import { useEffect } from 'react';
import { Task } from 'fhir/r4';
import {
    useTaskServiceContext,
    useFhirServiceContext,
    usePatientServiceContext,
    useWebSocketServiceContext
} from '../services';
import { isArchived } from '../utils/archivedResource';

export const useFhirTaskBroadcast = () => {
    const { subscribe, unsubscribe } = useWebSocketServiceContext();
    const { setTasksList } = useTaskServiceContext();
    const { patientState } = usePatientServiceContext();
    const { extractReferenceId } = useFhirServiceContext();

    useEffect(() => {
        if (!patientState) {
            return;
        }

        const handleTaskEvent = (cloudEvent: any) => {
            const task: Task = cloudEvent.data;
            const eventType = cloudEvent.type;

            if (!task?.id) {
                return;
            }
            const patientId = extractReferenceId(task.for);

            if (patientState.id === patientId) {
                switch (eventType) {
                    case 'com.akashichealthrecords.fhir.task.created':
                        setTasksList(prev => [
                            task,
                            ...prev.filter(existingTask => existingTask.id !== task.id)
                        ]);
                        break;
                    case 'com.akashichealthrecords.fhir.task.updated':
                        setTasksList(prev => {
                            if (isArchived(task)) {
                                return prev.filter(existingTask => existingTask.id !== task.id);
                            }

                            const taskExists = prev.some(existingTask => existingTask.id === task.id);

                            if (!taskExists) {
                                return [task, ...prev];
                            }

                            return prev.map(existingTask =>
                                existingTask.id === task.id ? task : existingTask
                            );
                        });
                        break;
                    case 'com.akashichealthrecords.fhir.task.deleted':
                        setTasksList(prev => prev.filter(p => p.id !== task.id));
                        break;
                }
            }
        };

        subscribe('com.akashichealthrecords.fhir.task.created', handleTaskEvent);
        subscribe('com.akashichealthrecords.fhir.task.updated', handleTaskEvent);
        subscribe('com.akashichealthrecords.fhir.task.deleted', handleTaskEvent);

        return () => {
            unsubscribe('com.akashichealthrecords.fhir.task.created', handleTaskEvent);
            unsubscribe('com.akashichealthrecords.fhir.task.updated', handleTaskEvent);
            unsubscribe('com.akashichealthrecords.fhir.task.deleted', handleTaskEvent);
        };
    }, [patientState, subscribe, unsubscribe, extractReferenceId, setTasksList]);
};