/**
 * FileStore — generic interface for atomic JSON file persistence.
 *
 * Encapsulates the common "read JSON → modify → atomic write" pattern
 * used throughout core modules. Implementations handle:
 * - Missing file → default data
 * - Malformed file → default data (graceful degradation)
 * - Atomic writes via temp + rename
 */
export interface FileStore<T> {
    /** Load data from file, returning defaults if missing or corrupt. */
    load(): T;
    /** Atomically write data to file. */
    save(data: T): void;
    /**
     * Read-modify-write cycle.
     * The mutate function receives current data and may modify it in place.
     * The modified data is saved automatically after fn completes.
     * If fn throws, the write is aborted and the file is unchanged.
     *
     * Returns the value returned by fn (useful for extracting computed results).
     *
     * NOTE: This method is NOT thread-safe. Caller must ensure no concurrent
     * writes to the same file — use withLock() or equivalent to serialize access.
     */
    mutate<R>(fn: (data: T) => R): R;
}
/**
 * JSON-backed FileStore implementation.
 *
 * Uses atomicWriteFileSync for crash-safe writes.
 * Handles missing/corrupt files by returning the provided default factory result.
 */
export declare class JsonFileStore<T extends object> implements FileStore<T> {
    private readonly filePath;
    private readonly defaultFactory;
    constructor(filePath: string, defaultFactory: () => T);
    load(): T;
    save(data: T): void;
    mutate<R>(fn: (data: T) => R): R;
}