import { useEffect, useRef } from 'react';
import type { ConsentInstrumentId } from '../config/consentInstruments';
import { useOptionalWebSocketServiceContext } from '../services/WebSocketService';
import { AUTHORIZATION_ANSWER_EVENT, isRecordAnswerFor, onRecordAuthorizationAnswer, type AuthorizationAnswerNotice } from '../utils/recordAuthorizationAnswers';
import { useRereadOnReturn } from './useRereadOnReturn';

/**
 * Tells one agreement row that its answer may have changed: an answer returned in this client, or the server's notice
 * of one accepted elsewhere for this patient, this document and the session's practice. The notice never carries the
 * answer, so it only invalidates; the row confirms by reading its own status. Coming back to the window reads quietly,
 * unless the row's surface already rereads it when the page is seen again (no `onReturn`).
 */
export const useAgreementAnswerNotice = (
    { patientId, instrument, practiceId, enabled = true }: {
        patientId?: string;
        instrument: ConsentInstrumentId;
        practiceId: () => string | undefined;
        enabled?: boolean;
    },
    onNotice: () => void,
    onReturn?: () => void,
): void => {
    const socket = useOptionalWebSocketServiceContext();
    const subscribe = socket?.subscribe;
    const unsubscribe = socket?.unsubscribe;
    const latest = useRef({ onNotice, practiceId });
    latest.current = { onNotice, practiceId };
    const listening = enabled && Boolean(patientId);

    useEffect(() => (listening ? onRecordAuthorizationAnswer(() => latest.current.onNotice()) : undefined), [listening]);

    useEffect(() => {
        if (!listening || !patientId || !subscribe || !unsubscribe) return undefined;
        const heard = (notice: AuthorizationAnswerNotice) => {
            if (isRecordAnswerFor(notice, patientId, latest.current.practiceId(), instrument)) latest.current.onNotice();
        };
        subscribe(AUTHORIZATION_ANSWER_EVENT, heard);
        return () => unsubscribe(AUTHORIZATION_ANSWER_EVENT, heard);
    }, [listening, patientId, instrument, subscribe, unsubscribe]);

    useRereadOnReturn(() => onReturn?.(), listening && Boolean(onReturn));
};