Display the active language's instrument labels in the first row in the instrument page

web-app/django/VIM/apps/instruments/views/instrument_detail.py

@@ -1,5 +1,6 @@
 from django.views.generic import DetailView
 from VIM.apps.instruments.models import Instrument, Language
+from django.db.models import Case, When, Value
 
 
 class InstrumentDetail(DetailView):
@@ -14,10 +15,35 @@ class InstrumentDetail(DetailView):
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
 
-        # Query the instrument names in all languages
+        # Get the active language
+        active_language_en = self.request.session.get("active_language_en", "English")
+        active_lang = Language.objects.get(en_label=active_language_en)
+        context["active_language"] = active_lang
+
+        # Query the instrument names in all languages, sorted
         instrument_names = (
-            context["instrument"].instrumentname_set.all().select_related("language")
+            context["instrument"]
+            .instrumentname_set.all()
+            .select_related("language")
+            # put 1 in labels in language=active_lang in the active_lang_first field
+            .annotate(
+                active_lang_first=Case(
+                    When(language=active_lang, then=Value(1)),
+                    default=Value(0),
+                )
+            )
+            .order_by(
+                "-active_lang_first",  # active_lang matched names come first
+                "-umil_label",  # the first label is umil_label
+                "pk",  # first added names come first
+            )
         )
+
+        if instrument_names.filter(language=active_lang).exists():
+            context["active_instrument_label"] = instrument_names.first()
+        else:
+            context["active_instrument_label"] = ""
+
         if self.request.user.is_authenticated:
             # Show all names for authenticated users
             context["instrument_names"] = instrument_names.all()
@@ -39,23 +65,6 @@ def get_context_data(self, **kwargs):
                 label_aliases_dict[language]["aliases"].append(instrumentname)
         context["label_aliases_dict"] = label_aliases_dict
 
-        # Get the active language
-        active_language_en = self.request.session.get("active_language_en", None)
-        context["active_language"] = (
-            Language.objects.get(en_label=active_language_en)
-            if active_language_en
-            else Language.objects.get(en_label="English")  # default in English
-        )
-
-        # Get the instrument label in the active language
-        # Set label to the first instrument name added in the language if there is no "umil_label" set
-        active_labels = instrument_names.filter(language=context["active_language"])
-        umil_label = active_labels.filter(umil_label=True)
-        if umil_label.exists():
-            context["active_instrument_label"] = umil_label.first()
-        else:
-            context["active_instrument_label"] = active_labels.first()
-
         # Get all languages for the dropdown
         context["languages"] = Language.objects.all()