[mob] Debug option to get clusters of blur values

mobile/lib/face/db.dart

@@ -364,6 +364,20 @@ class FaceMLDataDB {
     return maps.map((e) => e[faceBlur] as double).toSet();
   }
 
+  Future<Map<String, double>> getFaceIDsToBlurValues(
+    int maxBlurValue,
+  ) async {
+    final db = await instance.sqliteAsyncDB;
+    final List<Map<String, dynamic>> maps = await db.getAll(
+      'SELECT $faceIDColumn, $faceBlur FROM $facesTable WHERE $faceBlur < $maxBlurValue AND $faceBlur > 1 ORDER BY $faceBlur ASC',
+    );
+    final Map<String, double> result = {};
+    for (final map in maps) {
+      result[map[faceIDColumn] as String] = map[faceBlur] as double;
+    }
+    return result;
+  }
+
   Future<Map<String, int?>> getFaceIdsToClusterIds(
     Iterable<String> faceIds,
   ) async {

mobile/lib/services/machine_learning/face_ml/feedback/cluster_feedback.dart

@@ -295,6 +295,38 @@ class ClusterFeedbackService {
     return clusterIdToFaceIds;
   }
 
+  /// WARNING: this method is purely for debugging purposes, never use in production
+  Future<void> createFakeClustersByBlurValue() async {
+    try {
+      // Delete old clusters
+      await FaceMLDataDB.instance.resetClusterIDs();
+      await FaceMLDataDB.instance.dropClustersAndPersonTable();
+      final List<PersonEntity> persons =
+          await PersonService.instance.getPersons();
+      for (final PersonEntity p in persons) {
+        await PersonService.instance.deletePerson(p.remoteID);
+      }
+
+      // Create new fake clusters based on blur value. One for values between 0 and 10, one for 10-20, etc till 200
+      final int startClusterID = DateTime.now().microsecondsSinceEpoch;
+      final faceIDsToBlurValues =
+          await FaceMLDataDB.instance.getFaceIDsToBlurValues(200);
+      final faceIdToCluster = <String, int>{};
+      for (final entry in faceIDsToBlurValues.entries) {
+        final faceID = entry.key;
+        final blurValue = entry.value;
+        final newClusterID = startClusterID + blurValue ~/ 10;
+        faceIdToCluster[faceID] = newClusterID;
+      }
+      await FaceMLDataDB.instance.updateClusterIdToFaceId(faceIdToCluster);
+
+      Bus.instance.fire(PeopleChangedEvent());
+    } catch (e, s) {
+      _logger.severe("Error in createFakeClustersByBlurValue", e, s);
+      rethrow;
+    }
+  }
+
   Future<void> debugLogClusterBlurValues(
     int clusterID, {
     int? clusterSize,

mobile/lib/ui/settings/debug/face_debug_section_widget.dart

@@ -8,6 +8,7 @@ import "package:photos/events/people_changed_event.dart";
 import "package:photos/face/db.dart";
 import "package:photos/face/model/person.dart";
 import 'package:photos/services/machine_learning/face_ml/face_ml_service.dart';
+import "package:photos/services/machine_learning/face_ml/feedback/cluster_feedback.dart";
 import "package:photos/services/machine_learning/face_ml/person/person_service.dart";
 import 'package:photos/theme/ente_theme.dart';
 import 'package:photos/ui/components/captioned_text_widget.dart';
@@ -284,6 +285,34 @@ class _FaceDebugSectionWidgetState extends State<FaceDebugSectionWidget> {
           },
         ),
         sectionOptionSpacing,
+        MenuItemWidget(
+          captionedTextWidget: const CaptionedTextWidget(
+            title: "Rank blurs",
+          ),
+          pressedColor: getEnteColorScheme(context).fillFaint,
+          trailingIcon: Icons.chevron_right_outlined,
+          trailingIconIsMuted: true,
+          onTap: () async {
+            await showChoiceDialog(
+              context,
+              title: "Are you sure?",
+              body:
+                  "This will delete all clusters and put blurry faces in separate clusters per ten points.",
+              firstButtonLabel: "Yes, confirm",
+              firstButtonOnTap: () async {
+                try {
+                  await ClusterFeedbackService.instance
+                      .createFakeClustersByBlurValue();
+                  showShortToast(context, "Done");
+                } catch (e, s) {
+                  _logger.warning('Failed to rank faces on blur values ', e, s);
+                  await showGenericErrorDialog(context: context, error: e);
+                }
+              },
+            );
+          },
+        ),
+        sectionOptionSpacing,
         MenuItemWidget(
           captionedTextWidget: const CaptionedTextWidget(
             title: "Drop embeddings & feedback",