add PostgreSQL support and enhance product search functionality

backend/product/views.py

@@ -6,7 +6,9 @@ from .models import *
 from .serializers import *
 from rest_framework import status
 from rest_framework.response import Response
-from django.db.models import Q
+from django.db.models import Q, Value
+from django.db.models.functions import Coalesce
+from django.contrib.postgres.search import TrigramSimilarity
 from django.shortcuts import get_object_or_404
 from rest_framework.permissions import IsAuthenticatedOrReadOnly
 from utils.pagination import StructurePagination
@@ -286,8 +288,12 @@ class AllProductsView(APIView):
             # Search filter
             search_query = request.query_params.get('search')
             if search_query:
-                products = products.filter(Q(name__icontains=search_query) | Q(
-                    description__icontains=search_query))
+                products = products.annotate(
+                    similarity=(
+                        TrigramSimilarity('name', search_query)
+                        + TrigramSimilarity(Coalesce('description', Value('')), search_query)
+                    )
+                ).filter(similarity__gt=0.1)
 
             # Price filters
             price_gte = request.query_params.get('price_gte')
@@ -314,6 +320,8 @@ class AllProductsView(APIView):
             sort_by = request.query_params.get('sort')
             if sort_by in ['name', '-name', 'created_at', '-created_at']:
                 products = products.order_by(sort_by)
+            elif search_query:
+                products = products.order_by('-similarity', 'name')
             else:
                 products = products.order_by('name')