/**
 * @file Data Prefetching
 * @description API and data prefetching utilities with caching, deduplication,
 * and stale-while-revalidate patterns.
 *
 * Features:
 * - API response prefetching
 * - GraphQL query prefetching
 * - Stale-while-revalidate
 * - Request deduplication
 * - Cache management
 * - Prefetch on interaction
 */
/**
 * Data prefetch configuration
 */
export interface DataPrefetchConfig {
    /** Enable data prefetching */
    enabled: boolean;
    /** Default cache TTL in ms */
    defaultTTL: number;
    /** Enable stale-while-revalidate */
    staleWhileRevalidate: boolean;
    /** Stale time before revalidation in ms */
    staleTime: number;
    /** Enable request deduplication */
    deduplicate: boolean;
    /** Deduplication window in ms */
    dedupeWindow: number;
    /** Maximum cache entries */
    maxCacheEntries: number;
    /** Include credentials */
    credentials: RequestCredentials;
    /** Default headers */
    defaultHeaders: Record<string, string>;
    /** Retry configuration */
    retry: {
        attempts: number;
        delay: number;
        backoff: 'linear' | 'exponential';
    };
    /** Debug mode */
    debug: boolean;
}
/**
 * Prefetch request options
 */
export interface PrefetchRequestOptions {
    /** HTTP method */
    method?: 'GET' | 'POST';
    /** Request headers */
    headers?: Record<string, string>;
    /** Request body (for POST) */
    body?: unknown;
    /** Cache TTL in ms */
    ttl?: number;
    /** Cache key (defaults to URL) */
    cacheKey?: string;
    /** Priority */
    priority?: 'high' | 'normal' | 'low';
    /** Skip cache and force fetch */
    force?: boolean;
    /** Tags for cache invalidation */
    tags?: string[];
}
/**
 * Prefetch result
 */
export interface PrefetchResult<T = unknown> {
    data: T | null;
    error: Error | null;
    fromCache: boolean;
    stale: boolean;
    fetchedAt: number;
}
/**
 * GraphQL query options
 */
export interface GraphQLPrefetchOptions {
    query: string;
    variables?: Record<string, unknown>;
    operationName?: string;
    ttl?: number;
    tags?: string[];
}
/**
 * Manages data prefetching with caching
 */
export declare class DataPrefetchManager {
    private readonly config;
    private cache;
    private pendingRequests;
    private listeners;
    constructor(config?: Partial<DataPrefetchConfig>);
    /**
     * Prefetch data from a URL
     */
    prefetch<T = unknown>(url: string, options?: PrefetchRequestOptions): Promise<PrefetchResult<T>>;
    /**
     * Prefetch multiple URLs
     */
    prefetchMany<T = unknown>(requests: Array<{
        url: string;
        options?: PrefetchRequestOptions;
    }>): Promise<Map<string, PrefetchResult<T>>>;
    /**
     * Prefetch a GraphQL query
     */
    prefetchGraphQL<T = unknown>(endpoint: string, options: GraphQLPrefetchOptions): Promise<PrefetchResult<T>>;
    /**
     * Get cached data without fetching
     */
    getCached<T = unknown>(cacheKey: string): T | null;
    /**
     * Check if data is cached
     */
    isCached(cacheKey: string): boolean;
    /**
     * Check if cached data is stale
     */
    isStale(cacheKey: string): boolean;
    /**
     * Invalidate cache by key
     */
    invalidate(cacheKey: string): boolean;
    /**
     * Invalidate cache by tag
     */
    invalidateByTag(tag: string): number;
    /**
     * Subscribe to cache updates
     */
    subscribe(cacheKey: string, callback: (data: unknown) => void): () => void;
    /**
     * Clear all cache
     */
    clearCache(): void;
    /**
     * Get cache statistics
     */
    getStats(): {
        entries: number;
        size: number;
        pendingRequests: number;
    };
    private executeFetch;
    private fetchWithRetry;
    private revalidate;
    private setCache;
    private evictOldest;
    private notifySubscribers;
    private generateCacheKey;
    private generateGraphQLCacheKey;
    private estimateSize;
    private sleep;
    private log;
}
/**
 * Get or create the global data prefetch manager
 */
export declare function getDataPrefetchManager(config?: Partial<DataPrefetchConfig>): DataPrefetchManager;
/**
 * Reset the manager instance
 */
export declare function resetDataPrefetchManager(): void;
/**
 * Prefetch data from a URL
 */
export declare function prefetchData<T = unknown>(url: string, options?: PrefetchRequestOptions): Promise<PrefetchResult<T>>;
/**
 * Prefetch a GraphQL query
 */
export declare function prefetchGraphQL<T = unknown>(endpoint: string, options: GraphQLPrefetchOptions): Promise<PrefetchResult<T>>;
/**
 * Get cached data
 */
export declare function getCachedData<T = unknown>(cacheKey: string): T | null;
/**
 * Invalidate cache by key
 */
export declare function invalidateData(cacheKey: string): boolean;
/**
 * Invalidate cache by tag
 */
export declare function invalidateDataByTag(tag: string): number;