Move deduplication to a separate service

lib/services/deduplication_service.dart

@@ -0,0 +1,94 @@
+import 'package:dio/dio.dart';
+import 'package:logging/logging.dart';
+import 'package:photos/core/configuration.dart';
+import 'package:photos/core/errors.dart';
+import 'package:photos/core/network.dart';
+import 'package:photos/db/files_db.dart';
+import 'package:photos/models/duplicate_files.dart';
+import 'package:photos/models/file.dart';
+
+class DeduplicationService {
+  final _logger = Logger("DeduplicationService");
+  final _dio = Network.instance.getDio();
+
+  DeduplicationService._privateConstructor();
+
+  static final DeduplicationService instance =
+      DeduplicationService._privateConstructor();
+
+  Future<List<DuplicateFiles>> getDuplicateFiles() async {
+    try {
+      DuplicateFilesResponse dupes = await _fetchDuplicateFileIDs();
+      final ids = <int>[];
+      for (final dupe in dupes.duplicates) {
+        ids.addAll(dupe.fileIDs);
+      }
+      final fileMap = await FilesDB.instance.getFilesFromIDs(ids);
+      final result = _computeDuplicates(dupes, fileMap);
+      result.sort((a, b) {
+        final aSize = a.files.length * a.size;
+        final bSize = b.files.length * b.size;
+        return bSize - aSize;
+      });
+      return result;
+    } catch (e) {
+      _logger.severe(e);
+      rethrow;
+    }
+  }
+
+  List<DuplicateFiles> _computeDuplicates(
+      DuplicateFilesResponse dupes, Map<int, File> fileMap) {
+    final result = <DuplicateFiles>[];
+    for (final dupe in dupes.duplicates) {
+      final files = <File>[];
+      final Map<int, int> creationTimeCounter = {};
+      int mostFrequentCreationTime = 0, mostFrequentCreationTimeCount = 0;
+      for (final id in dupe.fileIDs) {
+        final file = fileMap[id];
+        if (file != null) {
+          if (creationTimeCounter.containsKey(file.creationTime)) {
+            creationTimeCounter[file.creationTime]++;
+          } else {
+            creationTimeCounter[file.creationTime] = 0;
+          }
+          if (creationTimeCounter[file.creationTime] >
+              mostFrequentCreationTimeCount) {
+            mostFrequentCreationTimeCount =
+                creationTimeCounter[file.creationTime];
+            mostFrequentCreationTime = file.creationTime;
+          }
+          files.add(file);
+        } else {
+          _logger.severe(
+              "Missing file",
+              InvalidStateError(
+                  "Could not find file in local DB " + id.toString()));
+        }
+      }
+      final incorrectDuplicates = <File>{};
+      for (final file in files) {
+        if (file.creationTime != mostFrequentCreationTime) {
+          incorrectDuplicates.add(file);
+        }
+      }
+      files.removeWhere((file) => incorrectDuplicates.contains(file));
+      if (files.length > 1) {
+        result.add(DuplicateFiles(files, dupe.size));
+      }
+    }
+    return result;
+  }
+
+  Future<DuplicateFilesResponse> _fetchDuplicateFileIDs() async {
+    final response = await _dio.get(
+      Configuration.instance.getHttpEndpoint() + "/files/duplicates",
+      options: Options(
+        headers: {
+          "X-Auth-Token": Configuration.instance.getToken(),
+        },
+      ),
+    );
+    return DuplicateFilesResponse.fromMap(response.data);
+  }
+}

lib/services/sync_service.dart

@@ -16,8 +16,6 @@ import 'package:photos/events/subscription_purchased_event.dart';
 import 'package:photos/events/sync_status_update_event.dart';
 import 'package:photos/events/trigger_logout_event.dart';
 import 'package:photos/models/backup_status.dart';
-import 'package:photos/models/duplicate_files.dart';
-import 'package:photos/models/file.dart';
 import 'package:photos/models/file_type.dart';
 import 'package:photos/services/local_sync_service.dart';
 import 'package:photos/services/notification_service.dart';
@@ -185,72 +183,6 @@ class SyncService {
     );
   }
 
-  Future<List<DuplicateFiles>> getDuplicateFiles() async {
-    try {
-      final response = await _dio.get(
-        Configuration.instance.getHttpEndpoint() + "/files/duplicates",
-        options: Options(
-          headers: {
-            "X-Auth-Token": Configuration.instance.getToken(),
-          },
-        ),
-      );
-      final dupes = DuplicateFilesResponse.fromMap(response.data);
-      final ids = <int>[];
-      for (final dupe in dupes.duplicates) {
-        ids.addAll(dupe.fileIDs);
-      }
-      final fileMap = await FilesDB.instance.getFilesFromIDs(ids);
-      final result = <DuplicateFiles>[];
-      for (final dupe in dupes.duplicates) {
-        final files = <File>[];
-        final Map<int, int> creationTimeCounter = {};
-        int mostFrequentCreationTime = 0, mostFrequentCreationTimeCount = 0;
-        for (final id in dupe.fileIDs) {
-          final file = fileMap[id];
-          if (file != null) {
-            if (creationTimeCounter.containsKey(file.creationTime)) {
-              creationTimeCounter[file.creationTime]++;
-            } else {
-              creationTimeCounter[file.creationTime] = 0;
-            }
-            if (creationTimeCounter[file.creationTime] >
-                mostFrequentCreationTimeCount) {
-              mostFrequentCreationTimeCount =
-                  creationTimeCounter[file.creationTime];
-              mostFrequentCreationTime = file.creationTime;
-            }
-            files.add(file);
-          } else {
-            _logger.severe(
-                "Could not find file in local DB",
-                InvalidStateError(
-                    "Could not find file in local DB " + id.toString()));
-          }
-        }
-        final incorrectDuplicates = <File>{};
-        for (final file in files) {
-          if (file.creationTime != mostFrequentCreationTime) {
-            incorrectDuplicates.add(file);
-          }
-        }
-        files.removeWhere((file) => incorrectDuplicates.contains(file));
-        if (files.length > 1) {
-          result.add(DuplicateFiles(files, dupe.size));
-        }
-      }
-      result.sort((a, b) {
-        final aSize = a.files.length * a.size;
-        final bSize = b.files.length * b.size;
-        return bSize - aSize;
-      });
-      return result;
-    } catch (e) {
-      _logger.severe(e);
-      rethrow;
-    }
-  }
-
   Future<BackupStatus> getBackupStatus() async {
     final ids = await FilesDB.instance.getBackedUpIDs();
     final size = await _getFileSize(ids.uploadedIDs);

lib/ui/settings/backup_section_widget.dart

@@ -4,6 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:logging/logging.dart';
 import 'package:photos/core/configuration.dart';
 import 'package:photos/models/backup_status.dart';
+import 'package:photos/services/deduplication_service.dart';
 import 'package:photos/services/sync_service.dart';
 import 'package:photos/ui/backup_folder_selection_page.dart';
 import 'package:photos/ui/deduplicate_page.dart';
@@ -132,7 +133,8 @@ class BackupSectionWidgetState extends State<BackupSectionWidget> {
           onTap: () async {
             final dialog = createProgressDialog(context, "calculating...");
             await dialog.show();
-            final duplicates = await SyncService.instance.getDuplicateFiles();
+            final duplicates =
+                await DeduplicationService.instance.getDuplicateFiles();
             await dialog.hide();
             if (duplicates.isEmpty) {
               showErrorDialog(context, "✨ no duplicates",