export default function searchUsers(action$) {
  return action$
    .ofType(ActionTypes.SEARCHED_USERS)
    .map((action) => action.payload.query)
    .filter((q) => !!q)
    .switchMap((q) =>
      Observable.timer(800) // debounce
        .takeUntil(action$.ofType(ActionTypes.CLEARED_SEARCH_RESULTS))
        .mergeMap(() =>
          Observable.merge(
            Observable.of(replace(`?q=${q}`)),
            ajax
              .getJSON(`https://api.github.com/search/users?q=${q}`)
              .map((res) => res.items)
              .map(receiveUsers),
          ),
        ),
    );
}