import { type MutableRefObject, type UIEvent } from 'react';
/**
 * Configuration for tracking action button overlap and scroll state.
 *
 * @private component of `<Chat/>`
 */
export type ChatActionsOverlapConfig = {
    /**
     * Provides the chat messages container ref for auto-scroll integration.
     */
    chatMessagesRef: (element: HTMLDivElement | null) => void;
    /**
     * Scroll handler from the auto-scroll hook.
     */
    handleScroll: (event: UIEvent<HTMLDivElement>) => void;
    /**
     * Selector used to locate message elements for overlap checks.
     */
    messageSelector: string;
    /**
     * Optional selector for the actual message content region used for overlap checks.
     *
     * When not provided or when no matching element is found, the full message element is used.
     */
    messageCollisionSelector?: string;
    /**
     * Messages used to trigger overlap recalculation.
     */
    messages: ReadonlyArray<unknown>;
};
/**
 * Result returned by the action overlap tracking hook.
 */
export type ChatActionsOverlapResult = {
    /**
     * Ref for the actions toolbar element.
     */
    actionsRef: MutableRefObject<HTMLDivElement | null>;
    /**
     * Combined ref setter for chat messages (auto-scroll + overlap tracking).
     */
    setChatMessagesElement: (element: HTMLDivElement | null) => void;
    /**
     * Scroll handler that updates both auto-scroll and overlap state.
     */
    handleChatScroll: (event: UIEvent<HTMLDivElement>) => void;
    /**
     * Whether the actions toolbar is currently being scrolled.
     */
    isActionsScrolling: boolean;
    /**
     * Whether the actions toolbar overlaps the first visible message.
     */
    isActionsOverlapping: boolean;
};
/**
 * Tracks action toolbar overlap while coordinating with chat auto-scroll.
 *
 * @private component of `<Chat/>`
 */
export declare function useChatActionsOverlap(config: ChatActionsOverlapConfig): ChatActionsOverlapResult;