[mob][photos] Curate location filters in isolate

mobile/lib/services/location_service.dart

@@ -42,6 +42,20 @@ class LocationService {
     );
   }
 
+  Future<Map<LocationTag, int>> getLocationTagsToOccurance(
+    List<EnteFile> files,
+  ) async {
+    final locationTagEntities =
+        await LocationService.instance.getLocationTags();
+
+    final locationTagToOccurrence = await _computer.compute(
+      _getLocationTagsToOccurenceForIsolate,
+      param: {"files": files, "locationTagEntities": locationTagEntities},
+    );
+
+    return locationTagToOccurrence;
+  }
+
   Future<Map<City, List<EnteFile>>> getFilesInCity(
     List<EnteFile> allFiles,
     String query,
@@ -230,6 +244,39 @@ class LocationService {
   }
 }
 
+Map<LocationTag, int> _getLocationTagsToOccurenceForIsolate(
+  Map args,
+) {
+  final List<EnteFile> files = args["files"];
+
+  final locationTagToOccurence = <LocationTag, int>{};
+  final locationTagEntities =
+      args["locationTagEntities"] as Iterable<LocalEntity<LocationTag>>;
+
+  for (EnteFile file in files) {
+    if (file.uploadedFileID == null ||
+        file.uploadedFileID == -1 ||
+        !file.hasLocation) continue;
+    for (LocalEntity<LocationTag> locationTagEntity in locationTagEntities) {
+      final locationTag = locationTagEntity.item;
+      final fileCoordinates = file.location!;
+      if (isFileInsideLocationTag(
+        locationTag.centerPoint,
+        fileCoordinates,
+        locationTag.radius,
+      )) {
+        locationTagToOccurence.update(
+          locationTag,
+          (value) => value + 1,
+          ifAbsent: () => 1,
+        );
+      }
+    }
+  }
+
+  return locationTagToOccurence;
+}
+
 Future<List<City>> parseCities(Map args) async {
   final file = File(args["filePath"]);
   final citiesJson = json.decode(await file.readAsString());

mobile/lib/ui/viewer/file_details/location_tags_widget.dart

@@ -104,7 +104,6 @@ class _LocationTagsWidgetState extends State<LocationTagsWidget> {
   }
 
   Future<List<Widget>> _getLocationTags() async {
-    // await Future.delayed(const Duration(seconds: 1));
     final locationTags = await LocationService.instance
         .enclosingLocationTags(widget.file.location!);
     if (locationTags.isEmpty) {

mobile/lib/utils/hierarchical_search_util.dart

@@ -2,10 +2,13 @@ import "package:logging/logging.dart";
 import "package:photos/db/files_db.dart";
 import "package:photos/models/file/file.dart";
 import "package:photos/models/file/file_type.dart";
+import "package:photos/models/location_tag/location_tag.dart";
 import "package:photos/models/search/hierarchical/album_filter.dart";
 import "package:photos/models/search/hierarchical/file_type_filter.dart";
 import "package:photos/models/search/hierarchical/hierarchical_search_filter.dart";
+import "package:photos/models/search/hierarchical/location_filter.dart";
 import "package:photos/services/collections_service.dart";
+import "package:photos/services/location_service.dart";
 import "package:photos/services/search_service.dart";
 import "package:photos/ui/viewer/gallery/state/search_filter_data_provider.dart";
 
@@ -59,11 +62,16 @@ void curateFilters(
         await _curateAlbumFilters(searchFilterDataProvider, files);
     final fileTypeFilters =
         _curateFileTypeFilters(searchFilterDataProvider, files);
+    final locationFilters = await _curateLocationFilters(
+      searchFilterDataProvider,
+      files,
+    );
 
-    searchFilterDataProvider
-        .clearAndAddRecommendations([...albumFilters, ...fileTypeFilters]);
+    searchFilterDataProvider.clearAndAddRecommendations(
+      [...albumFilters, ...locationFilters, ...fileTypeFilters],
+    );
   } catch (e) {
-    Logger("HierarchicalSearchUtil").severe("Failed to curate filters: $e");
+    Logger("HierarchicalSearchUtil").severe("Failed to curate filters", e);
   }
 }
 
@@ -152,3 +160,23 @@ List<FileTypeFilter> _curateFileTypeFilters(
 
   return fileTypeFilters;
 }
+
+Future<List<LocationFilter>> _curateLocationFilters(
+  SearchFilterDataProvider searchFilterDataProvider,
+  List<EnteFile> files,
+) async {
+  final locationFilters = <LocationFilter>[];
+  final locationTagToOccurrence =
+      await LocationService.instance.getLocationTagsToOccurance(files);
+
+  for (LocationTag locationTag in locationTagToOccurrence.keys) {
+    locationFilters.add(
+      LocationFilter(
+        locationTag: locationTag,
+        occurrence: locationTagToOccurrence[locationTag]!,
+      ),
+    );
+  }
+
+  return locationFilters;
+}