import { type UpdateCheckCache } from '../update/notice.js';
/** What the banner needs to write its sentence, or null when there is nothing to say. */
export interface CliUpdateState {
    current: string;
    latest: string;
}
/**
 * How often the cache file is re-read.
 *
 * Not about the network — the refresh below has its own, much longer interval — but about not
 * stat-ing and parsing a file 7200 times an hour to answer a question whose answer changes at most
 * a few times a day.
 */
export declare const CLI_UPDATE_READ_INTERVAL_MS = 30000;
export interface CliUpdateReaderDeps {
    version: () => string;
    readCache: () => UpdateCheckCache | null;
    /** Fire-and-forget; self-throttles on the cache's own staleness rule. */
    refresh: (version: string) => void;
    now: () => number;
}
export declare const defaultCliUpdateReaderDeps: CliUpdateReaderDeps;
/**
 * A memoised "is this CLI behind?", safe to call from a route handler on every poll.
 *
 * The refresh is triggered from here rather than on a timer of its own, because a `dev` session is
 * exactly the case bin.ts's one-shot refresh does not cover: it checks once at startup and the
 * process then runs for hours, so without this a session started before a release would never
 * learn of it. `refreshUpdateCacheInBackground` already declines to do anything until its own
 * interval has passed, so calling it here every thirty seconds costs a cache read, not a request.
 */
export declare function createCliUpdateReader(deps?: CliUpdateReaderDeps): () => CliUpdateState | null;