browser-webapp/src/messages.ts

import exchangeCommunicationKeys from "./messages/exchangeCommunicationKeys.js";
import {
  deleteQuery,
  getAuthStatus,
  getAuthStatusKnown,
  getLoggedInDefer,
  getQueries,
  getQuery,
  resetLoggedInDefer,
  setAuthStatus,
  setAuthStatusKnown,
  getAuthStatusDefer,
} from "./vars.js";
const kernelMessageHandlers = {
  exchangeCommunicationKeys,
};

export async function handleIncomingMessage(event: MessageEvent) {
  if (event.source === null) {
    return;
  }
  if (event.source === window) {
    return;
  }

  const data = event.data?.data;
  if (event.data.method === "log") {
    if (data?.isErr === false) {
      console.log(data.message);
      return;
    }
    console.error(data.message);
  }

  if (event.data.method === "kernelAuthStatus") {
    setAuthStatus(data);
    if (!getAuthStatusKnown()) {
      getAuthStatusDefer().resolve();
      setAuthStatusKnown(true);
      console.log("bootloader is now initialized");
      if (!getAuthStatus().loginComplete) {
        console.log("user is not logged in: waiting until login is confirmed");
      } else {
        getLoggedInDefer().resolve();
      }
      if (getAuthStatus().logoutComplete) {
        resetLoggedInDefer();
        setAuthStatusKnown(false);
      }
    }
    return;
  }

  if (!("nonce" in event.data)) {
    (event.source as WindowProxy).postMessage(
      {
        nonce: "N/A",
        method: "response",
        err: "message sent to kernel with no nonce",
      },
      event.origin,
    );
    return;
  }

  if (!("method" in event.data)) {
    (event.source as WindowProxy).postMessage(
      {
        nonce: event.data.nonce,
        method: "response",
        err: "message sent to kernel with no method",
      },
      event.origin,
    );
    return;
  }

  if (event.data.method in kernelMessageHandlers) {
    let response;

    try {
      response = await kernelMessageHandlers[event.data.method](
        event.data.data,
      );
    } catch (e: any) {
      response = { err: (e as Error).message };
    }

    (event.source as WindowProxy).postMessage(
      {
        nonce: event.data.nonce,
        data: response,
      },
      event.origin,
    );
    return;
  }
  if (!(event.data.nonce in getQueries())) {
    return;
  }

  let receiveResult = getQuery(event.data.nonce);
  if (event.data.method === "response") {
    deleteQuery(event.data.nonce);
  }

  receiveResult?.(event.data);

  if (["moduleCall", "response"].includes(event.data.method)) {
    return;
  }

  (event.source as WindowProxy).postMessage(
    {
      nonce: event.data.nonce,
      method: "response",
      err:
        "unrecognized method (user may need to log in): " + event.data.method,
    },
    event.origin,
  );
  return;
}