function postReply(id, type, payload) {
  self.postMessage({ id, type, ok: true, ...payload });
}

function postError(id, type, error) {
  self.postMessage({
    id,
    type,
    ok: false,
    error: error?.message ?? String(error),
  });
}

function pythonRuntimeAvailable() {
  return typeof self.loadPyodide === "function" || Boolean(self.pyodide?.runPythonAsync);
}

self.addEventListener("message", async (event) => {
  const message = event.data ?? {};
  const { id, type } = message;
  try {
    if (type === "start") {
      const ready = pythonRuntimeAvailable();
      postReply(id, type, {
        runtimeMode: "browser-python-wasm-worker",
        runtimeExecutionReady: ready,
        status: ready
          ? "browser_python_wasm_runtime_ready"
          : "blocked_browser_python_wasm_runtime_missing",
        executionEnabled: false,
        promotionAllowed: false,
      });
      return;
    }
    throw new Error("blocked_browser_python_wasm_runtime_missing");
  } catch (error) {
    postError(id, type, error);
  }
});