/**
 * 存储插件加载器实现
 * 负责动态加载和管理存储插件
 */

import { StoragePlugin, StoragePluginMetadata } from '../interfaces/StoragePlugin';
import { StorageFactory } from './StorageFactory';
import * as fs from 'fs';
import * as path from 'path';

/**
 * 存储插件加载器接口
 */
export interface StoragePluginLoader {
  loadPlugin(plugin: StoragePlugin): void;
  loadPlugins(plugins: StoragePlugin[]): void;
  loadPluginFromPath(pluginPath: string): Promise<void>;
  loadPluginsFromDirectory(directoryPath: string): Promise<void>;
  getLoadedPlugins(): StoragePluginMetadata[];
  unloadPlugin(storageType: string): void;
}

export class StoragePluginLoaderImpl implements StoragePluginLoader {
  // 已加载插件的注册表
  private pluginRegistry: Map<string, StoragePlugin> = new Map();

  /**
   * 加载存储插件
   * @param plugin 存储插件实例
   */
  public loadPlugin(plugin: StoragePlugin): void {
    if (plugin.metadata && plugin.metadata.name) {
      this.pluginRegistry.set(plugin.metadata.name, plugin);
    } else {
      throw new Error('Invalid storage plugin: missing metadata or name');
    }
  }

  /**
   * 批量加载存储插件
   * @param plugins 存储插件实例数组
   */
  public loadPlugins(plugins: StoragePlugin[]): void {
    for (const plugin of plugins) {
      this.loadPlugin(plugin);
    }
  }

  /**
   * 从路径加载存储插件
   * @param pluginPath 插件路径
   */
  public async loadPluginFromPath(pluginPath: string): Promise<void> {
    try {
      // 动态导入插件模块
      const pluginModule = await import(pluginPath);
      const pluginInstance = new pluginModule.default();
      
      // 加载插件
      this.loadPlugin(pluginInstance);
    } catch (error) {
      console.error(`Failed to load storage plugin from ${pluginPath}:`, error);
      throw new Error(`Failed to load storage plugin: ${error instanceof Error ? error.message : String(error)}`);
    }
  }

  /**
   * 从目录加载存储插件
   * @param directoryPath 目录路径
   */
  public async loadPluginsFromDirectory(directoryPath: string): Promise<void> {
    // 实现从目录加载插件的逻辑
    console.log(`Loading plugins from directory: ${directoryPath}`);
  }

  /**
   * 获取已加载的插件元数据
   * @returns 插件元数据数组
   */
  public getLoadedPlugins(): any[] {
    return Array.from(this.pluginRegistry.values()).map(plugin => plugin.metadata);
  }

  /**
   * 卸载存储插件
   * @param storageType 存储类型
   */
  public unloadPlugin(storageType: string): void {
    this.pluginRegistry.delete(storageType);
  }
}

/**
 * 存储插件加载器单例实例
 */
export const storagePluginLoader = new StoragePluginLoaderImpl();