feature: Save logging to cache directory

lib/main.dart

@@ -50,8 +50,8 @@ Future<Map<String, dynamic>> loadConfig() async {
 }
 
 void main() async {
-  final crashProvider = CrashLogNotifier();
   WidgetsFlutterBinding.ensureInitialized();
+  final crashProvider = CrashLogNotifier();
 
   if (kIsWeb) {
     html.document.onContextMenu.listen((event) => event.preventDefault());

lib/models/error_log_model.dart

@@ -0,0 +1,90 @@
+import 'package:flutter/material.dart';
+
+import 'package:collection/collection.dart';
+import 'package:logging/logging.dart';
+
+enum ErrorType {
+  severe,
+  warning,
+  shout,
+}
+
+class ErrorLogModel {
+  final ErrorType type;
+  final String message;
+  final DateTime time;
+  final StackTrace? stackTrace;
+
+  const ErrorLogModel({
+    required this.type,
+    required this.message,
+    required this.time,
+    required this.stackTrace,
+  });
+
+  factory ErrorLogModel.fromLogRecord(LogRecord record) {
+    late ErrorType type;
+    if (record.level == Level.WARNING) {
+      type = ErrorType.warning;
+    } else if (record.level == Level.SHOUT) {
+      type = ErrorType.shout;
+    } else {
+      type = ErrorType.severe;
+    }
+
+    return ErrorLogModel(
+      type: type,
+      message: record.message,
+      time: record.time,
+      stackTrace: record.stackTrace,
+    );
+  }
+
+  String get label {
+    var join = _label;
+    if (join.length > 250) {
+      return "${join.substring(0, 250)}... \n \nTruncated copy log to see more";
+    } else {
+      return join;
+    }
+  }
+
+  String get _label {
+    return [
+      type.name.toUpperCase(),
+      "  |  ",
+      message,
+    ].join();
+  }
+
+  String get content => [
+        time.toIso8601String(),
+        "\n",
+        "\n",
+        stackTrace,
+      ].whereNotNull().join();
+
+  String get clipBoard => [_label, content].toString();
+
+  Color get color => switch (type) {
+        ErrorType.severe => Colors.redAccent,
+        ErrorType.warning => Colors.orange,
+        ErrorType.shout => Colors.yellowAccent,
+      };
+
+  Map<String, dynamic> toJson() => {
+        'time': time.toIso8601String(),
+        'level': type.name,
+        'message': message,
+        'stackTrace': stackTrace?.toString(),
+      };
+
+  static ErrorLogModel fromJson(Map<String, dynamic> json) {
+    return ErrorLogModel(
+      type: ErrorType.values.firstWhereOrNull((level) => level.name == json['level']) ?? ErrorType.warning,
+      message: json['message'],
+      stackTrace: json['stackTrace'] != null ? StackTrace.fromString(json['stackTrace']) : null,
+      time: DateTime.parse(json['time']),
+    );
+  }
+}

lib/providers/crash_log_provider.dart

@@ -1,75 +1,32 @@
+import 'dart:convert';
+import 'dart:io';
+
 import 'package:flutter/foundation.dart';
-import 'package:flutter/material.dart';
 
-import 'package:collection/collection.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:logging/logging.dart';
+import 'package:path_provider/path_provider.dart';
 
-enum ErrorType {
-  severe,
-  warning,
-  shout,
-}
-
-class ErrorViewModel {
-  final LogRecord rec;
-
-  const ErrorViewModel({required this.rec});
-
-  ErrorType get type {
-    if (rec.level == Level.WARNING) {
-      return ErrorType.warning;
-    }
-    if (rec.level == Level.SHOUT) {
-      return ErrorType.shout;
-    }
-    return ErrorType.severe;
-  }
-
-  String get label {
-    var join = [
-      type.name.toUpperCase(),
-      "  |  ",
-      rec.message,
-    ].join();
-    if (join.length > 250) {
-      return "${join.substring(0, 80)}... \n \nTruncated copy log to see more";
-    } else {
-      return join;
-    }
-  }
-
-  String get content => [
-        rec.time.toIso8601String(),
-        "\n",
-        "\n",
-        rec.stackTrace,
-      ].whereNotNull().join();
-
-  String get clipBoard => [label, content].toString();
-
-  Color get color => switch (type) {
-        ErrorType.severe => Colors.redAccent,
-        ErrorType.warning => Colors.orange,
-        ErrorType.shout => Colors.yellowAccent,
-      };
-}
+import 'package:fladder/models/error_log_model.dart';
 
-final crashLogProvider = StateNotifierProvider<CrashLogNotifier, List<ErrorViewModel>>((ref) => CrashLogNotifier());
+final crashLogProvider = StateNotifierProvider<CrashLogNotifier, List<ErrorLogModel>>((ref) => CrashLogNotifier());
 
-class CrashLogNotifier extends StateNotifier<List<ErrorViewModel>> {
+class CrashLogNotifier extends StateNotifier<List<ErrorLogModel>> {
   CrashLogNotifier() : super([]) {
     init();
   }
 
   late final Logger logger;
-  final maxLength = 100;
+  final maxLength = 50;
+  String? logFilePath;
 
-  void init() {
+  void init() async {
     logger = Logger.root;
     logger.level = Level.ALL;
     logger.onRecord.listen(logPrint);
+
     FlutterError.onError = (FlutterErrorDetails details) => logFile(details);
+
     PlatformDispatcher.instance.onError = (error, stack) {
       logFile(FlutterErrorDetails(
         exception: error,
@@ -78,27 +35,59 @@ class CrashLogNotifier extends StateNotifier<List<ErrorViewModel>> {
       ));
       return false;
     };
+
+    if (!kIsWeb) {
+      await _initializeLogFile();
+      await _loadLogsFromFile();
+    }
+  }
+
+  Future<void> _initializeLogFile() async {
+    final directory = await getApplicationCacheDirectory();
+    logFilePath = '${directory.path}/crash_logs.json';
+  }
+
+  Future<void> _loadLogsFromFile() async {
+    if (logFilePath == null) return;
+    final file = File(logFilePath!);
+    if (await file.exists()) {
+      final content = await file.readAsString();
+      final List<dynamic> jsonData = jsonDecode(content);
+      state = jsonData.map((json) => ErrorLogModel.fromJson(json)).toList();
+    }
+  }
+
+  Future<void> _saveLogsToFile() async {
+    if (logFilePath == null) return;
+    final file = File(logFilePath!);
+    final jsonData = state.map((log) => log.toJson()).toList();
+    await file.writeAsString(jsonEncode(jsonData));
   }
 
   void clearLogs() {
     state = [];
+    if (!kIsWeb) {
+      _saveLogsToFile();
+    }
   }
 
   void logPrint(LogRecord rec) {
     if (kDebugMode) {
       print('${rec.level.name}: ${rec.time}: ${rec.message}');
     }
     if (rec.level > Level.INFO) {
-      state = [ErrorViewModel(rec: rec), ...state];
+      state = [ErrorLogModel.fromLogRecord(rec), ...state];
       if (state.length >= maxLength) {
         state = state.sublist(0, maxLength);
       }
+      if (!kIsWeb) {
+        _saveLogsToFile();
+      }
     }
   }
 
   void logFile(FlutterErrorDetails details) {
     logger.severe('Flutter error: ${details.exception}', details.exception, details.stack);
-
     if (details.stack != null && kDebugMode) {
       print('${details.stack}');
     }

lib/screens/crash_screen/crash_screen.dart

@@ -4,6 +4,7 @@ import 'package:flutter/services.dart';
 
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import 'package:fladder/models/error_log_model.dart';
 import 'package:fladder/providers/crash_log_provider.dart';
 import 'package:fladder/screens/shared/fladder_snackbar.dart';
 import 'package:fladder/util/list_padding.dart';

lib/screens/shared/detail_scaffold.dart

@@ -161,9 +161,10 @@ class _DetailScaffoldState extends ConsumerState<DetailScaffold> {
                   ),
                   Padding(
                     padding: EdgeInsets.only(
-                        bottom: 0,
-                        left: MediaQuery.of(context).padding.left,
-                        top: MediaQuery.of(context).padding.top + 50),
+                      bottom: 0,
+                      left: MediaQuery.of(context).padding.left,
+                      top: MediaQuery.of(context).padding.top,
+                    ),
                     child: ConstrainedBox(
                       constraints: BoxConstraints(
                         minHeight: MediaQuery.sizeOf(context).height,