new/frontends/react/src/usePyodideBackend.ts

import { useCallback, useEffect, useRef, useState } from "react";
import * as Comlink from "comlink";

import type { PyodideBackend } from "./PyodideBackend.ts";

export default function usePyodideBackend() {
  const backendRef = useRef<Comlink.Remote<PyodideBackend> | null>(null);
  const workerRef = useRef<Worker | null>(null);
  const [isReady, setIsReady] = useState<boolean>(false);

  useEffect(() => {
    const worker = new Worker(
      new URL("./pyodide.worker.ts", import.meta.url),
      { type: "module" }
    );

    const backend = Comlink.wrap<PyodideBackend>(worker);

    backendRef.current = backend;
    workerRef.current = worker;

    (async () => {
      try {
        await backend.init();
        console.log("Pyodide intialized")
        setIsReady(true);
      } catch (error) {
        console.error("Failed to initialize Pyodide backend:", error);
      }
    })();

    return () => {
      if (backendRef.current) {
        backendRef.current[Comlink.releaseProxy]();
        backendRef.current = null;
      }

      workerRef.current?.terminate();
      workerRef.current = null;

      setIsReady(false);
    };
  }, []);

  const getBackend = useCallback((): Comlink.Remote<PyodideBackend> => {
    if (!backendRef.current) {
      throw new Error("Pyodide backend is not ready");
    }
    return backendRef.current;
  }, []);

  return { getBackend, backendReady: isReady };
}