import type { VersionUpdate } from "@oh-my-pi/pi-tui/prompt/welcome";
/** A finished attempt at a version holds off the next attempt at that version this long. */
export declare const RETRY_AFTER_MS: number;
/** Worker phases; `done`, `current`, and `failed` end a run. */
export type AutoUpdatePhase = "checking" | "downloading" | "installing" | "done" | "current" | "failed";
/** The worker's status file. */
export interface AutoUpdateState {
    phase: AutoUpdatePhase;
    /** Version the spawning launch's check offered; keys the retry hold-off. */
    target?: string;
    /** Version being installed, or (`done`) the version the PATH launcher now reports. */
    version?: string;
    /** Bytes downloaded so far of `total` (`downloading`). */
    received?: number;
    total?: number;
    /** Why the run failed. */
    error?: string;
    /** `Date.now()` at the write. */
    at: number;
}
/** Where {@link runAutoUpdate} reports. */
export interface AutoUpdateSinks {
    /** Show, or with `null` clear, the indicator after the welcome banner's version. */
    show(update: VersionUpdate | null): void;
    /** Fall back to the startup notice that tells the user to run `omp update`. */
    notify(version: string): void;
}
/** What the welcome banner shows for a worker's `state`; null when nothing (no update, or no version to name). */
export declare function describeAutoUpdate(state: AutoUpdateState): VersionUpdate | null;
/**
 * Whether a launch whose check offered `target` starts a worker, given the
 * status `last` left by the previous run: always for a new version, else once
 * that run is {@link RETRY_AFTER_MS} old, however it ended.
 */
export declare function shouldStartWorker(last: AutoUpdateState | undefined, target: string, now?: number): boolean;
/**
 * Launch side of auto-update. Follows a worker another launch already runs;
 * otherwise, once `check` resolves to a newer version, starts a worker, unless
 * a recent attempt at that version finished: then it shows that attempt's
 * install as ready, or after a failure the startup notice. Where omp cannot
 * update itself (Tern, Nix, a source checkout) the check only feeds the notice.
 * Resolves when the worker ends or nothing needs doing; never throws.
 */
export declare function runAutoUpdate(check: Promise<string | undefined>, sinks: AutoUpdateSinks): Promise<void>;
/**
 * Worker entry (`__omp_worker_auto_update`): install the newest release the
 * way `omp update` would, mirroring progress into the status file, and record
 * the outcome. Exits at once when another worker holds the status lock.
 */
export declare function runAutoUpdateWorker(): Promise<never>;