feat:增加hive模块

lib/models/todo.dart

@@ -1,48 +1,81 @@
 import 'package:flutter/material.dart';
+import 'package:hive/hive.dart';
 
-class TodoItem {
-  num id;
-  String title;
-  String content;
-  bool isCompleted;
-  DateTime? dueDate;
-  TodoPriority priority;
+part 'todo.g.dart';
 
-  TodoItem({
-    required this.id,
+@HiveType(typeId: 0)
+class Todo extends HiveObject {
+  @HiveField(0)
+  late int id;
+
+  @HiveField(1)
+  late String title;
+
+  @HiveField(2)
+  late String content;
+
+  @HiveField(3)
+  late bool isCompleted;
+
+  @HiveField(4)
+  late DateTime? dueDate;
+
+  @HiveField(5)
+  late int priorityIndex;
+
+  @HiveField(6)
+  late DateTime createTime;
+
+  @HiveField(7)
+  late DateTime updateTime;
+
+  TodoPriority get priority => TodoPriority.values[priorityIndex];
+  set priority(TodoPriority value) => priorityIndex = value.index;
+
+  Todo({
+    int? id,
     required this.title,
-    required this.content,
+    this.content = '',
     this.isCompleted = false,
     this.dueDate,
-    this.priority = TodoPriority.medium,
-  });
+    TodoPriority priority = TodoPriority.medium,
+    DateTime? createTime,
+    DateTime? updateTime,
+  }) {
+    // 简单时间戳ID
+    this.id = id ?? DateTime.now().millisecondsSinceEpoch;
+    this.priorityIndex = priority.index;
+    this.createTime = createTime ?? DateTime.now();
+    this.updateTime = updateTime ?? DateTime.now();
+  }
 
-  TodoItem copyWith({
-    num? id,
+  Todo copyWith({
     String? title,
     String? content,
     bool? isCompleted,
     DateTime? dueDate,
     TodoPriority? priority,
   }) {
-    return TodoItem(
-      id: id ?? this.id,
+    return Todo(
+      id: id,
       title: title ?? this.title,
       content: content ?? this.content,
       isCompleted: isCompleted ?? this.isCompleted,
       dueDate: dueDate ?? this.dueDate,
       priority: priority ?? this.priority,
+      createTime: createTime,
+      updateTime: DateTime.now(),
     );
   }
 
-  static TodoItem getEmpty() {
-    return TodoItem(
-        id: 0,
-        title: '',
-        content: '',
-        isCompleted: false,
-        dueDate: null,
-        priority: TodoPriority.medium,
+  static Todo getEmpty() {
+    return Todo(
+      id: 0,
+      title: '',
+      content: '',
+      isCompleted: false,
+      dueDate: null,
+      priority: TodoPriority.medium,
     );
   }
 }