/**
 * Registry Manifest Cache
 *
 * Implements TTL-based caching for registry manifests to reduce network requests.
 * Cache location: ~/.fractary/registry/cache/
 */
import type { RegistryManifest } from './types.js';
/**
 * Cached manifest entry with metadata
 */
export interface ManifestCache {
    /** Original registry URL */
    url: string;
    /** Cached manifest data */
    manifest: RegistryManifest;
    /** Unix timestamp when fetched (milliseconds) */
    fetched_at: number;
    /** Time-to-live in seconds */
    ttl: number;
}
/**
 * Cache statistics for monitoring
 */
export interface CacheStats {
    /** Total number of cached entries */
    total_entries: number;
    /** Number of fresh (valid) entries */
    fresh_entries: number;
    /** Number of expired entries */
    expired_entries: number;
    /** Total cache size in bytes */
    total_size_bytes: number;
    /** Cache directory path */
    cache_dir: string;
}
export declare class ManifestCacheManager {
    private cacheDir;
    constructor(cacheDir?: string);
    /**
     * Get cache file path for a registry
     */
    private getCachePath;
    /**
     * Ensure cache directory exists
     */
    private ensureCacheDir;
    /**
     * Get cached manifest if fresh
     * @returns Cached manifest if exists and fresh, null otherwise
     */
    get(registryName: string): Promise<RegistryManifest | null>;
    /**
     * Store manifest in cache
     */
    set(registryName: string, url: string, manifest: RegistryManifest, ttl?: number): Promise<void>;
    /**
     * Check if cached entry is fresh (not expired)
     */
    isFresh(cache: ManifestCache): boolean;
    /**
     * Get age of cached entry in seconds
     */
    getAge(cache: ManifestCache): number;
    /**
     * Invalidate (delete) cache for a registry
     */
    invalidate(registryName: string): Promise<void>;
    /**
     * Invalidate all cached manifests
     */
    invalidateAll(): Promise<void>;
    /**
     * List all cached registry names
     */
    list(): Promise<string[]>;
    /**
     * Get cache entry with metadata (for inspection)
     */
    getEntry(registryName: string): Promise<ManifestCache | null>;
    /**
     * Get cache statistics
     */
    getStats(): Promise<CacheStats>;
    /**
     * Clean up expired cache entries
     * @returns Number of entries removed
     */
    cleanup(): Promise<number>;
    /**
     * Check if cache exists for a registry
     */
    has(registryName: string): Promise<boolean>;
}
/**
 * Default cache manager instance
 */
export declare const manifestCache: ManifestCacheManager;
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