/**
 * AudioContextGuard - Robust AudioContext lifecycle management for background playback
 *
 * Handles:
 * - AudioContext suspension/interruption detection and recovery
 * - Browser tab visibility changes
 * - User gesture requirements for resume
 * - UI banner for manual resume when needed
 */
export type AudioContextState = 'running' | 'suspended' | 'interrupted' | 'closed';
export interface AudioContextGuardConfig {
    /** AudioContext instance to guard */
    audioContext: AudioContext;
    /** Callback when context state changes */
    onStateChange?: (state: AudioContextState) => void;
    /** Callback when user gesture is required to resume */
    onResumeRequired?: () => void;
    /** Callback when resume succeeds after user gesture */
    onResumeSuccess?: () => void;
    /** Enable debug logging */
    debug?: boolean;
}
export declare class AudioContextGuard {
    private audioContext;
    private onStateChange?;
    private onResumeRequired?;
    private onResumeSuccess?;
    private debug;
    private visibilityChangeHandler?;
    private focusHandler?;
    private blurHandler?;
    private pageShowHandler?;
    private stateChangeHandler?;
    private isActive;
    private resumeAttempts;
    private readonly MAX_AUTO_RESUME_ATTEMPTS;
    private lastResumeAttempt;
    private readonly RESUME_THROTTLE_MS;
    constructor(config: AudioContextGuardConfig);
    /**
     * Start monitoring AudioContext and attach event listeners
     */
    start(): void;
    /**
     * Stop monitoring and detach event listeners
     */
    stop(): void;
    /**
     * Manually ensure AudioContext is running (call from user gesture)
     */
    ensureRunning(): Promise<boolean>;
    /**
     * Get current AudioContext state
     */
    getState(): AudioContextState;
    private handleVisibilityChange;
    private handleFocus;
    private handleBlur;
    private handlePageShow;
    private handleStateChange;
    private checkAndResume;
    private attemptResume;
    private log;
}