Prevent duplicate uploads across collections

lib/db/files_db.dart

@@ -113,6 +113,18 @@ class FilesDB {
     return await batch.commit();
   }
 
+  Future<File> getFile(int generatedID) async {
+    final db = await instance.database;
+    final results = await db.query(table,
+        where: '$columnGeneratedID = ?', whereArgs: [generatedID]);
+    final convertedResults = _convertToFiles(results);
+    if (convertedResults.length == 0) {
+      return null;
+    } else {
+      return convertedResults[1];
+    }
+  }
+
   Future<List<File>> getOwnedFiles(int ownerID) async {
     final db = await instance.database;
     final whereArgs = List<dynamic>();

lib/services/sync_service.dart

@@ -201,24 +201,37 @@ class SyncService {
         file.collectionID = (await CollectionsService.instance
                 .getOrCreateForPath(file.deviceFolder))
             .id;
-        var uploadedFile;
-        if (Configuration.instance.hasOptedForE2E()) {
-          uploadedFile = await _uploader.encryptAndUploadFile(file);
+        final existingFile = await _db.getFile(file.generatedID);
+
+        if (existingFile.uploadedFileID != null) {
+          // The file was uploaded outside this loop
+          // Eg: Addition to an album or favorites
+          await CollectionsService.instance
+              .addToCollection(file.collectionID, [existingFile]);
+        } else if (_uploader.getCurrentUploadStatus(file.generatedID) !=
+            null) {
+          // The file is currently being uploaded outside this loop
+          // Eg: Addition to an album or favorites
+          await _uploader.getCurrentUploadStatus(file.generatedID);
+          await CollectionsService.instance
+              .addToCollection(file.collectionID, [existingFile]);
         } else {
-          uploadedFile = await _uploader.uploadFile(file);
+          // TODO: The file might be currently being uploaded leading to two
+          // deep copies
+          final uploadedFile = await _uploader.encryptAndUploadFile(file);
+          await _db.update(
+            file.generatedID,
+            uploadedFile.uploadedFileID,
+            uploadedFile.ownerID,
+            uploadedFile.collectionID,
+            uploadedFile.updationTime,
+            file.encryptedKey,
+            file.keyDecryptionNonce,
+            file.fileDecryptionHeader,
+            file.thumbnailDecryptionHeader,
+            file.metadataDecryptionHeader,
+          );
         }
-        await _db.update(
-          file.generatedID,
-          uploadedFile.uploadedFileID,
-          uploadedFile.ownerID,
-          uploadedFile.collectionID,
-          uploadedFile.updationTime,
-          file.encryptedKey,
-          file.keyDecryptionNonce,
-          file.fileDecryptionHeader,
-          file.thumbnailDecryptionHeader,
-          file.metadataDecryptionHeader,
-        );
         Bus.instance.fire(PhotoUploadEvent(
             completed: i + 1, total: filesToBeUploaded.length));
       } catch (e) {

lib/utils/file_uploader.dart

@@ -15,10 +15,15 @@ import 'package:photos/utils/file_util.dart';
 class FileUploader {
   final _logger = Logger("FileUploader");
   final _dio = Dio();
+  final _currentlyUploading = Map<int, Future<File>>();
 
   FileUploader._privateConstructor();
   static FileUploader instance = FileUploader._privateConstructor();
 
+  Future<File> getCurrentUploadStatus(int generatedID) {
+    return _currentlyUploading[generatedID];
+  }
+
   Future<UploadURL> getUploadURL() {
     return Dio()
         .get(
@@ -53,6 +58,11 @@ class FileUploader {
   }
 
   Future<File> encryptAndUploadFile(File file) async {
+    _currentlyUploading[file.generatedID] = _encryptAndUploadFile(file);
+    return _currentlyUploading[file.generatedID];
+  }
+
+  Future<File> _encryptAndUploadFile(File file) async {
     _logger.info("Uploading " + file.toString());
     final encryptedFileName = file.generatedID.toString() + ".encrypted";
     final tempDirectory = Configuration.instance.getTempDirectory();
@@ -137,6 +147,7 @@ class FileUploader {
       file.fileDecryptionHeader = fileDecryptionHeader;
       file.thumbnailDecryptionHeader = thumbnailDecryptionHeader;
       file.metadataDecryptionHeader = metadataDecryptionHeader;
+      _currentlyUploading.remove(file.generatedID);
       return file;
     });
   }