import 'package:sembast/sembast_io.dart';
import 'dart:async';


abstract class SemDbMgrBase<T> {

  final Database database;
  abstract final String repositoryName;

  SemDbMgrBase(this.database);

  // 获取存储
  StoreRef<String, Map<String, dynamic>> get storeRef {
    return StoreRef<String, Map<String, dynamic>>(repositoryName);
  }

  // 转换对象为Map
  Map<String, dynamic> toMap(T item);

  // 从Map创建对象
  T fromMap(Map<String, dynamic> map) {
    // 有些情况下存储的数据并不足以创建实例，此时子类不实现 fromMap 而是新建一个附带更多参数的接口
    // 注意此时 getAll 和 getById 等依赖 fromMap 的函数也不要使用，否则会抛出异常
    throw UnimplementedError('fromMap is not implemented for this repository');
  }

  // 添加或更新记录
  Future<String> addOrUpdate(T item, {String? id}) async {
    final itemMap = toMap(item);
    final recordId = id ?? DateTime.now().millisecondsSinceEpoch.toString();

    await storeRef.record(recordId).put(database, itemMap);
    return recordId;
  }

  // 获取所有记录
  Future<List<T>> getAll() async {
    final records = await storeRef.find(database);
    return records.map((record) => fromMap(record.value)).toList();
  }

  // 根据ID获取记录
  Future<T?> getById(String id) async {
    final record = await storeRef.record(id).get(database);
    return record != null ? fromMap(record) : null;
  }

  // 删除记录
  Future<void> delete(String id) async {
    await storeRef.record(id).delete(database);
  }

  // 清空存储
  Future<void> clear() async {
    await storeRef.delete(database);
  }
}