ente/lib/services/ignored_files_service.dart

import 'dart:async';
import 'dart:io';

import 'package:logging/logging.dart';
import 'package:photos/db/ignored_files_db.dart';
import 'package:photos/models/file.dart';
import 'package:photos/models/ignored_file.dart';

class IgnoredFilesService {
  final _logger = Logger("IgnoredFilesService");
  final _db = IgnoredFilesDB.instance;

  IgnoredFilesService._privateConstructor();

  static final IgnoredFilesService instance =
      IgnoredFilesService._privateConstructor();

  Future<Set<String>>? _ignoredIDs;

  Future<Set<String>> get ignoredIDs async {
    // lazily instantiate the db the first time it is accessed
    _ignoredIDs ??= _loadExistingIDs();
    return _ignoredIDs!;
  }

  Future<void> cacheAndInsert(List<IgnoredFile> ignoredFiles) async {
    final existingIDs = await ignoredIDs;
    for (IgnoredFile iFile in ignoredFiles) {
      final id = _idForIgnoredFile(iFile);
      if (id != null) {
        existingIDs.add(id);
      }
    }
    return _db.insertMultiple(ignoredFiles);
  }

  // shouldSkipUpload takes IDs to ignore and file for which it will return
  // whether either true or false. This helper method takes ignoredIDs as input
  // to avoid making it async in nature.
  // This syntax is intentional as we want to ensure that ignoredIDs are loaded
  // from the DB before calling this method.
  bool shouldSkipUpload(Set<String> ignoredIDs, File file) {
    final id = _getIgnoreID(file.localID, file.deviceFolder, file.title);
    if (id != null && id.isNotEmpty) {
      return ignoredIDs.contains(id);
    }
    return false;
  }

  // removeIgnoredMappings is used to remove the ignore mapping for the given
  // set of files so that they can be uploaded.
  Future<void> removeIgnoredMappings(List<File> files) async {
    final List<IgnoredFile> ignoredFiles = [];
    final Set<String> idsToRemoveFromCache = {};
    final Set<String> currentlyIgnoredIDs = await ignoredIDs;
    for (final file in files) {
      // check if upload is not skipped for file. If not, no need to remove
      // any mapping
      if (!shouldSkipUpload(currentlyIgnoredIDs, file)) {
        continue;
      }
      // _shouldSkipUpload checks for null ignoreID
      final id = _getIgnoreID(file.localID, file.deviceFolder, file.title)!;
      idsToRemoveFromCache.add(id);
      ignoredFiles.add(
        IgnoredFile(file.localID, file.title, file.deviceFolder, ""),
      );
    }

    if (ignoredFiles.isNotEmpty) {
      await _db.removeIgnoredEntries(ignoredFiles);
      currentlyIgnoredIDs.removeAll(idsToRemoveFromCache);
    }
  }

  Future<void> reset() async {
    await _db.clearTable();
    _ignoredIDs = null;
  }

  Future<Set<String>> _loadExistingIDs() async {
    _logger.fine('loading existing IDs');
    final dbResult = await _db.getAll();
    final Set<String> result = <String>{};
    for (IgnoredFile iFile in dbResult) {
      final id = _idForIgnoredFile(iFile);
      if (id != null) {
        result.add(id);
      }
    }
    return result;
  }

  String? _idForIgnoredFile(IgnoredFile ignoredFile) {
    return _getIgnoreID(
      ignoredFile.localID,
      ignoredFile.deviceFolder,
      ignoredFile.title,
    );
  }

  String? getIgnoredIDForFile(File file) {
    return _getIgnoreID(
      file.localID,
      file.deviceFolder,
      file.title,
    );
  }

  // _getIgnoreID will return null if don't have sufficient information
  // to ignore the file based on the platform. Uploads from web or files shared to
  // end usually don't have local id.
  // For Android: It returns deviceFolder-title as ID for Android.
  // For iOS, it returns localID as localID is uuid and the title or deviceFolder (aka
  // album name) can be missing due to various reasons.
  String? _getIgnoreID(String? localID, String? deviceFolder, String? title) {
    // file was not uploaded from mobile device
    if (localID == null || localID.isEmpty) {
      return null;
    }
    if (Platform.isAndroid) {
      if (deviceFolder == null || title == null) {
        return null;
      }
      return '$deviceFolder-$title';
    } else {
      return localID;
    }
  }
}