import { Subject, from } from 'rxjs';
import { groupBy, mergeMap } from 'rxjs/operators';

// Sample response data
const responseData = [
  { who: 'user1', message: 'Hello from user1' },
  { who: 'user2', message: 'Hi there from user2' },
  { who: 'user1', message: 'Another message from user1' },
  { who: 'user3', message: 'Message from user3' },
];

// Create a Subject to receive the response
const responseSubject = new Subject();

// Use groupBy to split the response into observables based on 'who'
const groupedSubjects: Record<string, Subject<any>> = {};

// Create Observables based on 'who' property
const groupedObservables = responseData.map((message) => {
  if (!groupedSubjects[message.who]) {
    groupedSubjects[message.who] = new Subject();
  }
  return groupedSubjects[message.who].asObservable();
});

// Merge all Observables into a single stream
from(groupedObservables)
  .pipe(
    mergeMap((obs) => obs)
  )
  .subscribe((message) => {
    console.log(`Received message from ${message.who}: ${message.message}`);
  });

// Push data into the responseSubject
responseData.forEach((data) => {
  responseSubject.next(data);
});