implemented chat archive

app/lib/features/chat_archive/domain/entities/chat_entity.dart

@@ -0,0 +1,23 @@
+class ChatEntity {
+  static final _namePattern = RegExp(r"^(.*?) - (.*?)\.md$");
+
+  final String fileName;
+
+  final String? name;
+  final DateTime? dateTime;
+
+  ChatEntity._(this.fileName, {this.name, this.dateTime});
+
+  factory ChatEntity.fromFileName(String fileName) {
+    final match = _namePattern.firstMatch(fileName);
+
+    return ChatEntity._(
+      fileName,
+      name: match?.group(1),
+      dateTime: (match != null) ? DateTime.tryParse(match.group(2)!) : null,
+    );
+  }
+
+  @override
+  String toString() => name ?? fileName;
+}

app/lib/features/chat_archive/domain/repositories/chat_archive.dart

@@ -0,0 +1,72 @@
+import 'package:bang_navigator/features/chat_archive/data/repositories/chat_archive_file.dart';
+import 'package:bang_navigator/features/chat_archive/domain/entities/chat_entity.dart';
+import 'package:bang_navigator/features/kagi/data/services/chat.dart';
+import 'package:exceptions/exceptions.dart';
+import 'package:path/path.dart' as path;
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:rxdart/rxdart.dart';
+
+part 'chat_archive.g.dart';
+
+@Riverpod()
+class ChatArchiveRepository extends _$ChatArchiveRepository {
+  Future<List<ChatEntity>> _listArchivedChats() async {
+    final files =
+        await ref.read(chatArchiveFileRepositoryProvider.notifier).list();
+
+    return files
+        .where((file) => path.extension(file.path) == '.md')
+        .map((file) => ChatEntity.fromFileName(path.basename(file.path)))
+        .toList();
+  }
+
+  Future<Result<void>> archiveChat(String fileName, Uri url) async {
+    final contentsResult =
+        await ref.read(kagiChatServiceProvider.notifier).downloadChat(url);
+
+    return contentsResult.flatMapAsync(
+      (contents) => ref
+          .read(chatArchiveFileRepositoryProvider.notifier)
+          .write(fileName, contents),
+    );
+  }
+
+  Future<Result<String>> readChat(String fileName) async {
+    final contentsResult = await Result.fromAsync(
+      () => ref.read(chatArchiveFileRepositoryProvider.notifier).read(fileName),
+    );
+
+    return contentsResult.fold(
+      (value) => (value == null)
+          ? Result.failure(
+              ErrorMessage(
+                source: 'Chat Archive',
+                message: 'Chat $fileName not found',
+              ),
+            )
+          : Result.success(value),
+      onFailure: Result.failure,
+    );
+  }
+
+  @override
+  Stream<List<ChatEntity>> build() async* {
+    final fileRepository = ref.watch(chatArchiveFileRepositoryProvider);
+
+    yield* ConcatStream([
+      _listArchivedChats().asStream(),
+      fileRepository.asyncMap(
+        (_) => _listArchivedChats(),
+      ),
+    ]);
+  }
+}
+
+@Riverpod()
+Future<String> readArchivedChat(
+    ReadArchivedChatRef ref, String fileName) async {
+  final result =
+      await ref.read(chatArchiveRepositoryProvider.notifier).readChat(fileName);
+
+  return result.value;
+}

app/lib/features/chat_archive/domain/repositories/chat_archive.g.dart

@@ -0,0 +1,176 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'chat_archive.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+String _$readArchivedChatHash() => r'e7d646a0ea22fe24d96e97f86c1d46fe83818508';
+
+/// Copied from Dart SDK
+class _SystemHash {
+  _SystemHash._();
+
+  static int combine(int hash, int value) {
+    // ignore: parameter_assignments
+    hash = 0x1fffffff & (hash + value);
+    // ignore: parameter_assignments
+    hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+    return hash ^ (hash >> 6);
+  }
+
+  static int finish(int hash) {
+    // ignore: parameter_assignments
+    hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
+    // ignore: parameter_assignments
+    hash = hash ^ (hash >> 11);
+    return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+  }
+}
+
+/// See also [readArchivedChat].
+@ProviderFor(readArchivedChat)
+const readArchivedChatProvider = ReadArchivedChatFamily();
+
+/// See also [readArchivedChat].
+class ReadArchivedChatFamily extends Family<AsyncValue<String>> {
+  /// See also [readArchivedChat].
+  const ReadArchivedChatFamily();
+
+  /// See also [readArchivedChat].
+  ReadArchivedChatProvider call(
+    String fileName,
+  ) {
+    return ReadArchivedChatProvider(
+      fileName,
+    );
+  }
+
+  @override
+  ReadArchivedChatProvider getProviderOverride(
+    covariant ReadArchivedChatProvider provider,
+  ) {
+    return call(
+      provider.fileName,
+    );
+  }
+
+  static const Iterable<ProviderOrFamily>? _dependencies = null;
+
+  @override
+  Iterable<ProviderOrFamily>? get dependencies => _dependencies;
+
+  static const Iterable<ProviderOrFamily>? _allTransitiveDependencies = null;
+
+  @override
+  Iterable<ProviderOrFamily>? get allTransitiveDependencies =>
+      _allTransitiveDependencies;
+
+  @override
+  String? get name => r'readArchivedChatProvider';
+}
+
+/// See also [readArchivedChat].
+class ReadArchivedChatProvider extends AutoDisposeFutureProvider<String> {
+  /// See also [readArchivedChat].
+  ReadArchivedChatProvider(
+    String fileName,
+  ) : this._internal(
+          (ref) => readArchivedChat(
+            ref as ReadArchivedChatRef,
+            fileName,
+          ),
+          from: readArchivedChatProvider,
+          name: r'readArchivedChatProvider',
+          debugGetCreateSourceHash:
+              const bool.fromEnvironment('dart.vm.product')
+                  ? null
+                  : _$readArchivedChatHash,
+          dependencies: ReadArchivedChatFamily._dependencies,
+          allTransitiveDependencies:
+              ReadArchivedChatFamily._allTransitiveDependencies,
+          fileName: fileName,
+        );
+
+  ReadArchivedChatProvider._internal(
+    super._createNotifier, {
+    required super.name,
+    required super.dependencies,
+    required super.allTransitiveDependencies,
+    required super.debugGetCreateSourceHash,
+    required super.from,
+    required this.fileName,
+  }) : super.internal();
+
+  final String fileName;
+
+  @override
+  Override overrideWith(
+    FutureOr<String> Function(ReadArchivedChatRef provider) create,
+  ) {
+    return ProviderOverride(
+      origin: this,
+      override: ReadArchivedChatProvider._internal(
+        (ref) => create(ref as ReadArchivedChatRef),
+        from: from,
+        name: null,
+        dependencies: null,
+        allTransitiveDependencies: null,
+        debugGetCreateSourceHash: null,
+        fileName: fileName,
+      ),
+    );
+  }
+
+  @override
+  AutoDisposeFutureProviderElement<String> createElement() {
+    return _ReadArchivedChatProviderElement(this);
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return other is ReadArchivedChatProvider && other.fileName == fileName;
+  }
+
+  @override
+  int get hashCode {
+    var hash = _SystemHash.combine(0, runtimeType.hashCode);
+    hash = _SystemHash.combine(hash, fileName.hashCode);
+
+    return _SystemHash.finish(hash);
+  }
+}
+
+mixin ReadArchivedChatRef on AutoDisposeFutureProviderRef<String> {
+  /// The parameter `fileName` of this provider.
+  String get fileName;
+}
+
+class _ReadArchivedChatProviderElement
+    extends AutoDisposeFutureProviderElement<String> with ReadArchivedChatRef {
+  _ReadArchivedChatProviderElement(super.provider);
+
+  @override
+  String get fileName => (origin as ReadArchivedChatProvider).fileName;
+}
+
+String _$chatArchiveRepositoryHash() =>
+    r'c53b0d2704953a205c12357642237e15e8ffd3b1';
+
+/// See also [ChatArchiveRepository].
+@ProviderFor(ChatArchiveRepository)
+final chatArchiveRepositoryProvider = AutoDisposeStreamNotifierProvider<
+    ChatArchiveRepository, List<ChatEntity>>.internal(
+  ChatArchiveRepository.new,
+  name: r'chatArchiveRepositoryProvider',
+  debugGetCreateSourceHash: const bool.fromEnvironment('dart.vm.product')
+      ? null
+      : _$chatArchiveRepositoryHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef _$ChatArchiveRepository = AutoDisposeStreamNotifier<List<ChatEntity>>;
+// ignore_for_file: type=lint
+// ignore_for_file: subtype_of_sealed_class, invalid_use_of_internal_member, invalid_use_of_visible_for_testing_member