Add an improved backend for the Cause search

backend/donations/views/api.py

@@ -27,7 +27,7 @@
     has_archive_generation_deadline_passed,
     has_recent_archive_job,
 )
-from .common.search import NgoCauseMixedSearchMixin
+from .common.search import CauseSearchMixin
 
 logger = logging.getLogger(__name__)
 
@@ -49,7 +49,7 @@ def post(self, request, *args, **kwargs):
         return redirect_success
 
 
-class SearchCausesApi(TemplateView, NgoCauseMixedSearchMixin):
+class SearchCausesApi(TemplateView, CauseSearchMixin):
     queryset = Cause.public_active
 
     def get(self, request, *args, **kwargs):

backend/donations/views/common/search.py

@@ -15,6 +15,7 @@
 
 from donations.models.donors import Donor
 from donations.models.ngos import Cause, Ngo
+from utils.text.registration_number import probable_registration_number
 
 
 class ConfigureSearch:
@@ -99,7 +100,7 @@ def get_search_results(cls, queryset: QuerySet, query: str, language_code: str)
         return ngos
 
 
-class CauseSearchMixin(CommonSearchMixin):
+class DeprecatedCauseSearchMixin(CommonSearchMixin):
     @classmethod
     def get_search_results(cls, queryset: QuerySet, query: str, language_code: str) -> QuerySet[Cause]:
         search_fields = ["name"]
@@ -126,6 +127,44 @@ def get_search_results(cls, queryset: QuerySet, query: str, language_code: str)
         return causes
 
 
+class CauseSearchMixin(CommonSearchMixin):
+    @classmethod
+    def get_search_results(cls, queryset: QuerySet, query: str, language_code: str) -> QuerySet[Cause]:
+        if settings.ENABLE_CAUSE_SEARCH_EXACT_MATCH:
+            query_filter = Q(name__icontains=query)
+            # If the query looks like a registration number then also try to find the main causes owned by
+            # organisations which have that registration number
+            registration_number = probable_registration_number(query)
+            if registration_number:
+                query_filter = query_filter | (Q(ngo__registration_number=registration_number) & Q(is_main=True))
+
+            exact_causes: QuerySet[Cause] = queryset.filter(query_filter).order_by("id").distinct("id")
+            if exact_causes.count():
+                return exact_causes
+
+        search_vector: SearchVector = ConfigureSearch.vector(("name",), language_code)
+        search_query: SearchQuery = ConfigureSearch.query(query, language_code)
+
+        if settings.ENABLE_CAUSE_SEARCH_WORD_SIMILARITY:
+            trigram_similarity = TrigramWordSimilarity(query, "name")
+            similarity_threshold = 0.4
+        else:
+            trigram_similarity = TrigramSimilarity("name", query)
+            similarity_threshold = 0.3
+
+        fuzzy_causes: QuerySet[Cause] = (
+            queryset.annotate(
+                rank=SearchRank(search_vector, search_query),
+                similarity=trigram_similarity,
+            )
+            .filter(Q(rank__gte=0.3) | Q(similarity__gt=similarity_threshold))
+            .order_by("id")
+            .distinct("id")
+        )
+
+        return fuzzy_causes
+
+
 class NgoCauseMixedSearchMixin(CommonSearchMixin):
     @classmethod
     def get_search_results(cls, queryset: QuerySet, query: str, language_code: str) -> QuerySet[Cause]:

backend/donations/views/site.py

@@ -18,7 +18,7 @@
 from ..models.donors import Donor
 from ..models.ngos import FRONTPAGE_NGOS_KEY, FRONTPAGE_STATS_KEY, Cause
 from .base import BaseVisibleTemplateView
-from .common.search import CauseSearchMixin, NgoCauseMixedSearchMixin
+from .common.search import CauseSearchMixin
 
 logger = logging.getLogger(__name__)
 
@@ -139,7 +139,7 @@ def get_context_data(self, **kwargs):
         return context
 
 
-class NgoListHandler(NgoCauseMixedSearchMixin):
+class NgoListHandler(CauseSearchMixin):
     template_name = "public/all-ngos.html"
     context_object_name = "causes"
     queryset = Cause.public_active

backend/redirectioneaza/settings/feature_flags.py

@@ -4,6 +4,7 @@
 # Search tweaks
 ENABLE_NGO_SEARCH_WORD_SIMILARITY = env.bool("ENABLE_NGO_SEARCH_WORD_SIMILARITY", False)
 ENABLE_CAUSE_SEARCH_WORD_SIMILARITY = env.bool("ENABLE_CAUSE_SEARCH_WORD_SIMILARITY", False)
+ENABLE_CAUSE_SEARCH_EXACT_MATCH = env.bool("ENABLE_CAUSE_SEARCH_EXACT_MATCH", True)
 
 # Feature flags
 ENABLE_FLAG_CONTACT = env.bool("ENABLE_FLAG_CONTACT", False)

backend/utils/text/registration_number.py

@@ -103,3 +103,18 @@ def ngo_id_number_validator(value):
         return
 
     raise ValidationError(_("The ID number is not valid"))
+
+
+def probable_registration_number(query: str) -> str | None:
+    """
+    Try to guess if a query string could be a registration number and return that number
+    """
+    query = query.strip().upper()
+
+    if query.startswith("RO") and query[2:].isnumeric() and len(query) <= 12:
+        return query[2:]
+
+    if query.isnumeric() and len(query) <= 10:
+        return query
+
+    return None