/**
 * @file Unified Network Utilities
 * @description Standardized network information access, connection quality
 * detection, and online/offline status utilities.
 *
 * This module unifies patterns from:
 * - hooks/shared/networkUtils.ts
 * - utils/networkStatus.ts
 *
 * @module shared/network-utils
 */
/**
 * Connection type from Network Information API.
 */
export type ConnectionType = 'wifi' | '4g' | '3g' | '2g' | 'slow-2g' | 'ethernet' | 'bluetooth' | 'cellular' | 'none' | 'unknown';
/**
 * Effective connection type (speed-based).
 */
export type EffectiveType = 'slow-2g' | '2g' | '3g' | '4g';
/**
 * Network quality tier.
 */
export type NetworkQuality = 'excellent' | 'good' | 'fair' | 'poor' | 'offline';
/**
 * Network information from the Network Information API.
 */
export interface NetworkInfo {
    /** Whether the browser reports online status */
    online: boolean;
    /** Connection type (wifi, cellular, etc.) */
    type: ConnectionType;
    /** Effective connection type based on measured speed */
    effectiveType: EffectiveType;
    /** Estimated downlink speed in Mbps */
    downlinkMbps: number;
    /** Estimated round-trip time in milliseconds */
    rttMs: number;
    /** Whether data saver mode is enabled */
    saveData: boolean;
    /** Calculated quality tier */
    quality: NetworkQuality;
    /** Timestamp of measurement */
    timestamp: number;
}
/**
 * Get current network information.
 *
 * @returns Current network information with quality assessment
 *
 * @example
 * ```ts
 * const network = getNetworkInfo();
 * if (network.quality === 'poor') {
 *   // Show low-quality content
 * }
 * ```
 */
export declare function getNetworkInfo(): NetworkInfo;
/**
 * Check if browser is currently online.
 */
export declare function isOnline(): boolean;
/**
 * Check if current connection meets minimum quality requirement.
 *
 * @param minimum - Minimum required effective type
 * @returns True if current connection meets requirement
 */
export declare function meetsMinimumQuality(minimum: EffectiveType): boolean;
/**
 * Check if connection is considered slow.
 *
 * @param thresholds - Custom thresholds for slow detection
 */
export declare function isSlowConnection(thresholds?: {
    maxDownlinkMbps?: number;
    maxRttMs?: number;
}): boolean;
/**
 * Get human-readable quality label.
 */
export declare function getQualityLabel(quality?: NetworkQuality): string;
/**
 * Callback for network status changes.
 */
export type NetworkChangeCallback = (info: NetworkInfo) => void;
/**
 * Monitor network quality changes.
 *
 * @param callback - Function called when network quality changes
 * @returns Cleanup function to stop monitoring
 *
 * @example
 * ```ts
 * const unsubscribe = onNetworkChange((network) => {
 *   console.log('Network changed:', network.quality);
 * });
 *
 * // Later, cleanup
 * unsubscribe();
 * ```
 */
export declare function onNetworkChange(callback: NetworkChangeCallback): () => void;
/**
 * Listen for online status changes only.
 */
export declare function onOnlineChange(callback: (online: boolean) => void): () => void;
/**
 * Check if prefetching should be allowed based on network conditions.
 *
 * @param options - Prefetch configuration
 * @returns True if prefetching should proceed
 *
 * @example
 * ```ts
 * if (shouldAllowPrefetch({ minQuality: '3g', respectDataSaver: true })) {
 *   prefetchNextPage();
 * }
 * ```
 */
export declare function shouldAllowPrefetch(options?: {
    /** Minimum required effective connection type */
    minQuality?: EffectiveType;
    /** Skip prefetch if data saver is enabled */
    respectDataSaver?: boolean;
    /** Skip prefetch if offline */
    requireOnline?: boolean;
}): boolean;
/**
 * Get recommended resource loading strategy based on network.
 */
export declare function getLoadingStrategy(): 'eager' | 'lazy' | 'none';
/**
 * Get recommended image quality based on network.
 */
export declare function getRecommendedImageQuality(): 'high' | 'medium' | 'low';
/**
 * Ping an endpoint to check actual connectivity.
 *
 * Note: This function intentionally uses raw fetch() rather than apiClient because:
 * 1. It uses 'no-cors' mode which is only available with raw fetch
 * 2. Ping is a low-level network diagnostic, not an API call
 * 3. It must work with any URL, not just API endpoints
 *
 * @see {@link @/lib/api/api-client} for the main API client
 *
 * @param url - URL to ping
 * @param timeoutMs - Timeout in milliseconds
 * @returns True if ping succeeded
 */
export declare function pingEndpoint(url: string, timeoutMs?: number): Promise<boolean>;
/**
 * Measure actual round-trip time to an endpoint.
 *
 * @param url - URL to measure
 * @param samples - Number of samples to average
 * @returns Average RTT in milliseconds, or null if failed
 */
export declare function measureRtt(url: string, samples?: number): Promise<number | null>;