RocketChat/Rocket.Chat

import type { IRoom } from '@rocket.chat/core-typings';
import { isDirectMessageRoom } from '@rocket.chat/core-typings';

import { useRoomName } from '../../../../../hooks/useRoomName';

export const useMessageBoxPlaceholder = (placeholder: string, room?: IRoom) => {
    if (!room) {
        throw new Error('In order to get the placeholder a `room` must be provided');
    }

    const roomName = useRoomName(room);

    if (isDirectMessageRoom(room)) {
        return `${placeholder} @${roomName}`;
    }

    return `${placeholder} #${roomName}`;
};