import { Unsubscribe } from './integration.js';
/** Attribute whose value names the theme to prefetch on hover/focus. */
export declare const PREFETCH_TRIGGER_ATTRIBUTE = "data-theme-preview";
/**
 * Checks whether a theme's stylesheet is already present in the document.
 *
 * Recognises both links owned by the selector (`theme-<id>-css`) and the
 * blocking script's FOUC-prevention link when it points at the theme.
 *
 * @param documentObj - Document to inspect
 * @param themeId - Theme whose stylesheet to look for
 * @returns True when the theme's CSS is already linked
 */
export declare function isThemeCSSLoaded(documentObj: Document, themeId: string): boolean;
/**
 * Decides whether a theme's CSS needs an on-demand load.
 *
 * @param documentObj - Document to inspect
 * @param themeId - Theme the page is about to switch to
 * @returns True when the theme is known and its CSS is not yet linked
 */
export declare function shouldLoadThemeCSS(documentObj: Document, themeId: string): boolean;
/**
 * Loads a theme's CSS on demand through the selector's loader.
 *
 * Injects the stylesheet link at most once: repeat calls for a theme
 * whose CSS is already linked are no-ops that resolve to true. Unknown
 * or malformed theme IDs are rejected without touching the document.
 *
 * @param documentObj - Document to load the stylesheet into
 * @param themeId - Theme whose CSS to load
 * @returns True when the CSS is available (loaded now or previously)
 */
export declare function loadThemeCSSOnDemand(documentObj: Document, themeId: string): Promise<boolean>;
/**
 * Prefetches a theme's CSS so a later switch hits the browser cache.
 *
 * Injects a `<link rel="prefetch" as="style">` at most once per theme.
 * Skips themes whose stylesheet is already linked, themes already
 * prefetched, and unknown theme IDs.
 *
 * @param documentObj - Document to inject the prefetch link into
 * @param themeId - Theme whose CSS to prefetch
 * @returns True when a prefetch link was injected by this call
 */
export declare function prefetchThemeCSS(documentObj: Document, themeId: string): boolean;
/**
 * Wires hover/focus-triggered CSS prefetch for marked elements.
 *
 * Listens for `mouseover` and `focusin` on the document and prefetches
 * the theme named by the nearest ancestor carrying the
 * `data-theme-preview` attribute. Delegation means marquee items added
 * after wiring are covered without re-wiring.
 *
 * @param documentObj - Document to listen on (defaults to global)
 * @returns Function that removes the listeners when called
 */
export declare function wireHoverPrefetch(documentObj?: Document): Unsubscribe;
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