/**
 * useScrollPreservation — manage the message list's scroll behaviour:
 *
 * 1. Auto-scroll to bottom when:
 *    - The user was already near the bottom AND a new message arrived
 *    - The user just sent a message (trailing `user` row appears)
 *    - An AI/agent bubble is streaming (content length grows)
 *    - The conversation first mounts
 * 2. Preserve scroll position when the user has scrolled up (reading history)
 *    and new agent/AI messages arrive — instead, surface the
 *    "↓ N new messages" pill.
 * 3. Detect when the user manually scrolls back to the bottom and reset the
 *    "scrolled up" flag + clear the pill counter.
 */
import type { RefObject } from "preact";
import type { ChatMessage } from "../../../../utils/globals";
import type { ChatStore } from "../../store/chat-store";
interface UseScrollPreservationArgs {
    store: ChatStore;
    scrollRef: RefObject<HTMLElement | null>;
    messages: ChatMessage[];
    /**
     * Whether the trailing typing bubble is currently rendered. When it
     * flips from `false` → `true` the bubble grows the list by ~one
     * message-height; if the user was at the bottom we snap them to keep
     * the dots in view, matching the behaviour for newly-arrived
     * messages.
     */
    typingActive?: boolean;
}
export declare function useScrollPreservation({ store, scrollRef, messages, typingActive, }: UseScrollPreservationArgs): {
    jumpToBottom: () => void;
};
export {};