", "generic", "company", "contents", "cims_class")

care/facility/migrations/0371_medibasemedicine_search_idx.py

@@ -0,0 +1,22 @@
+# Generated by Django 4.2.2 on 2023-07-06 11:18
+
+import django.contrib.postgres.indexes
+from django.contrib.postgres.operations import BtreeGinExtension
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("facility", "0370_merge_20230705_1500"),
+    ]
+
+    operations = [
+        BtreeGinExtension(),
+        migrations.AddIndex(
+            model_name="medibasemedicine",
+            index=django.contrib.postgres.indexes.GinIndex(
+                fields=["name", "generic", "company", "contents", "cims_class"],
+                name="search_idx",
+            ),
+        ),
+    ]

care/facility/models/prescription.py

@@ -1,5 +1,6 @@
 import enum
 
+from django.contrib.postgres.indexes import GinIndex
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.db.models import JSONField
@@ -66,6 +67,14 @@ class MedibaseMedicine(BaseModel):
     def __str__(self):
         return " - ".join([self.name, self.generic, self.company])
 
+    class Meta:
+        indexes = [
+            GinIndex(
+                fields=["name", "generic", "company", "contents", "cims_class"],
+                name="search_idx",
+            )
+        ]
+
 
 class Prescription(BaseModel):
     consultation = models.ForeignKey(

config/api_router.py

@@ -52,8 +52,8 @@
 from care.facility.api.viewsets.patient_sample import PatientSampleViewSet
 from care.facility.api.viewsets.prescription import (
     ConsultationPrescriptionViewSet,
-    MedibaseViewSet,
     MedicineAdministrationViewSet,
+    MedicineViewSet,
 )
 from care.facility.api.viewsets.prescription_supplier import (
     PrescriptionSupplierConsultationViewSet,
@@ -200,7 +200,7 @@
 consultation_nested_router.register(
     r"prescription_administration", MedicineAdministrationViewSet
 )
-router.register("medibase", MedibaseViewSet, basename="medibase")
+router.register("medicine", MedicineViewSet)
 
 # HCX
 router.register("hcx/policy", PolicyViewSet)