import { Subject } from 'rxjs';
import type { RequestData, ResponseData } from './trpc';

export const clientFunctionCallEventSubjectMap = new Map<number, Subject<RequestData>>();

/**
 * Clear client function call event subjects.
 * If socketId is not undefined or 0, clear all the client function call event subjects.
 * Otherwise, clear the client function call event subjects by socketId.
 * @param socketId The id of socket.
 */
export const clearClientFunctionCallEventSubjects = (socketId?: number) => {
  if (socketId) {
    clientFunctionCallEventSubjectMap.get(socketId)?.unsubscribe();
    clientFunctionCallEventSubjectMap.delete(socketId);
  } else {
    // Clear all the client function call event subjects.
    for (const subject of clientFunctionCallEventSubjectMap.values()) {
      subject.unsubscribe();
    }
    clientFunctionCallEventSubjectMap.clear();
  }
};

/**
 * Get a client function call event subject by socketId.
 * If there is no cached subject which key is socketId, create an new subject, cache it with socketId and return it.
 * @param socketId The id of socket.
 * @returns The cached subject which key is socketId.
 */
export const getClientFunctionCallEventSubject = (socketId: number) => {
  let subject = clientFunctionCallEventSubjectMap.get(socketId);
  if (subject) {
    return subject;
  }

  subject = new Subject<RequestData>();
  clientFunctionCallEventSubjectMap.set(socketId, subject);
  return subject;
};

export const clientFunctionReturnEventSubject = new Subject<ResponseData>();