import type { Snapshot } from "./types.js";
/**
 * Per-session snapshot file: `<sessionId>.undo-snapshots.json`.
 * Deliberately NOT `.jsonl` — pi treats every `*.jsonl` file in a session dir
 * as a session, so a `.jsonl` snapshot file would show up as a bogus session.
 */
export declare const SNAPSHOT_FILE_SUFFIX = ".undo-snapshots.json";
export declare function snapshotFilePath(sessionDir: string, sessionId: string): string;
export declare function loadSnapshots(filePath: string): Promise<Snapshot[]>;
export declare function appendSnapshot(filePath: string, snapshot: Snapshot): Promise<void>;
/**
 * Remove snapshot files for sessions that no longer exist. pi deletes a session
 * by removing its `.jsonl` file directly (no event fires), so orphaned snapshot
 * files are cleaned up here whenever any session in the directory starts.
 * The current session is never removed. Returns the names of deleted files.
 */
export declare function sweepOrphanedSnapshots(sessionDir: string, currentSessionId?: string): Promise<string[]>;