/**
 * Chat utilities
 */
import type { ListItemData } from '@gravity-ui/uikit';
import type { ChatType, ListItemChatData } from "../types/index.js";
/**
 * Groups chats by date
 *
 * @param chats - Array of chats to group
 * @returns Map of date keys to chat arrays
 */
export declare function groupChatsByDate(chats: ChatType[]): Map<string, ChatType[]>;
/**
 * Filter function type for chat list
 */
export type ChatFilterFunction = (filter: string) => (item: ListItemData<ListItemChatData>) => boolean;
/**
 * Default filter function - searches in chat name and last message
 *
 * @param filter - Search query string
 * @returns Function that filters list items
 */
export declare function defaultChatFilter(filter: string): (item: ListItemData<ListItemChatData>) => boolean;