import { type ReactNode, type RefObject } from "react";
type LightboxController = {
    open: (src: string, caption?: string, source?: HTMLElement | null, label?: string, downloadFilename?: string, controlLabels?: LightboxControlLabels, releaseSource?: () => void) => void;
};
export type LightboxControlLabels = {
    download?: string | undefined;
    close?: string | undefined;
    previous?: string | undefined;
    next?: string | undefined;
};
/** One image the open lightbox can page to, resolved only when it is shown. */
export type LightboxGalleryImage = {
    src: string;
    caption?: string | undefined;
    label?: string | undefined;
    /** Releases a source owned by this load, such as an object URL. */
    release?: (() => void) | undefined;
};
export type LightboxGalleryEntry = {
    /** Whether this entry currently resolves to an image; defaults to yes. */
    isImage?: (() => Promise<boolean>) | undefined;
    load: () => Promise<LightboxGalleryImage | null>;
};
/**
 * Adds the element's image to the lightbox gallery so an open lightbox can page
 * to it with the arrow controls, in document order. The entry is resolved only
 * when it is shown, so deferred images that never scrolled into view still page.
 * A lightbox opened from inside the element starts at this entry.
 */
export declare function useLightboxGalleryItem(ref: RefObject<HTMLElement | null>, entry: LightboxGalleryEntry | null): void;
/** Open the app-level screenshot lightbox. No-op outside a `LightboxProvider`. */
export declare function useLightbox(): LightboxController;
/**
 * The lightbox controller when one is mounted, or `null` outside a
 * `LightboxProvider`. Lets a media primitive degrade to a non-interactive image
 * (rather than a dead "Expand" button that announces an action it cannot do).
 */
export declare function useLightboxOptional(): LightboxController | null;
/** @internal Owns one optional retained lightbox source and releases it exactly once. */
export declare function createLightboxSourceOwner(): {
    replace(release?: (() => void) | undefined): void;
    release(): void;
};
/**
 * The app-level screenshot lightbox. Render once near the timeline; renderers
 * call `useLightbox().open(src)`.
 *
 * Idempotent by design: when an ancestor `LightboxProvider` already exists (e.g.
 * a `MessageTimeline` mounted inside an app that already wraps its shell), this
 * one becomes a pass-through and does NOT mount a second focus-trapping Dialog.
 * That keeps `MessageTimeline` self-sufficient (it owns its own provider) while
 * composing cleanly when nested.
 */
export declare function LightboxProvider({ children }: {
    children: ReactNode;
}): import("react").JSX.Element;
/** @internal Exact controls rendered by an open screenshot lightbox. */
export declare function ScreenshotLightboxControls({ src, downloadFilename, controlLabels, }: {
    src: string;
    downloadFilename?: string | undefined;
    controlLabels?: LightboxControlLabels | undefined;
}): import("react").JSX.Element;
export {};