discord-ws-gateway/dist/index.js

Simple and tiny implementation of Discord's Gateway using web standard APIs

// package.json
var version = "0.1.1";
var homepage = "https://github.com/Chooks22/discord-ws-gateway";

// src/index.ts
var USER_AGENT = `Discord-Gateway/${version} (+${homepage})`;
function createClient(gatewayUrl, identity) {
  return new Client(gatewayUrl, identity);
}
var Client = class {
  static create = createClient;
  #listeners = /* @__PURE__ */ new Map();
  #interval;
  #timeout;
  socket;
  #s = null;
  #zombied = false;
  #url;
  #resume_url;
  #session_id;
  #identity;
  closed = false;
  constructor(gatewayUrl, identity) {
    this.#url = gatewayUrl;
    this.#identity = identity;
    void this.#connect(gatewayUrl);
  }
  #connect(url) {
    this.socket = new WebSocket(`${url}?v=10&encoding=json`);
    this.socket.addEventListener("message", (e) => {
      const data = JSON.parse(e.data);
      switch (data.op) {
        // Dispatch
        case 0: {
          this.#s = data.s;
          const listeners = this.#listeners.get(data.t);
          const listeners_all = this.#listeners.get("ALL");
          if (listeners !== void 0) {
            listeners.forEach((cb) => cb(data));
          }
          if (listeners_all !== void 0) {
            listeners_all.forEach((cb) => cb(data));
          }
          if (data.t === "READY") {
            this.#session_id = data.d.session_id;
            this.#resume_url = data.d.resume_gateway_url;
          }
          break;
        }
        // Hello
        case 10: {
          const interval = data.d.heartbeat_interval;
          const heartbeat = () => this.#heartbeat();
          this.#timeout = setTimeout(() => {
            heartbeat();
            this.#interval = setInterval(heartbeat, interval);
          }, interval * Math.random());
          this.#send({
            op: 2,
            d: {
              ...this.#identity,
              properties: {
                os: this.#identity.properties.os,
                browser: `${this.#identity.properties.browser} ${USER_AGENT}`.trim(),
                device: `${this.#identity.properties.device} ${USER_AGENT}`.trim()
              }
            }
          });
          break;
        }
        // Heartbeat Ack
        case 11: {
          this.#zombied = false;
          break;
        }
        // Heartbeat
        case 1: {
          this.#zombied = false;
          this.#heartbeat();
          break;
        }
        // Reconnect
        case 7: {
          void this.#resume();
          break;
        }
      }
    });
    return new Promise((res) => {
      this.socket.addEventListener("open", res, { once: true });
    });
  }
  #send(data) {
    const payload = JSON.stringify(data);
    this.socket.send(payload);
  }
  #heartbeat() {
    if (this.#zombied) {
      void this.#resume();
      return;
    }
    this.#zombied = true;
    this.#send({ op: 1, d: this.#s });
  }
  async #resume() {
    this.close();
    await this.#connect(this.#resume_url);
    this.#send({
      op: 6,
      d: {
        token: this.#identity.token,
        seq: this.#s,
        session_id: this.#session_id
      }
    });
  }
  /**
   * @todo(Chooks22) handle reconnect cases
   */
  #reconnect() {
    this.close();
    void this.#connect(this.#url);
  }
  addEventListener(event, callback) {
    const listeners = this.#listeners.get(event);
    if (listeners !== void 0) {
      listeners.push(callback);
    } else {
      this.#listeners.set(event, [callback]);
    }
    return this;
  }
  removeEventListener(event, callback) {
    const listeners = this.#listeners.get(event);
    if (listeners !== void 0) {
      if (listeners.length === 1 && listeners[0] === callback) {
        this.#listeners.delete(event);
      } else {
        for (let i = listeners.length; i--; ) {
          if (listeners[i] === callback) {
            listeners.splice(i, 1);
            break;
          }
        }
      }
    }
    return this;
  }
  close(code = 1e3) {
    this.closed = true;
    clearTimeout(this.#timeout);
    clearInterval(this.#interval);
    this.socket.close(code);
  }
};
export {
  Client,
  createClient
};