add sqllite utils

lib/config/database_helper.dart

@@ -0,0 +1,56 @@
+import 'dart:io';
+import 'package:sqflite/sqflite.dart';
+import 'package:path/path.dart';
+import 'package:path_provider/path_provider.dart';
+
+class DatabaseHelper {
+  static final DatabaseHelper _instance = DatabaseHelper._internal();
+  factory DatabaseHelper() => _instance;
+  static Database? _database;
+
+  DatabaseHelper._internal();
+
+  Future<Database> get database async {
+    if (_database != null) return _database!;
+    _database = await _initDatabase();
+    return _database!;
+  }
+
+  Future<Database> _initDatabase() async {
+    Directory documentsDirectory = await getApplicationDocumentsDirectory();
+    String path = join(documentsDirectory.path, 'chat.db');
+    return await openDatabase(
+      path,
+      version: 1,
+      onCreate: _onCreate,
+    );
+  }
+
+  Future<void> _onCreate(Database db, int version) async {
+    await db.execute('''
+      CREATE TABLE messages (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        role TEXT NOT NULL,
+        message TEXT NOT NULL,
+        timestamp INTEGER DEFAULT (strftime('%s', 'now'))
+      ''');
+  }
+
+  // 插入一条消息
+  Future<int> insertMessage(Map<String, dynamic> message) async {
+    Database db = await database;
+    return await db.insert('messages', message);
+  }
+
+  // 获取所有消息（按时间排序）
+  Future<List<Map<String, dynamic>>> getMessages() async {
+    Database db = await database;
+    return await db.query('messages', orderBy: 'timestamp ASC');
+  }
+
+  // 删除所有消息
+  Future<int> clearMessages() async {
+    Database db = await database;
+    return await db.delete('messages');
+  }
+}

lib/models/message_model.dart

@@ -0,0 +1,13 @@
+class Message {
+  final String role;  // 'user' 或 'assistant'
+  final String message;
+
+  Message({required this.role, required this.message});
+
+  Map<String, dynamic> toMap() {
+    return {
+      'role': role,
+      'message': message,
+    };
+  }
+}

lib/screens/chat_screen.dart

@@ -4,7 +4,9 @@ import '../widgets/chat_bubble.dart';
 import '../widgets/chat_input.dart';
 import '../widgets/gradient_background.dart';
 import '../models/chat_message.dart';
-import 'dart:convert';
+//import 'dart:convert';
+import '../config/database_helper.dart';
+import '../models/message_model.dart';
 
 class ChatScreen extends StatefulWidget {
   const ChatScreen({super.key});
@@ -18,6 +20,9 @@ class _ChatScreenState extends State<ChatScreen> {
   int? _currentStreamingMessageIndex;
   int _lastUserMessageCount = 0; // 添加这个变量跟踪用户消息数量
 
+  final DatabaseHelper _dbHelper = DatabaseHelper();
+  List<Message> _messagesDB = [];
+
   void _handleSendMessage(String text) {
     if (text.trim().isEmpty) return;
     setState(() {
@@ -41,6 +46,12 @@ class _ChatScreenState extends State<ChatScreen> {
       ));
       _lastUserMessageCount = _getUserMessageCount(); // 更新用户消息计数
       _currentStreamingMessageIndex = null; // 重置流索引，强制创建新气泡
+
+      _addMessage(Message(
+        role: 'user',
+        message: text,
+      ));
+
     });
   }
 
@@ -76,6 +87,11 @@ class _ChatScreenState extends State<ChatScreen> {
         }
       }
 
+      _addMessage(Message(
+        role: 'assistant',
+        message: text,
+      ));
+
       // 如果完成了，重置索引
       if (isComplete) {
         _currentStreamingMessageIndex = null;
@@ -83,6 +99,20 @@ class _ChatScreenState extends State<ChatScreen> {
     });
   }
 
+  Future<void> _loadMessages() async {
+    List<Map<String, dynamic>> records = await _dbHelper.getMessages();
+    setState(() {
+      _messagesDB = records.map((record) => Message(
+        role: record['role'],
+        message: record['message'],
+      )).toList();
+    });
+  }
+
+  Future<void> _addMessage(Message message) async {
+    await _dbHelper.insertMessage(message.toMap());
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

pubspec.yaml

@@ -38,6 +38,8 @@ dependencies:
   record: ^6.0.0
   http: ^1.2.1
   path_provider: ^2.1.2
+  sqflite: ^2.4.2
+  path: ^1.9.1
 
 dev_dependencies:
   flutter_test: