import type { App, ListenProcessParams } from '@kevisual/router';
import { EventEmitter } from 'eventemitter3';
type RemoteAppOptions = {
  app?: App;
  url?: string;
  token?: string;
  username?: string;
  emitter?: EventEmitter;
  id?: string;
  /** 是否启用自动重连，默认 true */
  autoReconnect?: boolean;
  /** 最大重连次数，默认 Infinity */
  maxReconnectAttempts?: number;
  /** 初始重连延迟（毫秒），默认 1000 */
  reconnectDelay?: number;
  /** 重连延迟最大值（毫秒），默认 30000 */
  maxReconnectDelay?: number;
  /** 是否启用指数退避，默认 true */
  enableBackoff?: boolean;
};
/**
 * 远程共享地址类似：https://kevisual.cn/ws/proxy
 */
export class RemoteApp {
  mainApp: App;
  url: string;
  id: string;
  username: string;
  emitter: EventEmitter;
  isConnected: boolean;
  ws: WebSocket;
  remoteIsConnected: boolean;
  isError: boolean = false;
  // 重连相关属性
  autoReconnect: boolean;
  maxReconnectAttempts: number;
  reconnectDelay: number;
  maxReconnectDelay: number;
  enableBackoff: boolean;
  reconnectAttempts: number = 0;
  reconnectTimer: NodeJS.Timeout | null = null;
  isManuallyClosed: boolean = false;
  constructor(opts?: RemoteAppOptions) {
    this.mainApp = opts?.app;
    const token = opts.token;
    const url = opts.url;
    const id = opts.id;
    const username = opts.username;
    this.username = username;
    this.emitter = opts?.emitter || new EventEmitter();
    const _url = new URL(url);
    if (token) {
      _url.searchParams.set('token', token);
    }
    _url.searchParams.set('id', id);
    if (!token && !username) {
      console.error(`[remote-app] 不存在用户名和token ${id}. 权限认证会失败。`);
    }
    this.url = _url.toString();
    this.id = id;
    // 初始化重连相关配置
    this.autoReconnect = opts?.autoReconnect ?? true;
    this.maxReconnectAttempts = opts?.maxReconnectAttempts ?? Infinity;
    this.reconnectDelay = opts?.reconnectDelay ?? 1000;
    this.maxReconnectDelay = opts?.maxReconnectDelay ?? 30000;
    this.enableBackoff = opts?.enableBackoff ?? true;
    this.init();
  }
  async isConnect(): Promise<boolean> {
    const that = this;
    if (this.isConnected) {
      return true;
    }
    // 如果正在进行重连，等待连接成功
    if (this.reconnectTimer !== null) {
      console.log(`远程应用 ${this.id} 正在重连中...`);
    }
    // 等待连接成功（支持初次连接和重连场景）
    return new Promise((resolve) => {
      const timeout = setTimeout(() => {
        resolve(false);
        that.emitter.off('open', listenOnce);
      }, 5000);
      const listenOnce = () => {
        clearTimeout(timeout);
        that.isConnected = true;
        that.remoteIsConnected = true;
        resolve(true);
      };
      that.emitter.once('open', listenOnce);
    });
  }
  getWsURL(url: string) {
    const { protocol } = new URL(url);
    if (protocol.startsWith('ws')) {
      return url.toString()
    }
    const wsProtocol = protocol === 'https:' ? 'wss:' : 'ws:';
    const wsURL = url.toString().replace(protocol, wsProtocol);
    return wsURL;
  }
  async init() {
    if (!this.url) {
      throw new Error('No url provided for remote app');
    }
    if (!this.id) {
      throw new Error('No id provided for remote app');
    }
    this.isError = false;
    // 关闭已有连接
    if (this.ws) {
      this.ws.close();
    }
    const ws = new WebSocket(this.getWsURL(this.url));
    const that = this;
    ws.onopen = function () {
      that.isConnected = true;
      that.onOpen();
      console.log('[remote-app] WebSocket connection opened');
    };
    ws.onclose = function () {
      that.isConnected = false;
      that.onClose();
    }
    ws.onmessage = function (event) {
      that.onMessage(event.data);
    }
    ws.onerror = function (error) {
      that.onError(error);
    }
    this.ws = ws;
  }
  onOpen() {
    this.isError = false;
    this.reconnectAttempts = 0;
    // 清除可能存在的重连定时器
    if (this.reconnectTimer) {
      clearTimeout(this.reconnectTimer);
      this.reconnectTimer = null;
    }
    this.emitter.emit('open', this.id);
  }
  onClose() {
    console.log('远程应用关闭:', this.id);
    this.isConnected = false;
    this.emitter.emit('close', this.id);
    // 触发自动重连逻辑
    if (this.autoReconnect && !this.isManuallyClosed) {
      this.scheduleReconnect();
    }
  }
  /** 计算下一次重连延迟 */
  calculateReconnectDelay(): number {
    if (!this.enableBackoff) {
      return this.reconnectDelay;
    }
    // 指数退避算法：delay = initialDelay * 2^(attempts - 1)
    const delay = this.reconnectDelay * Math.pow(2, this.reconnectAttempts);
    return Math.min(delay, this.maxReconnectDelay);
  }
  /** 安排重连 */
  scheduleReconnect() {
    // 检查是否达到最大重连次数
    if (this.reconnectAttempts >= this.maxReconnectAttempts) {
      console.error(`远程应用 ${this.id} 已达到最大重连次数 ${this.maxReconnectAttempts}，停止重连`);
      this.emitter.emit('maxReconnectAttemptsReached', this.id);
      return;
    }
    // 清除可能存在的定时器
    if (this.reconnectTimer) {
      clearTimeout(this.reconnectTimer);
    }
    const delay = this.calculateReconnectDelay();
    this.reconnectAttempts++;
    console.log(`远程应用 ${this.id} 将在 ${delay}ms 后尝试第 ${this.reconnectAttempts} 次重连`);
    this.reconnectTimer = setTimeout(() => {
      this.reconnectTimer = null;
      try {
        this.init();
      } catch (error) {
        console.error(`远程应用 ${this.id} 重连失败:`, error);
        this.emitter.emit('reconnectFailed', { id: this.id, attempt: this.reconnectAttempts, error });
        // 重连失败后继续尝试重连
        this.scheduleReconnect();
      }
    }, delay);
  }
  /** 手动关闭连接，停止自动重连 */
  disconnect() {
    this.isManuallyClosed = true;
    this.autoReconnect = false;
    // 清除重连定时器
    if (this.reconnectTimer) {
      clearTimeout(this.reconnectTimer);
      this.reconnectTimer = null;
    }
    // 关闭 WebSocket
    if (this.ws) {
      this.ws.close();
    }
  }
  /** 手动重连 */
  reconnect() {
    this.isManuallyClosed = false;
    this.reconnectAttempts = 0;
    // 清除可能存在的定时器
    if (this.reconnectTimer) {
      clearTimeout(this.reconnectTimer);
      this.reconnectTimer = null;
    }
    this.init();
  }
  onMessage(data: any) {
    this.emitter.emit('message', data);
  }
  onError(error: any) {
    console.error(`[remote-app] 远程应用错误: ${this.id}`, error);
    this.isError = true;
    this.emitter.emit('error', error);
  }
  on(event: 'open' | 'close' | 'message' | 'error' | 'maxReconnectAttemptsReached' | 'reconnectFailed', listener: (data: any) => void) {
    this.emitter.on(event, listener);
    return () => {
      this.emitter.off(event, listener);
    };
  }
  json(data: any) {
    this.ws.send(JSON.stringify(data));
  }
  listenProxy() {
    const remoteApp = this;
    const app = this.mainApp;
    const username = this.username;
    const listenFn = async (event: any) => {
      try {
        const data = event.toString();
        const body = JSON.parse(data)
        const bodyData = body?.data as ListenProcessParams;
        const message = bodyData?.message || {};
        const context = bodyData?.context || {};
        if (body?.code === 401) {
          console.error('远程应用认证失败，请检查 token 是否正确');
          this.isError = true;
          return;
        }
        if (body?.type !== 'proxy') return;
        if (!body.id) {
          remoteApp.json({
            id: body.id,
            data: {
              code: 400,
              message: 'id is required',
            },
          });
          return;

        }
        const res = await app.run(message, context);
        remoteApp.json({
          id: body.id,
          data: {
            code: res.code,
            data: res.data,
            message: res.message,
          },
        });
      } catch (error) {
        console.error('处理远程代理请求出错:', error);
      }
    };
    remoteApp.json({
      id: this.id,
      type: 'registryClient',
      username: username,
    });
    console.log(`远程应用 ${this.id} (${username}) 已注册到主应用，等待消息...`);
    remoteApp.emitter.on('message', listenFn);
    const closeMessage = () => {
      remoteApp.emitter.off('message', listenFn);
    }
    remoteApp.emitter.once('close', () => {
      closeMessage();
    });
    return () => {
      closeMessage();
    };
  }
}