import { useCallback, useEffect, useRef } from "react";
import type { RequestAdmission } from "../services/HttpService";

export const NO_LONGER_PERMITTED = "You can no longer do this here, so it was not sent.";

/**
 * An `admit` for one write (see `HttpService`'s `FetchOptions.admit`). It reads the latest answer each time it is
 * asked before dispatch, so a permission withdrawn during token/proof waits stops the write. An acknowledged
 * answer keeps its outcome; operation ownership is checked separately before publication.
 */
export const useAdmission = (permitted: boolean) => {
    const latest = useRef(permitted);
    useEffect(() => {
        latest.current = permitted;
    }, [permitted]);
    return useCallback<RequestAdmission>((phase) => {
        if (phase !== 'answer' && !latest.current) throw new Error(NO_LONGER_PERMITTED);
    }, []);
};