import { HoistService, InitContext } from '@xh/hoist/core';
/**
 * Service to read and set user-specific preference values.
 *
 * Server-side preference support is provided by hoist-core. Preferences must be predefined on the
 * server (they can be managed via the Admin console) and are referenced by their string key. They
 * are assigned default values that apply to users who have yet to have a value set that is specific
 * to their account. Once set, however, the user will get their customized value instead of the
 * default going forwards.
 *
 * This could happen via an explicit option the user adjusts, or happen transparently based on a
 * natural user action or component integration (e.g. collapsing or resizing a `Resizable` that has
 * been configured with preference support).
 *
 * Preferences are persisted automatically back to the server by default so as to follow their user
 * across workstations.
 */
export declare class PrefService extends HoistService {
    telemetryPrefix: string;
    static instance: PrefService;
    private _data;
    private _updates;
    initAsync(ctx: InitContext): Promise<void>;
    /**
     * Check to see if a given preference has been *defined*.
     */
    hasKey(key: string): boolean;
    /**
     * Check whether the current user has an explicit value on file for the given preference, vs.
     * receiving the preference's server-side default value.
     *
     * @param key - unique key used to identify the pref.
     */
    isSet(key: string): boolean;
    /**
     * Get the value for a given key, either the user-specific value (if set) or the default.
     * Typically accessed via the convenience alias {@link XH.getPref}.
     *
     * @param key - unique key used to identify the pref.
     * @param defaultValue - value to return if the preference key is not found - i.e.
     *      the config has not been created on the server - instead of throwing. Use sparingly!
     *      In general, it's better to not provide defaults here, but instead keep entries updated
     *      via the Admin client and have it be obvious when one is missing.
     */
    get(key: string, defaultValue?: any): any;
    /**
     * Set a preference value for the current user.
     * Typically accessed via the convenience alias {@link XH.setPref}.
     *
     * Values are validated client-side to ensure they (probably) are of the correct data type.
     *
     * Values are saved to the server in an asynchronous and debounced manner.
     * See pushAsync() and pushPendingAsync()
     */
    set(key: string, value: any): void;
    /**
     * Restore a preference to its default value, clearing the user's explicit value on the server.
     *
     * Unlike `set()`, this clears the user's explicit value rather than persisting the default as
     * one - so {@link isSet} will report `false` afterwards. Saved asynchronously (see `set()`).
     */
    unset(key: string): void;
    /**
     * Set a preference value for the current user, and immediately trigger a sync to the server.
     *
     * Useful when important to verify that the preference has been fully round-tripped - e.g.
     * before making another call that relies on its updated value being read on the server.
     */
    pushAsync(key: string, value: any): Promise<void>;
    /**
     * Push any pending buffered updates to persist newly set values to the server.
     *
     * Not typically called by applications.  Called automatically by the framework after changes
     * and when page is hidden/terminated.
     */
    pushPendingAsync(): Promise<void>;
    private pushPendingBuffered;
    private loadPrefsAsync;
    private ensureKeyExists;
    private validateBeforeSet;
    private valueIsOfType;
}