import WebSocket from "ws";
import Logs from "./logs.js";

/**
 * 解析推送过来的消息
 * @param {*} data
 * @returns {object}
 */
const parseMessage = (data) => {
  let message;
  try {
    message = JSON.parse(data);
  }
  catch(e) {
    message = { text: data.toString() };
  }
  return message;
}

/**
 * 自定义Websocket类
 * 添加自动发送ping指令
 */
class WsClient {
  #websocket;
  #pingTimer;
  constructor(wsserver, options) {
    this.#websocket = new WebSocket(wsserver, options);
  }
  get readyState() {
    return this.#websocket.readyState;
  }
  on(type, callback) {
    switch(type) {
      case 'open':
        this.#websocket.on('open', event => {
          this.#pingTimer = setInterval(() => {
            if (this.readyState === WebSocket.OPEN) {
              this.#websocket.send('PING');
            }
          }, 10_000);
          callback(event);
        });
        break;
      case 'message':
        this.#websocket.on('message', message => {
          const data = parseMessage(message);
          callback(data);
        });
        break;
      case 'error':
        this.#websocket.on('error', error => {
          clearInterval(this.#pingTimer);
          callback(error);
        });
        break;
      case 'close':
        this.#websocket.on('close', code => {
          clearInterval(this.#pingTimer);
          callback(code);
        });
        break;
      default:
        console.log(type, callback);
    }
    return this;
  }
  send(message) {
    this.#websocket.send(JSON.stringify(message));
  }
  close(code) {
    this.#websocket.close(code);
  }
}

/**
 * 建立长连接
 */
class WebSocketClient {
  #url;
  #wsClient = null;
  #connecting = 0;
  #retryTimer = null;
  #retryCount = 0;
  #options = {};
  #callback = {};

  constructor(url, options) {
    this.#url = url;
    this.#options = options;
  }

  get wsClient() {
    return this.#wsClient;
  }

  get connecting() {
    return this.#connecting;
  }

  #setCallback(type, callback) {
    if (['open', 'message', 'error', 'close'].includes(type)) {
      this.#callback[type] = callback;
    }
    else {
      throw new Error(`Invalid callback type: ${type}`);
    }
  }

  #runCallback(type, event) {
    if (this.#callback[type]) {
      this.#callback[type](event);
    }
  }

  /**
   * 建立连接（若已在连接中/已连接，会先关闭旧连接再重建）
   * @returns {WsClient}
   */
  connect() {
    if (this.#retryTimer) {
      clearTimeout(this.#retryTimer);
      this.#retryTimer = null;
    }

    // const { url, onmessage } = this.#connectInfo;
    const wsClient = new WsClient(this.#url, this.#options);
    this.#wsClient = wsClient;
    this.#connecting = 1;

    wsClient.on('open', event => {
      this.#retryCount = 0;
      this.#connecting = 0;
      if (this.#retryTimer) {
        clearTimeout(this.#retryTimer);
        this.#retryTimer = null;
      }
      this.#runCallback('open', event);
      // Logs.outDev('connect success');
    });

    wsClient.on('message', data => {
      const message = data;
      if (message.toUpperCase?.() == 'PONG' || message?.text?.toUpperCase?.() == 'PONG') {
        return;
      }
      this.#runCallback('message', data);
      // Logs.outDev('receive message', message);
    });

    wsClient.on('error', event => {
      Logs.outDev('connect error', event);
      this.#runCallback('error', event);
    });

    wsClient.on('close', event => {
      this.#runCallback('close', event);
      if (event.code == 1000) { // 手动断开，直接结束
        this.#wsClient = null;
        this.#connecting = 0;
        if (this.#retryTimer) {
          clearTimeout(this.#retryTimer);
          this.#retryTimer = null;
        }
        Logs.outDev('close connection autonomously');
        return;
      }

      // 异常断开，重新尝试连接
      this.#retryCount += 1;
      if (this.#retryCount > 180) {
        this.#wsClient = null;
        this.#connecting = 0;
        Logs.outDev('ws connect retry reached maximum limit');
        return;
      }

      let timeout = 5;
      if (this.#retryCount > 24) {
        timeout = 30;
      }
      else if (this.#retryCount > 40) {
        timeout = 60;
      }

      this.#connecting = 1;
      this.#retryTimer = setTimeout(() => {
        this.connect();
      }, 1000 * timeout);
      Logs.outDev('connect closed, try again after %d seconds', timeout);
    });

    return wsClient;
  }

  /**
   * 手动关闭连接（默认 code=1000）
   */
  close(code = 1000) {
    if (this.#retryTimer) {
      clearTimeout(this.#retryTimer);
      this.#retryTimer = null;
    }
    this.#retryCount = 0;
    this.#connecting = 0;
    this.#wsClient?.close(code);
  }

  /**
   * 发送消息
   * @param {*} message
   */
  send(message) {
    this.#wsClient?.send(message);
  }

  /**
   * 绑定事件
   * @param {*} type
   * @param {*} callback
   * @returns
   */
  on(type, callback) {
    this.#setCallback(type, callback);
    return this;
  }
}

export default WebSocketClient;