/**
 * Shareable URL state — a keyed map of app view state that round-trips through
 * the host page's `state` query param, so the address bar is always a link to
 * the current view.
 *
 * Inside the Lightdash iframe the seed arrives synchronously in the hash
 * (written there by the host from its own `?state=`) and changes are posted to
 * the parent; top-level (local dev) the app reads and writes its own `?state=`.
 * See the "Shareable URL state" section of docs/data-apps.md.
 *
 * Seeded values come from a user-editable URL — treat them as untrusted.
 */
export type UrlStateMap = Record<string, unknown>;
/** Iframe → parent. The host writes `state` into its page URL. */
export type SdkUrlStateChangeMessage = {
    type: 'lightdash:sdk:url-state-change';
    state: UrlStateMap;
};
export declare const URL_STATE_CHANGE_MESSAGE = "lightdash:sdk:url-state-change";
export declare const URL_STATE_PARAM = "state";
/** Keep in sync with the parent-side caps in useAppSdkBridge and
 *  useAppUrlStateSync (packages/frontend). */
export declare const MAX_URL_STATE_CHARS = 4096;
/**
 * Parse the seed map. The iframe hash wins (that's where the host forwards its
 * `?state=`); the search param is the top-level fallback.
 */
export declare function parseUrlStateSeed(location: {
    hash: string;
    search: string;
}): UrlStateMap;
/**
 * Serialize a state map, or null when it can't be published (non-JSON values,
 * or over the size cap). Warns so the author sees why state stopped persisting.
 */
export declare function serializeUrlState(state: UrlStateMap): string | null;
export type UrlStateStore = {
    getState: () => UrlStateMap;
    setKey: (key: string, value: unknown) => void;
    subscribe: (listener: () => void) => () => void;
};
/**
 * Minimal external store: synchronous reads for useSyncExternalStore, trailing-
 * edge publish on writes. Exported for tests — app code uses `useUrlState`.
 */
export declare function createUrlStateStore(options: {
    seed: UrlStateMap;
    publish: (state: UrlStateMap) => void;
    debounceMs?: number;
}): UrlStateStore;
/**
 * `useState`-shaped hook whose value round-trips through the page URL:
 *
 *   const [period, setPeriod] = useUrlState('period', 'last_month');
 *
 * Values must be JSON-serializable. All call sites share one map keyed by
 * `key`, so no provider is needed.
 */
export declare function useUrlState<T>(key: string, defaultValue: T): [T, (next: T | ((prev: T) => T)) => void];