client.js

// BunTop client library - injected into the webview on load.
(() => {
  const pending = new Map();
  let nextId = 1;
  let ws;
  let reconnectDelay = 500;

  function connect() {
    ws = new WebSocket(`ws://127.0.0.1:__BUNTOP_PORT__/__buntop_ws`);

    ws.addEventListener("open", () => {
      reconnectDelay = 500;
    });

    ws.addEventListener("message", (event) => {
      const msg = JSON.parse(event.data);

      if (msg.type === "response") {
        const entry = pending.get(msg.id);
        if (!entry) return;
        pending.delete(msg.id);
        if (msg.error) entry.reject(new Error(msg.error));
        else entry.resolve(msg.result);
        return;
      }

      if (msg.type === "event") {
        window.dispatchEvent(new CustomEvent(`buntop:${msg.event}`, { detail: msg.data }));
        if (msg.event === "second-instance") window.focus();
      }
    });

    ws.addEventListener("close", () => {
      for (const { reject } of pending.values()) reject(new Error("Connection closed"));
      pending.clear();
      setTimeout(connect, reconnectDelay);
      reconnectDelay = Math.min(reconnectDelay * 2, 5000);
    });
  }
  connect();

  function ready() {
    return new Promise((resolve) => {
      if (ws.readyState === WebSocket.OPEN) resolve();
      else ws.addEventListener("open", () => resolve(), { once: true });
    });
  }

  async function call(name, ...args) {
    await ready();
    const id = nextId++;
    return new Promise((resolve, reject) => {
      pending.set(id, { resolve, reject });
      ws.send(JSON.stringify({ type: "call", id, name, args }));
    });
  }

  function getSize() {
    return { width: window.outerWidth, height: window.outerHeight };
  }

  function getInnerSize() {
    return { width: window.innerWidth, height: window.innerHeight };
  }

  function getPosition() {
    return { x: window.screenX, y: window.screenY };
  }

  window.buntop = {
    info: __BUNTOP_INFO__,
    call,
    ready,
    getSize,
    getInnerSize,
    getPosition,
    close: () => window.close(),
  };
})();