import { useEffect, useRef } from 'react';
import { useWebSocketServiceContext } from '../services';
import { useCapabilityServiceContext } from '../services/CapabilityService.tsx';
import { useFormSubmissionNotificationContext } from '../services/FormSubmissionNotificationService.tsx';
import { useFirstSignInGateStatus } from '../components/FirstSignInGate/firstSignInGateStatus.tsx';
import { isStaffExperience } from '../utils/mountContext.ts';

// Re-reads rather than bumping the count, so the rail's rows and count stay one snapshot.
// Nothing is read behind an unanswered agreement; a broadcast that arrives then is read once it clears.
const mayReadForms = (mayCall: (method: string, path: string) => boolean | undefined) =>
    isStaffExperience() && mayCall('GET', '/form-submissions') !== false;

export const useFhirFormSubmissionBroadcast = () => {
    const { subscribe, unsubscribe } = useWebSocketServiceContext();
    const { refresh } = useFormSubmissionNotificationContext();
    const { mayCall } = useCapabilityServiceContext();
    const gate = useFirstSignInGateStatus();
    const held = useRef(false);
    useEffect(() => {
        const handler = () => {
            if (!mayReadForms(mayCall)) return;
            if (gate !== 'clear') {
                held.current = true;
                return;
            }
            void refresh();
        };
        subscribe('com.akashichealthrecords.fhir.formsubmission.created', handler);
        return () => unsubscribe('com.akashichealthrecords.fhir.formsubmission.created', handler);
    }, [subscribe, unsubscribe, refresh, mayCall, gate]);
    useEffect(() => {
        if (gate !== 'clear' || !held.current) return;
        held.current = false;
        // Asked again: what this person may read can have changed while the event waited.
        if (mayReadForms(mayCall)) void refresh();
    }, [gate, refresh, mayCall]);
};