import { useEffect } from 'react';
import { Practitioner } from 'fhir/r4';
import {
    usePractitionerServiceContext,
    useFhirServiceContext,
    useWebSocketServiceContext
} from '../services';

export const useFhirPractitionerBroadcast = () => {
    const { subscribe, unsubscribe } = useWebSocketServiceContext();
    const { setPractitionersList } = usePractitionerServiceContext();
    const { extractReferenceId } = useFhirServiceContext();

    useEffect(() => {
        const handlePractitionerEvent = (cloudEvent: any) => {

            const eventType = cloudEvent.type;

            switch (eventType) {
                case 'com.akashichealthrecords.fhir.practitioner.created':
                    const { practitioner: createdPractitioner, practitionerRole } = cloudEvent.data;

                    if (createdPractitioner?.id) {
                        console.log('Processing Practitioner create event for practitioner:', createdPractitioner.id);

                        // Same race as every other created append, one level deeper: the id
                        // lives at `.practitioner.id`, which is exactly where the `updated` arm below
                        // already looks. Without this a practitioner the staff-list refetch had already
                        // brought in appeared twice in the directory.
                        //
                        // SKIPS rather than replaces, which is the opposite choice to the other hooks
                        // and is deliberate: this event carries at most ONE role, so the entry built here
                        // is `roles: [thatOne]`. Replacing an existing entry would throw away every other
                        // role the refetch already knew about - trading a duplicate row for a silently
                        // truncated one, which is harder to notice and worse.
                        setPractitionersList(prev =>
                            prev.some(entry => entry.practitioner.id === createdPractitioner.id)
                                ? prev
                                : [
                                    ...prev,
                                    {
                                        practitioner: createdPractitioner,
                                        roles: practitionerRole ? [practitionerRole] : []
                                    }
                                ]
                        );
                    }
                    break;

                case 'com.akashichealthrecords.fhir.practitioner.updated':
                    const updatedPractitioner: Practitioner = cloudEvent.data;

                    if (updatedPractitioner?.id) {
                        console.log('Processing Practitioner update event for practitioner:', updatedPractitioner.id);

                        setPractitionersList(prev =>
                            prev.map(practitionerWithRoles =>
                                practitionerWithRoles.practitioner.id === updatedPractitioner.id
                                    ? { ...practitionerWithRoles, practitioner: updatedPractitioner }
                                    : practitionerWithRoles
                            )
                        );
                    }
                    break;
            }
        };

        subscribe('com.akashichealthrecords.fhir.practitioner.created', handlePractitionerEvent);
        subscribe('com.akashichealthrecords.fhir.practitioner.updated', handlePractitionerEvent);

        return () => {
            unsubscribe('com.akashichealthrecords.fhir.practitioner.created', handlePractitionerEvent);
            unsubscribe('com.akashichealthrecords.fhir.practitioner.updated', handlePractitionerEvent);
        };
    }, [subscribe, unsubscribe, extractReferenceId, setPractitionersList]);
};