feat: Implement importing/exporting data

lib/src/ui/bloc/anime_list_bloc.dart

@@ -3,6 +3,7 @@ import 'package:anitrack/src/data/manga.dart';
 import 'package:anitrack/src/data/type.dart';
 import 'package:anitrack/src/service/database.dart';
 import 'package:bloc/bloc.dart';
+import 'package:collection/collection.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:get_it/get_it.dart';
 
@@ -63,7 +64,16 @@ class AnimeListBloc extends Bloc<AnimeListEvent, AnimeListState> {
     await GetIt.I.get<DatabaseService>().addAnime(event.data);
 
     // Add it to the cache
-    _animes.add(event.data);
+    if (event.checkIfExists) {
+      final shouldAdd =
+          _animes.firstWhereOrNull((element) => element.id == event.data.id) ==
+              null;
+      if (shouldAdd) {
+        _animes.add(event.data);
+      }
+    } else {
+      _animes.add(event.data);
+    }
 
     emit(
       state.copyWith(
@@ -80,7 +90,17 @@ class AnimeListBloc extends Bloc<AnimeListEvent, AnimeListState> {
     await GetIt.I.get<DatabaseService>().addManga(event.data);
 
     // Add it to the cache
-    _mangas.add(event.data);
+    // Add it to the cache
+    if (event.checkIfExists) {
+      final shouldAdd =
+          _mangas.firstWhereOrNull((element) => element.id == event.data.id) ==
+              null;
+      if (shouldAdd) {
+        _mangas.add(event.data);
+      }
+    } else {
+      _mangas.add(event.data);
+    }
 
     emit(
       state.copyWith(

lib/src/ui/bloc/anime_list_event.dart

@@ -17,10 +17,14 @@ class AnimeEpisodeDecrementedEvent extends AnimeListEvent {
 }
 
 class AnimeAddedEvent extends AnimeListEvent {
-  AnimeAddedEvent(this.data);
+  AnimeAddedEvent(this.data, {this.checkIfExists = false});
 
   /// The anime to add.
   final AnimeTrackingData data;
+
+  /// If true, checks if the anime with the id is already in the list.
+  /// If it is, does nothing.
+  final bool checkIfExists;
 }
 
 /// Triggered when animes are to be loaded from the database
@@ -59,10 +63,14 @@ class AnimeRemovedEvent extends AnimeListEvent {
 }
 
 class MangaAddedEvent extends AnimeListEvent {
-  MangaAddedEvent(this.data);
+  MangaAddedEvent(this.data, {this.checkIfExists = false});
 
   /// The manga to add.
   final MangaTrackingData data;
+
+  /// If true, checks if the manga with the id is already in the list.
+  /// If it is, does nothing.
+  final bool checkIfExists;
 }
 
 /// Triggered when the manga filter is changed

lib/src/ui/bloc/settings_bloc.dart

@@ -1,19 +1,25 @@
 import 'dart:async';
 import 'dart:convert';
+import 'dart:io';
+import 'package:anitrack/i18n/strings.g.dart';
 import 'package:anitrack/src/data/anime.dart';
 import 'package:anitrack/src/data/manga.dart';
 import 'package:anitrack/src/data/type.dart';
 import 'package:anitrack/src/service/database.dart';
+import 'package:anitrack/src/ui/bloc/anime_list_bloc.dart';
+import 'package:archive/archive.dart' as archive;
 import 'package:archive/archive_io.dart';
 import 'package:bloc/bloc.dart';
+import 'package:fluttertoast/fluttertoast.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:get_it/get_it.dart';
 import 'package:jikan_api/jikan_api.dart';
+import 'package:path/path.dart' as path;
 import 'package:xml/xml.dart';
 
-part 'settings_state.dart';
-part 'settings_event.dart';
 part 'settings_bloc.freezed.dart';
+part 'settings_event.dart';
+part 'settings_state.dart';
 
 MediumTrackingState malStatusToTrackingState(String status) {
   switch (status) {
@@ -39,6 +45,8 @@ class SettingsBloc extends Bloc<SettingsEvent, SettingsState> {
   SettingsBloc() : super(SettingsState()) {
     on<AnimeListImportedEvent>(_onAnimeListImported);
     on<MangaListImportedEvent>(_onMangaListImported);
+    on<DataExportedEvent>(_onDataExported);
+    on<DataImportedEvent>(_onDataImported);
   }
 
   void _showLoadingSpinner(Emitter<SettingsState> emit) {
@@ -205,4 +213,69 @@ class SettingsBloc extends Bloc<SettingsEvent, SettingsState> {
     // Hide the spinner again
     _hideLoadingSpinner(emit);
   }
+
+  Future<void> _onDataExported(
+    DataExportedEvent event,
+    Emitter<SettingsState> emit,
+  ) async {
+    final al = GetIt.I.get<AnimeListBloc>();
+    final data = {
+      // TODO(Unknown): Track the version here to (maybe) to migrations
+      'animes': al.state.animes.map((anime) => anime.toJson()).toList(),
+      'mangas': al.state.mangas.map((manga) => manga.toJson()).toList(),
+    };
+    final exportData = jsonEncode(data);
+    final date = DateTime.now();
+    final outputPath = path.join(
+      event.path,
+      'anitrack_${date.year}${date.month}${date.day}.json.gz',
+    );
+    archive.GZipEncoder().encode(
+      InputStream(utf8.encode(exportData)),
+      output: OutputFileStream(outputPath),
+    );
+
+    await Fluttertoast.showToast(
+      msg: t.settings.dataExportSuccess,
+    );
+  }
+
+  Future<void> _onDataImported(
+    DataImportedEvent event,
+    Emitter<SettingsState> emit,
+  ) async {
+    final al = GetIt.I.get<AnimeListBloc>();
+    final exportArchive = archive.GZipDecoder().decodeBytes(
+      await File(event.path).readAsBytes(),
+    );
+    final json = jsonDecode(utf8.decode(exportArchive)) as Map<String, dynamic>;
+
+    // Process anime
+    for (final animeRaw
+        in (json['animes']! as List<dynamic>).cast<Map<dynamic, dynamic>>()) {
+      final anime = AnimeTrackingData.fromJson(
+        animeRaw.cast<String, dynamic>(),
+      );
+
+      al.add(
+        AnimeAddedEvent(anime, checkIfExists: true),
+      );
+    }
+
+    // Process manga
+    for (final mangaRaw
+        in (json['mangas']! as List<dynamic>).cast<Map<dynamic, dynamic>>()) {
+      final manga = MangaTrackingData.fromJson(
+        mangaRaw.cast<String, dynamic>(),
+      );
+
+      al.add(
+        MangaAddedEvent(manga, checkIfExists: true),
+      );
+    }
+
+    await Fluttertoast.showToast(
+      msg: t.settings.dataImportSuccess,
+    );
+  }
 }

lib/src/ui/bloc/settings_event.dart

@@ -34,3 +34,19 @@ class MangaListImportedEvent extends SettingsEvent {
   /// The type of list we're importing
   final ImportListType type;
 }
+
+/// Triggered when a data export should be produced.
+class DataExportedEvent extends SettingsEvent {
+  DataExportedEvent(this.path);
+
+  /// The path where the export should be stored.
+  final String path;
+}
+
+/// Triggered when a data export has been picked for import.
+class DataImportedEvent extends SettingsEvent {
+  DataImportedEvent(this.path);
+
+  /// The path of the data export to import.
+  final String path;
+}