import { useCallback, useEffect, useMemo, useState } from 'react';
import * as uuid from 'uuid';
import CombinedGuild from '../../guild-combined';
import GuildsManager from "../../guilds-manager";

// Subscribes to changes in the list of guilds in the manager
function useGuildListSubscription(guildsManager: GuildsManager): [ guilds: CombinedGuild[] ] {
	const [ refreshId, setRefreshId ] = useState<string>(uuid.v4());

	const refresh = useCallback(() => {
		setRefreshId(uuid.v4());
	}, []);

	useEffect(() => {
		guildsManager.on('update-guilds', refresh);
		return () => {
			guildsManager.off('update-guilds', refresh);
		}
	}, []);

	const guilds = useMemo(() => {
		return guildsManager.guilds.slice();
	}, [ refreshId ]);

	return [ guilds ];
}