/**
 * WidgetCacheManager — In-memory cache with IndexedDB persistence for widget data.
 *
 * Architecture:
 *   - **Reads** are synchronous from in-memory Maps (fastest possible lookup).
 *   - **Writes** update the in-memory Map immediately, then persist to IndexedDB
 *     in the background (fire-and-forget) so data survives page reloads.
 *   - **On startup**, `init()` loads all persisted data from IndexedDB into the Maps.
 *
 * This gives us the speed of in-memory access (no async overhead, no JSON.parse)
 * with the durability of IndexedDB (no 5 MB limit, survives reloads).
 *
 * Three separate caches are maintained:
 *   - **widgetMap**  — standard widget data keyed by widget ID
 *   - **latestMap**  — latest published version keyed by origin ID
 *   - **recentMap**  — recent published version keyed by origin ID
 */
export declare class WidgetCacheManager {
    /** In-memory cache for standard widget data */
    private static widgetMap;
    /** In-memory cache for latest-version widget data */
    private static latestMap;
    /** In-memory cache for recent-version widget data */
    private static recentMap;
    /**
     * Loads all persisted widget cache data from IndexedDB into memory.
     * Called automatically during `init()` / `initConceptConnection()`.
     * Safe to call multiple times — just overwrites the Maps.
     *
     * Skips entirely when `Environments.getValue('enableCache', true)` is `false`,
     * keeping all three maps empty so no stale data is ever served.
     */
    static init(): Promise<void>;
    /**
     * Retrieves cached widget data by widget ID (synchronous, from memory).
     * Returns `null` when cache is disabled via `Environments.setValue('enableCache', false)`,
     * causing `BuildWidgetFromId` to always fetch fresh from the backend.
     * @param id - The widget ID to look up
     * @returns The cached data object, or null if not cached or cache is disabled
     */
    static getWidget(id: number): any | null;
    /**
     * Stores widget data in memory and persists to IndexedDB in the background.
     * No-ops when cache is disabled via `Environments.setValue('enableCache', false)`.
     * Skips if data is identical to what's already cached (dedup guard).
     * @param id - The widget ID
     * @param data - The widget data object to cache
     */
    static setWidget(id: number, data: any): void;
    /**
     * Removes a single widget entry from memory and IndexedDB.
     * @param id - The widget ID to remove
     */
    static removeWidget(id: number): void;
    /**
     * Retrieves cached latest-version widget data (synchronous, from memory).
     * Returns `null` when cache is disabled, causing a live backend fetch.
     * @param id - The origin widget ID
     * @returns The cached data object, or null if not cached or cache is disabled
     */
    static getLatest(id: number): any | null;
    /**
     * Stores latest-version widget data in memory and persists to IndexedDB.
     * No-ops when cache is disabled. Skips if data is identical to what's already cached.
     * @param id - The origin widget ID
     * @param data - The latest widget data to cache
     */
    static setLatest(id: number, data: any): void;
    /**
     * Removes a single latest-version entry from memory and IndexedDB.
     * @param id - The origin widget ID to remove
     */
    static removeLatest(id: number): void;
    /**
     * Retrieves cached recent-version widget data (synchronous, from memory).
     * Returns `null` when cache is disabled, causing a live backend fetch.
     * @param id - The origin widget ID
     * @returns The cached data object, or null if not cached or cache is disabled
     */
    static getRecent(id: number): any | null;
    /**
     * Stores recent-version widget data in memory and persists to IndexedDB.
     * No-ops when cache is disabled. Skips if data is identical to what's already cached.
     * @param id - The origin widget ID
     * @param data - The recent widget data to cache
     */
    static setRecent(id: number, data: any): void;
    /**
     * Removes a single recent-version entry from memory and IndexedDB.
     * @param id - The origin widget ID to remove
     */
    static removeRecent(id: number): void;
    /**
     * Clears all three widget caches from both memory and IndexedDB.
     * Useful for cache invalidation on logout or environment switch.
     */
    static clearAll(): void;
    /**
     * Checks if the new data is identical to what's already in the Map.
     * Prevents unnecessary IndexedDB writes when data hasn't changed.
     *
     * @param map - The in-memory Map to check against
     * @param id - The key to check
     * @param data - The new data to compare
     * @returns true if data is a duplicate (should be skipped)
     */
    private static _isDuplicate;
}